Structural, Optical, and Vibrational Behavior of V₂O₅-Doped Li₀.₅Na₀.₅NbO₃ Ceramics

Structural, Optical, and Vibrational Behavior of V₂O₅-Doped Li₀.₅Na₀.₅NbO₃ Ceramics | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Structural, Optical, and Vibrational Behavior of V₂O₅-Doped Li₀.₅Na₀.₅NbO₃ Ceramics Kamala Sujani Dasary, K.V. Ramesh, A. V. N. Ramalingeswara Rao This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8881891/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 03 Apr, 2026 Read the published version in Chemical Papers → Version 1 posted 9 You are reading this latest preprint version Abstract This study explores the thermal, optical, vibrational and structural properties of lead-free Li 0.5 Na 0.5 NbO 3 (LNN) ceramics to a different concentration of V 2 O 5 (0, 1, 3, 5, and 9 mol). The samples were prepared in the older solid-state method of reaction. The formation of a single phase orthorhombic perovskite structure was confirmed by X-ray diffraction (XRD) yet there was slight displacement of the XRD patterns implying that there were minimal secondary phases. The peaks of diffraction were evidence of the effective inclusion of the vanadium in the lattice. DSC analysis displayed that V 2 O 5 addition changed the optical investigations with the aid of UV-Vis spectroscopy displayed progressive changes in the optical band gap, which are indicative of a dopant alteration in the electronic structure created by defect states. Scanning electron microscopy (SEM) showed improvement in grain growth and densification. FTIR and Raman spectroscopy of Nb-O bond vibrations and local structural order showed that these results were found at optimal doping concentrations, further supporting these findings. The V 2 O 5 was found to enhance the microstructural and functional properties of LNN ceramics, and they will be suitable in future lead-free electronic and dielectric devices. Lead-free ceramics Perovskite structure Optical band gap X-ray diffraction (XRD) Microstructure Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 INTRODUCTION Lead-based ceramics have been of keen interest as working material in recent decades due to their exceptional ferroelectric, dielectric and piezoelectric properties and are important in sensors, actuators as well as transducers [ 1 , 2 ]. Through research however, attention has shifted to development of environmentally friendly alternatives due to the toxicity of lead and its high impact on human health and the environment. lead-free ferroelectric ceramics that is friendly and has similar or better functionality. Their structural versatility, compositional versatility, and excellent electrical properties have made the perovskite-based systems the most promising of the many lead-free material families including tungsten-bronze, layered perovskite, and perovskite-type structures [ 3 – 5 ]. In this regard, alternatives of lead zirconate titanate (PZT) have been well studied such as alkali niobates, barium titanate, modified alkali bismuth titanates, and materials with morphotropic phase boundaries (MPB) [ 6 – 8 ]. Lithium sodium niobate (Li 0.5 Na 0.5 NbO 3 ; LNN) has become one of the most attractive lead-free ferroelectric systems in the alkali niobate family because of its large dielectric constant. Maximum anisotropy, low piezoelectric coefficients, minimal anisotropy, and chemical stability [ 9 , 10 ]. Li + is replaced by Na + in the perovskite lattice further enhancing polarization alignment due to the reduced ionic radius of Li + compared to Na + and this enhances ferroelectric properties. These advantages are notwithstanding the difficulty of producing stoichiometric and dense LNN ceramics because both Li 2 O and Na 2 O are highly volatile at high sintering temperatures and because of this, secondary phases are formed, densification is inadequate, and dielectric loss is elevated [ 11 – 13 ]. The variables influence the reproducibility and electrical property of LNN ceramics. These difficulties have been overcome by multiple modern sintering techniques, such as spark plasma (SPS), hot isostatic (HIP), and template grain growth (TGG) to achieve a uniform microstructure and high density in LNN ceramics [ 14 – 16 ]. These methods have demonstrated to enhance piezoelectric and dielectric responses although tight control over processes and expensive equipment is needed rendering them not to be applicable to large-scale or industrial production. Another and more effective way of improving the densification and electrical properties is to incorporate the relevant dopants in the A- and/or B-sites of the perovskite lattice [ 17 – 20 ]. Different dopants alter the grain growth kinetics, the phase stability, and the conduction mechanism and enables the structural and functional properties to be tailored. As an example, it has been demonstrated that addition of CuO and ZnO can enhance the defect of formation and enhance other mechanical quality variables without affecting the piezoelectricity activity [ 21 ]. Likewise, it is possible to accomplish synergistic Improvements in the performance of Li-Na-Nb based ceramics through procedures that involve chemical modification and microstructural texturing [ 22 ]. Vanadium pentoxide (V 2 O 5 ) has currently been recognized as an effective sintering aid to electroceramics due to its low melting point ([?] 690 o C), which allows easier attainment of liquid-phase-aided sintering and promotes improved mass transport and densification [ 23 – 25 ]. In perovskite ceramics, small amounts of V 2 O 5 can significantly reduce the sintering temperature, enhance the uniformity of the microstructure and enhance the dielectric and electrical conductivity characteristics. In addition, the more recent developments, such as cold-sintering-assisted sintering (CSAS) also showed the promise of controlling alkali volatilization and enhancing piezoelectric constants [ 26 ]. It has been proposed that machine-learning-directed compositional optimization will be an effective approach to the development of high-performance lead-free piezoelectric ceramics in the future [ 27 ]. This study focuses on the structural, thermal (DSC), optical, and vibrational properties of Li 0.5 Na 0.5 NbO 3 (LNN) ceramics to which the V 2 O 5 concentration was added (0, 1, 3, 5, and 7 weight percent). The 5 and 9 mol% were synthesized using the traditional solid-state reaction method. There is particular emphasis on the effect of V 2 O 5 doping on lattice dynamics, chemical bonding, optical band gap behaviors and grain boundary conduction mechanisms. All of them include differential scanning calorimetry (DSC), optical analysis (UV-Vis), spectral analysis (Raman), the Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and comprehensive characterization. The findings provide useful knowledge on the use of addition of vanadium to enhance the overall performance of lead-free LNN ceramics. EPERIMETAL PROCEDURE The conventional solid-state reaction approach, which is a well-known method in the manufacturing of perovskite-based oxide ceramics, was used to create lithium sodium niobate doped vanadium (LNNV) ceramics because it is thought to be dependable in achieving phase purity and compositional homogeneity. Raw materials and powder processing The initial precursors were analytical-grade lithium carbonate (Li₂CO₃), sodium carbonate (Na₂CO₃), niobium pentoxide (Nb₂O₅), and vanadium pentoxide (V₂O₅) of high purity (99.95%).These compounds were weighed in their exact stoichiometric ratios of the nominal compositions Li₀.₅Na₀.₅NbO₃ + xV₂O₅ (x = 0, 1, 3, 5, and 9 mol%). The powders were first dry-mixed and then ground manually in an agate mortar with a pestle for about 8 hours to a fine state to obtain a fine distribution of the particles and to ensure a minimum level of compositional inhomogeneity. The long grinding process was important in that close contact between the constituent oxides and carbonates was achieved, thereby facilitating solid-state diffusion during the later thermal treatment. Calcination, pre-sintering treatment The homogenized powder mixtures were calcined at an ambient temperature of 1050°C in alumina crucibles over 5 hours. The aim of the calcification step was to begin solid-state diffusion, aid the breaking down of carbonates, and enhance the appearance of the perovskite KNN stage. The calcined powders had been reground with care to dispense agglomerates that had formed during heating and were then mixed with a few drops of an aqueous solution of polyvinyl alcohol (PVA) (a temporary binder) to facilitate pelletization. Pellet fabrication, sintering. The ready powders were molded into cylindrical milled pellets of 13 mm diameter and thickness of about 2 mm by use of a uniaxial hydraulic press at a pressure of 100 MPa. The green compacts were stacked on alumina plates that had been covered with platinum to eliminate contamination and sintered in air at 1100°C over a duration of 1.5 hrs. This sintering stage guaranteed sintering and an increase in the grain size, as well as the formation of a mechanically strong ceramic body. The pellets after sintering were polished on both sides with successively finer grades of silicon carbide (SiC) abrasive papers to form smooth, parallel, and uniform surfaces applicable to structural and electrical characterizations. Density measurements The theoretical densities of all the prepared compositions were determined using the corresponding molecular masses and crystallographic parameters. The Archimedes principle was used to determine the experimental bulk densities of the sintered specimens, with xylene being used as the immersion liquid. The sample codes, compositional details, theoretical densities calculated, and bulk densities measured experimentally are noted in Table 1 . Table 1 Sample codes, compositional details, theoretical and bulk densities of the prepared samples Composition Code Density (g/cc) Theoretical Experimental Li 0.5 Na 0.5 NbO 3 + 0V 2 O 5 LNNV 0 4.582 4.329 Li 0.5 Na 0.5 NbO 3 + 1V 2 O 5 LNNV 1 4.606 4.386 Li 0.5 Na 0.5 NbO 3 + 3V 2 O 5 LNNV 3 4.628 4.442 Li 0.5 Na 0.5 NbO 3 + 5V 2 O 5 LNNV 5 4.643 4.507 Li 0.5 Na 0.5 NbO 3 + 9V 2 O 5 LNNV 9 4.669 4.418 Microstructure and spectroscopy Utilizing RIGAKU D/Maz 2550V and BRUKER D8 Advance XRD equipment, the crystal structure of the material was determined using X-ray diffraction (XRD) with CuKα radiation. Microstructural research the grain size was measured using Scanning Electron Microscopy (SEM) with a JEOL JSM 5600 equipment with a resolution of 3.5 nm. A modulated differential The thermal properties of the ceramic samples were assessed using a scanning calorimeter (MDSC, TA Instruments Model 2910). Each sample was sealed in aluminum crucibles at a rate of approximately 15 mg each, and then subjected to a controlled heating rate of 10°C per minute. Throughout the experiments, dry nitrogen gas was used to cleanse the chamber and keep it in an inert atmosphere. The Curie temperature (T c ) was calculated from the DSC plots using the onset point method, with a measurement uncertainty of ± 1°C. A JASCO V670 UV-Vis spectrophotometer was used to acquire the room-temperature optical absorption spectra in the wavelength range of 200–1000 nm. The instrument's software was then used to analyze the spectra. Samples were collected from polished ceramic surfaces to guarantee precise optical analysis. Furthermore, a Perkin-Elmer FT-IS was used to do Fourier Transform Infrared (FTIR) spectroscopy. Infrared spectra in the range of 400 to 1500 cm -1 were captured by analyzing the samples using a model 1605 spectrometer. A Jobin-Yvon Horiba Raman spectrometer was used to The LABRAM HR-800 spectrometer, which had a confocal microscope, was also used to make Raman measurements. A microscope and an excitation source were used for the excitation. An Ar + laser beam with a wavelength of 488 nm that produces high spectral resolution and accurate Raman shifts. RESULTS AND DISCUSSIONS X-ray diffraction The X-ray diffraction (XRD) spectrums of Li 0.5 Na 0.5 NbO 3 ceramics with varied percentages of V 2 O 5 (x = 0, 1, 3, 5, and 9 mol) are shown. Figure 1 shows that all compositions have the clear evidence of diffraction peaks that can be attributed to the presence of a perovskite-based orthorhombic structure, which is consistent with the regular JCPDS card No. 32–0822 [ 28 ]. V 2 O 5 addition does not cause the appearance of other secondary or impurity phases, meaning that the dopant and the host lattice were completely compatible in chemistry and there was a complete reaction between the two, exclusively in the solid state. Diffraction peaks positions are slightly varied and the relative peak intensities change when the concentration of V 2 O 5 is increased and this indicates that there are some small structural changes that occur when Vanadium is added. The 2θ range of 32 o -33 o , and especially, is distinctly separated into two different reflections at the values of 32.4 o and 32.9 o , as observed in Fig. 2 . This bifurcation is an indication of both tetragonal and orthorhombic phases that exist thus V 5+ doping induces local structural changes in the perovskite structure. To determine this structural change, the intensity ratio (I 1 /I 2 ) of the split peaks in the 32 o -33 o region was calculated (see Fig. 3 ). Even the undoped sample (x = 0) retains a highly orthorhombic structure and a rather low I 1 /I 2 ratio. The ratio rises tremendously when doped with 1 mol% V 2 O 5 , showing a higher percentage of the tetragonal phase. The tetragonal phase is maximized at the maximum value of I 1 /I 2 which is at x = 1 mol%. The ratio gradually decreases before this concentration (x ≥ 3 mol%), which implies that a higher doping concentration results in a restoration of orthorhombic symmetry. These findings can be explained by the ionic size mismatch between the replacing cation V 5+ (0.59 A) and the host Nb 5+ ion (0.69 A). Internal chemical pressure and local stress that the substitution of the B-site with smaller V 5+ ions causes destabilizes the orthorhombic lattice and promotes the formation of a more symmetrical tetragonal phase at reduced concentrations. At greater concentrations of V 2 O 5 , however, over substitution causes a greater lattice distortion and relaxation of stress, which re-forms the orthorhombic ordering through structural re-equilibration [ 29 – 30 ]. Also, the systematic shift of the main diffraction peaks to higher 2θ values with increase in V concentration is indicative of a reduction in lattice parameters which is consistent with the introduction of smaller V 5+ ions into the Nb 5+ sites resulted in a lattice contraction. Besides modifying the dimensions of the unit cell, this contraction can also affect the crystal symmetry, bonding environment and stability of the perovskite phase. According to the XRD results, it can be concluded that V 2 O 5 doping affects the crystal structure of Li 0.5 Na 0.5 NbO 3 ceramics on a large scale even with quite a small percentage of doping (x ≈ 1%). More concentrations cause an increase in lattice strain and re-establishment of the orthorhombic phase, and 1 mol% causes a partial transition to tetragonal symmetry. To control the microstructural and functional properties of LNN-based lead-free piezoelectric ceramics, such controlled structural change with V 2 O 5 doping is crucial [ 31 ]. Scanning Electron Microscopy (SEM) The surface morphology of the sintered Li 0.5 Na 0.5 NbO 3 + x mol% V 2 O 5 ceramics (x = 0, 1, 3, 5, 9) was studied using scanning electron microscopy. (SEM), as depicted in Fig. 4 . The polycrystalline microstructure of all the samples, which have distinct grain boundaries, favors the creation of a single-phase perovskite matrix. Vanadium oxide has a major effect on grain shape, size, and porosity, indicating that it is essential for the densification process. The undoped LNN sample (x = 0) contains a small number of intergranular pores and comparatively small and equiaxed grains of the sample with distinct grain boundaries. Its average grain size is 0.9–1.2 mm, which means that the grain growth is suppressible in the sintering environment. Alkali elements are unstable during sintering, limiting densification and resulting in low porosity in alkali niobate-based ceramics, as seen in this morphology [ 32 ]. Adding 1 mole percent alters the grain size to 1.3–1.7 micrometers, and the microstructure narrows down. This improvement can be explained by the liquid nature of the sintering of V₂O₅ that melts at a low temperature (approximately 690°C) and allows viscous flow and diffusion along grain boundaries [ 33 ]. The reduction in porosity and smooth grain boundaries translates to higher grain boundary mobility and effective diffusion of ions during the sintering process. The microstructure of the 3 mol percent V₂O₅ sample had a uniform distribution of well-faceted grains ranging between 1.9 and 2.3 mm, thus indicating optimal densification. The grains appear to be denser, and they have fewer pores and no visible secondary phases. The perfect level of V₂O₅ is also a powerful sintering aid in which LNN grain rearrangement and merging can occur without creating any adverse impacts. Separative action of the liquid phase is brought about by [ 34 ]. This improvement in the uniformity of the microstructure is advantageous towards the realization of uniform electrical and dielectric values. Above the level of higher concentrations of V₂O₅ (5 mol%), the particles are irregular and even somewhat extended, which shows the local melting or agglomeration. The average grain size is between 2.0 and 2.4 mm, and there are a few areas of glassy intergranular between the grain boundaries. Such glassy areas are presumably due to the segregation of surplus V₂O₅ at the grain boundaries during the sintering process that leads to partial wetting of the grain boundaries [ 35 ]. Although the densification is high, the presence of a second phase may introduce interfacial potential barriers that hinder the charge transfer and dielectric relaxation. Which inhibit carrier cross-grain flow. The 9 mol percent V₂O₅ blend is irregular in the structure of the grains and melted spots on the surface. The grain boundaries are smeared (due to the constant liquid-like state of the excessive V₂O₅). The overall microstructural uniformity is damaged despite the average grain size, which is 2.5–2.9 mm. Over-sintering results in excessive production of liquid phase and consequently vanadium-rich segregations and secondary phases, as these features indicate. This can cause local lattice distortion and increased oxygen vacancies as well as potential changes in the valence states (V 5+ → V 4+ ) that not only improve electrical properties but also increase dielectric loss. Based on SEM data, V₂O₅ is an aid in sintering and a structural modulator. Moderate doping (1–3mol%) enhances grain growth, densification, and uniformity, while greater doping concentrations (≥ 5 mol%) cause microstructural heterogeneity and liquid-phase production. The observed changes in dielectric relaxation behavior and a.c. conductivity with increasing V₂O₅ concentration are well correlated with the microstructural evolution, which shows an increase in densification and a decrease in Increasing grain boundary resistance improves conduction pathways [ 36 ]. Differential scanning calorimetry The thermal behavior of current ceramics with varying quantities of V 2 O 5 addition was studied using differential scanning calorimetry (DSC) in order to comprehend the effect of the integration of vanadium into the ferroelectric-paraelectric phase shifts. Figure 5 (a and b) displays the DSC thermograms for all formulations. DSC analysis is a trustworthy method for identifying thermal occurrences related to structural phase transitions in perovskite-type niobate ceramics, which have a direct impact on their ferroelectric and dielectric properties. The DSC curve of the pure LNN sample (x = 0 mol%) shows two clear endothermic peaks. The initial one, a sharp peak at around 420°C, denotes the ferroelectric phase shift between the orthorhombic and tetragonal (O–T) phases. The second, wider endothermic characteristic, which occurs between 480 and 500°C, corresponds to the tetragonal-to-cubic (T-C) transition, which is linked to the shift to the paraelectric state. These two clearly defined transitions are typical of alkali niobate systems and point to a high degree of long-range ferroelectric order within the undoped LNN matrix. After the introduction of 1 mol% V₂O₅, both transition peaks remain, but the O–T transition moves somewhat towards higher temperatures (between 430 and 435°C), while the The T–C transition still occurs between 490 and 500°C, with only a slight sharpening. This behavior indicates greater structural stiffness of the lattice and improved thermal stability of the ferroelectric phase. In the perovskite lattice, the replacement of Nb 5+ ions (0.69 Å) with smaller V 5+ ions (0.59 Å) at the B-site creates chemical pressure, which lowers octahedral distortion and increases the strength of the Nb/V–O bond. As a result, more thermal energy is needed for the O–T phase transition. This stabilization effect is supported by Raman and FTIR experiments, which demonstrate that the vibrational bands have narrowed and shifted towards the blue range, while the anharmonicity of the lattice has decreased and interactions between the metals and oxygen have strengthened. A slight decline in temperature is observed as the concentration of vanadium increases to 3 mol%. The expansion of the thermal event indicates the initiation of the diffuse phase transition (DPT) behavior. Because of the imbalance of charges, the addition of more V 5+ ions results in the strain of the lattice and oxygen vacuity, which provides local structural disruption. These defects promote a relaxor-like behavior, decrease long-range interaction between dipoles, and disrupt the coherence of the ferroelectric domains[ 37 ]. The wide, flat peaks in the DSC thermograms manifest this compositional deformity. The DSC curve of the 5 mol percent V₂O₅-doped sample reveals only a single broad endothermic peak at 470–480°C, and no clear distinction between the O-T and T-C transitions is apparent. Such a combination of transitions implies the formation of an intermediate or mixed-phase space where orthorhombic, tetragonal, and pseudo-cubic domains can coexist over a large temperature range. It may be explained by excess V incorporation resulting in local non-centrosymmetric distortions and enhanced microstrain. The diffuse and smeared nature of the transition suggests a gradual and not abrupt phase transition development, as is expected of the evolution of compositional heterogeneity within the lattice. The DSC thermogram of 9 mol% V₂O₅ has a faint and broad hump at approximately 480°C, but no distinct endothermic peaks. The partial amorphization of the LNN matrix and the absence of a distinct phase change indicate significant structural disorder. Comprehensive V 5+ doping leads to serious lattice distortion, the formation of oxygen vacancies, and the disruption of octahedral bonding. Those effects inhibit ferroelectric ordering and trigger relaxor-type behavior, where there are only local polar regions with no long-range order. The findings agree with Raman and XRD data that show peak broadening and band blurring at greater doping levels, supporting a decrease in crystallinity and an increase in internal stress. Due to the following reasons, the DSC analysis demonstrates unequivocally that a small amount of V 2 O 5 doping (x = 1 mol%) improves lattice stability and raises the temperature of the ferroelectric phase transition: decreased lattice distortion and the reinforcement of Nb/V–O connections. However, higher doping concentrations (x ≥ 3 mol%) cause chemical and structural disorder, which results in the suppression of ferroelectric–paraelectric transformations and broad, diffuse, or fused thermal transitions[ 38 ]. These results show that the phase behavior of LNN + V₂O₅ ceramics may be tuned based on their composition, allowing for the strategic optimization of temperature stability and dielectric characteristics for piezoelectric actuators, transducers, and sensors. Optical Properties UV-visible spectroscopy was employed to investigate the optical properties of Li 0.5 Na 0.5 NbO 3 + x mol% V 2 O 5 ceramics for x values of 0, 1, 3, 5, and 9, as seen in Fig. 6 , within the wavelength range of 200 to 1000 nm. The influence of V₂O₅ incorporation on the electronic structure and optical transitions of the system is evidenced by the broad absorption edges in the spectra, which systematically vary with increasing vanadium concentration. As the quantity of V 2 O 5 increases from 0 to 9 mol%, the optical transmittance significantly decreases. The LNN + 3 mol% V 2 O 5 combination demonstrates the highest transmittance, approximately 60% within the visible spectrum, while the pure LNN sample exhibits moderate transparency. This result signifies that the optical clarity and scattering losses are enhanced at this doping dose. The enhancement in transmittance at intermediate V₂O₅ concentrations is primarily attributed to the reduction in surface porosity, the finer grain size (~ 400 nm), and the augmentation of V₂O₅'s fluxing action during sintering [ 39 ], which induces crystallinity. Higher amounts of V₂O₅ (≥ 5 mol%) cause the microstructure to become denser with fewer grain boundaries, which reduces light scattering and improves transmission through the bulk. However, at higher V₂O₅ levels, the transmission decreases noticeably, suggesting increased absorption that may result from the introduction of localized electronic levels within the band gap due to the creation of vanadium-related defect states or secondary glassy phases [ 40 ]. To analyze the optical absorption behavior quantitatively, the absorption coefficient (α) was derived from the absorbance data using a formula. The dependence of the absorption coefficient near the fundamental edge follows the Tauc relation [ 41 , 42 ]. (αhν) = B(hν − E g ) n (2) where B is a constant, hν is the photon energy, Eg is the optical band gap, and n characterizes the nature of the electronic transition (n = 1/2 for direct allowed and n = 2 for indirect allowed transitions). Both direct and indirect optical band gaps were determined by plotting (αhν)² and (αhν)¹ᐟ² versus photon energy (hν) and extrapolating the linear portions to the energy axis, as shown in Fig. 7 (a, b). The estimated indirect band gap (Eg, indirect) values range from 3.13 eV (x = 0) to 3.01 eV (x = 9), whereas the direct band gap (Eg, direct) values vary from 3.39 eV for the undoped sample to 3.26 eV for the 9 mol% V₂O₅ composition. The observed redshift of the absorption edge with increasing vanadium concentration indicates a band gap narrowing effect. This reduction in band gap energy is ascribed to several factors. First, V⁵⁺ ions partially replace Nb⁵⁺ at the B-site because their ionic radii are similar (V⁵⁺ = 0.59 Å, Nb⁵⁺ = 0.64 Å). V-O states are localized right below the conduction band. These states are shallow levels of donor so that they can be excited electronically at lower photon energy. Secondly, combined valence states (V 5+ /V 4+ ) and associated oxygen vacancies result in localized defect levels, which enhance sub-bandgap absorption. The overlap of localized states with the tail of the conduction band increases with increased concentration of V 2 O 5 and decreases the effective band gap a common phenomenon in oxide systems with transition metals [ 43 ]. Moreover, substitution of Nb 5+ by V 5+ leads to structural variations that bring about local variations in the symmetry of NbO 6 octahedra and the orbital hybridization of the V-O and Nb-O bonds. The interaction of the vanadium d-orbitals with the oxygen p-orbitals causes band tailing at the absorption edge which leads to the redshift in the optical spectra [ 38 ]. The production of defect-generated energy levels within the forbidden gap region is also enhanced by the rise in absorption intensity with the rise in the concentration of vanadium. The value of optical band gaps of direct transitions is 3.155–3.398 eV, and those of indirect transitions are 3.018–3.23 eV, which are consistent with the values, with previously demonstrated values of the ion-doped perovskite oxides and alkali niobate-based ferroelectrics. The increased transmittance observed in the samples with lower content of V 2 O 5 is attributed to the fact that larger band gap is usually associated with increased optical transparency and reduced absorption. A decrease in the size of the gap with increased levels of doping is a sign of increased electronic polarizability and an increase in the concentration of charge carriers, and it can also affect the previously mentioned dielectric and conductive properties. The UV–Vis analysis confirms that V₂O₅ incorporation modifies the electronic band structure of LNN ceramics by introducing defect-related states and structural distortions. Moderate V₂O₅ addition (1–3 mol%) optimizes the balance between transparency and conductivity, whereas higher concentrations (≥ 5 mol%) promote defect-level formation and increased optical absorption. The magnitude of structural disorder and flaw density in the material can be deduced further from the tail of the absorption edge. This area adheres to the Urbach empirical equation [ 44 ]. The formula for the absorption coefficient as a function of photon energy is α(hν) = α₀ exp(hν/Eu). Here, α₀ is a constant, and E u is the Urbach energy, which reflects the width of the localized tail states inside the band gap. As illustrated in Fig. 8 , the E u values were derived from the slope of the linear section of the graph between ln(α) and hν. The expected variation in E values increased a bit with the quantity of V 2 O 5 added (i.e., increased disorder and defect generation), with a range of 0.29 eV (x = 0) up to 0.38 eV ( x = 9 mol%). This enhancement of E could be attributed to the enhanced oxygen vacuity concentration and local lattice distortions generated by V 5+ / V 4+ ions. The forbidden band caused by the coexistence of these defect states within the effective optical band gap lowers the effective optical band gap. The negative dependence that appears between the band gap between E and E9 and the disorder is in agreement with the previously observed correlated barrier hopping and band tailing phenomena on other oxide systems doped with vanadium [ 45 , 46 ]. Thus, the concomitant reduction in the band gap and the increase in the Urbach energy are indicative of the formation of fault-generated localized states, which are the cause of observed optical redshift and increased absorption of highly-doped samples. Spectroscopic Studies Structural changes and vibrational behavior of Li 0.5 Na 0.5 NbO 3 (LNN) ceramics caused by V 2 O 5 replacement was studied by Fourier Transform Infrared (FTIR) and Raman spectroscopies. These methods are quite susceptible to variations in the local bonding environment, especially in complex perovskites that have the ability of oxygen octahedral distortions and cationic replacements that can affect the phonon structure and lattice symmetry. FTIR spectra The infrared absorption spectra of Li₀.₅Na₀.₅NbO₃ + xV₂O₅ ceramics (x = 0, 1, 3, 5, and 9 mol%) were recorded in the spectral range of 400–4500 cm⁻¹. The normalized FTIR spectra, shown in Fig. 8 , show significant absorption characteristics between 400 and 1600 cm⁻¹, primarily caused by metal-oxygen vibrations of the niobate and vanadate networks. The spectra are limited to the 400–1800 cm⁻¹ range for clarity. Each spectrum was deconvolved using Gaussian fitting with 8–10 components, as shown for the 3 mol% V₂O₅-doped sample in Fig. 9 . Table 2 lists the deconvolved peak locations along with their respective assignments. The undoped Li₀.₅Na₀.₅NbO₃ sample displays distinctive absorption bands at around 400, 517, 583, and 649 cm⁻¹. These are thought to be caused by the intrinsic vibrations of NbO₆ octahedra, which are common in perovskite-type niobates. The 400 cm⁻¹ band is associated with Nb-O bending, the 517 cm⁻¹ band with O-Nb-O deformation, the 583 cm⁻¹ band with symmetric Nb-O stretching, and the 649 cm⁻¹ band with asymmetric Nb-O stretching oscillations. These characteristics corroborate the presence of Nb⁵⁺ ions in octahedral coordination within the ABO₃ lattice framework [ 47 – 49 ]. New absorption bands appear at around 765, 829, and 1060 cm⁻¹ when V₂O₅ is added, which are not present in the undoped material. These are assigned to vanadium-oxygen vibrations: the 765 cm⁻¹ band to V–O–V bending or symmetric stretching, the 829 cm⁻¹ band to terminal V = O stretching, and the asymmetric V = O stretch at the 1060 cm⁻¹ band. The formation of vanadate (VO₄ or VO₅) units is indicated by the emergence of these new modes, indicating either a partial substitution of Nb⁵⁺ by V⁵⁺ or the development of vanadium-rich secondary phases. Such replacement is structurally conceivable given that V⁵⁺ (0.59 Å) and Nb⁵⁺ (0.64 Å) have similar ionic radii and oxidation states [ 50 ]. Furthermore, as the amount of V₂O₅ increases, local lattice distortion is indicated by the somewhat altered frequency and intensity of the Nb–O stretching and bending bands (517–649 cm⁻¹). These variations in symmetry may lead to the potential formation of oxygen vacancies or defect dipoles. These effects change the polarizability and bonding strength of the NbO₆ network, which aligns with the behavior seen in other perovskite systems modified by V₂O₅ [ 51 ]. In the low-frequency range (below 400 cm⁻¹), there may be modest contributions from Li-O and Na-O lattice oscillations or their interaction with Nb-O modes. The overall symmetry of the lattice is affected by the differing ionic radii of the Li⁺ and Na⁺ ions (Li⁺ ≈ 1.64 Å; Na⁺ ≈ 1.39 Å), even if these ions are just moderately infrared active and dynamic inside the perovskite structure [ 52 ]. The broad bands around 1520 cm⁻¹ and 1650 cm⁻¹ are attributed to the stretching of trace organic residues and the bending of adsorbed water's H–O–H bonds, respectively. Their intensity may somewhat rise with increased V₂O₅ concentration, maybe as a result of improved surface reactivity and porosity, which facilitate moisture absorption [ 53 ]. In general, the gradual changes in FTIR spectra with increasing V₂O₅ concentration represent a combination of (i) NbO₆ octahedral distortion, (ii) the production of V–O–V and V = O units, and (iii) small lattice disturbances caused by the effects of A-site cations. As a result, V₂O₅ functions as both a structural modifier and a sintering aid, changing the local bonding environment that may have an impact on the dielectric and electrical characteristics of the ceramics [ 54 ]. Table 2 Band positions and corresponding vibrational assignments of FTIR and Raman spectra for all ceramic compositions band position (cm⁻¹) Spectroscopic technique Vibrational assignment Effect of V 2 O 5 mol% 150–180 Raman Translational mode of A-site cations (Li⁺/Na⁺) External vibration of alkali ions in perovskite lattice Below 400 FTIR/ Raman Lattice and translational vibrations Collective vibrations of perovskite framework involving A- and B-site cations 240–270 Raman O–Nb–O bending vibration Sensitive to local lattice distortion and oxygen positional disorder 330–360 Raman Octahedral tilt / O–B–O bending Reflects structural distortion and tilting of NbO 6 units 430–470 FTIR/ Raman Symmetric Nb–O stretching / lattice vibration Represents A–O–B type vibration and perovskite lattice mode 520–560 FTIR O–Nb–O bending vibration Internal deformation mode of BO 6 octahedra 600–650 FTIR/Raman Nb–O stretching vibration in NbO₆ octahedra Strong characteristic band of orthorhombic perovskite structure 710–730 Raman Nb–O–V stretching mode Confirms partial substitution of V 5+ at B site in the perovskite lattice 780–810 FTIR Nb–O–V / Nb–O–Nb asymmetric stretching Arises from corner-sharing BO 6 octahedra; slightly shifts with V 2 O 5 content 850–890 FTIR/Raman V = O stretching vibration Characteristic of terminal vanadyl (V ⁵ ⁺–O) bonds; indicates V₂O₅ incorporation or surface segregation 950–980 Raman Short V = O terminal bond stretching Evidence of localized vanadyl species or minor V 2 O 5 phase at high doping 1630–1650 FTIR H–O–H bending vibration Physically adsorbed water molecules on ceramic grains 3450–3550 FTIR O–H stretching vibration Due to adsorbed surface hydroxyl groups and moisture Raman spectra Figure 10 shows the room-temperature Raman spectrum of Li 0.5 Na 0.5 NbO 3 + xV 2 O 5 (x = 0, 1, 3, 5, and 9 mol%) ceramics. The deconvolution of each spectrum was done with six to seven Gaussian functions to ascertain correctly the position and relative intensity of the Raman bands. Figure 11 provides an example of this deconvolution of the V₂O₅-doped 5 mol% sample. Table 2 lists the deconvolved peak locations along with their respective assignments. The presence of the observed Raman bands can be broadly grouped into three areas, namely, the low-frequency (less than 300 cm⁻¹), mid-frequency (250–650 cm⁻¹), and high-frequency (800–900 cm⁻¹) regions. Table 3 presents the local maxima and their associated positions. A number of sharp Raman modes can be observed in the undoped Li 0.5 Na 0.5 NbO 3 (LNN) sample, which is an indication of an ordered orthorhombic (Amm2) symmetry. The vibrations with modes close to 130–138 cm⁻¹ are attributed to the translational vibration of A-site cations (Li⁺/Na⁺) with the NbO₆ octahedral structure [ 55 , 56 ]. As the content of V₂O₅ rises, there is a slight but appreciable movement of these low frequencies in the form of a shift. For the 5 mol% sample, the translational peak is observed at 155 cm⁻¹, while for the 9 mol% doping, it shifts to 145 cm⁻¹, and then it is observed again at 152 cm⁻¹ for a higher concentration. This difference is attributed to the variation in A-site dynamics, as well as changes in local strain, which are brought about by lattice distortion and mass fluctuations with the incorporation of vanadium [ 57 ]. At middle frequency (250–650 cm⁻¹), several bands are observed at approximately 213, 248, 270, 560, and 620 cm⁻¹. These are credited to Nb-O bending (υ 4 , υ 5 , υ 6 ) and asymmetric stretching vibrations of NbO 6 octahedra [ 18 , 19 ]. The 256 cm⁻¹ band is near the Nb-O bending (υ₅) mode that is sensitive to lattice distortion. This mode is split at increased V₂O₅ doping, and a second peak appears between 250 and 300 cm⁻¹, indicating that there are two different NbO₆ environments or both orthorhombic and tetragonal phases. This finding conforms to the XRD results, which indicated a gradual change of orthorhombic structure to tetragonal structure [ 58 ]. The symmetrical octahedra stretch (υ 1 ) mode of the NbO 6 is attributed to a strong Raman band at 615 cm⁻¹. This mode is subjected to systematic frequency shift and broadening with an increase in the concentration of V₂O₅. The transition to higher wavenumbers indicates the reduction of the length of Nb-O bonds due to the partial replacement of Nb⁵⁺ (ionic radius 0.64 Å) by the smaller V⁵⁺ ion (0.54 Å), which caused the strengthening of bonds and the decrease in lattice symmetry [ 59 ]. The development of the υ 1 band position with the increase in vanadium content is given in Fig. 12 , which proves the lattice contraction due to the V doping. Another band is observed at the high frequency (800–900 cm⁻¹) at about 860 cm⁻¹ in samples with V₂O₅, but not in the undoped LNN. It is the highest peak because of the V = O terminal stretching vibration, which is the result of tetrahedral or distorted octahedral units of vanadate (VO₄/VO₅) [ 50 , 51 ]. The onset of this mode is a pointer to successful vanadium incorporation by the LNN lattice, either by replacing the Nb site or by occupying interstitial positions. This high-frequency band also indicates that the partial redistribution of charges and the possible creation of mixed-valence species of V⁴⁺/V⁵⁺ may occur and affect the electronic processes in conductivity and polarization through defects. The half maximum and full width (FWHM) of υ 1 and υ 5 modes have a positive relation with the quantity of vanadium, indicating the presence of more phonon scattering caused by local lattice disorder. This expansion implies increased dynamic coupling of octahedrals to a greater extent of structural distortion, particularly in the region of the morphotropic phase boundary (MPB), where compositional inhomogeneity is intense [ 60 ]. The general trend in the Raman data shows that the addition of V₂O₅ changes the vibrational dynamics of both the A-site and B-site, adds new V-O-related modes, and causes the structural transformation of the orthorhombic to tetragonal symmetry. The observed increase in the dielectric, piezoelectric, and electrical behavior of the doped LNN ceramics correlates with these structural changes. CONCLUSIONS The current work thoroughly investigated the effect of V 2 O 5 doping of the structural, optical, vibrational, and thermal properties of Li 0.5 Na 0.5 NbO 3 (LNN) ceramics obtained by the process through the conventional solid-state methods. The most important findings are enumerated as follows: The x-ray diffraction showed that the structure of all samples was single-phase orthorhombic perovskite. Partial with the low level V 2 O 5 doping (x = 1 mol%) The simultaneous presence of the orthorhombic and tetragonal phases, but the larger levels of doping (x ≥ 3 mol%) led to lattice distortions, so that the orthorhombic symmetry tended to regain its stability. The efficient occupancy of the smaller ions of V 5+ at the positions of Nb 5+ , leading to the lattice contraction and high localized strain, is represented by the variation in relative intensities and peak shifts to high 2θ values. The SEM experiment revealed that the best V 2 O 5 concentration produced good grain formation and densification and this ought to translate to increased dielectric and piezoelectric properties. There was a slight reduction in the grain uniformity due to excessive addition of V 2 O 5 proving that the optimum doping regime to achieve microstructural refinement was accomplished. Both Raman spectroscopy and FTIR revealed a variation in the local lattice dynamics as well as vibrational modes of the Nb-O bond, which demonstrates that the addition of vanadium alters the bonding environment and lattice symmetry. The depiction of changes in the electronic structure due to the introduction of defect states by the dopants was reflected in the UV-Vis spectrum with the band optical gap increasing steadily with V 2 O 5 concentration. Differential scanning calorimetry revealed changes in the phase transition temperatures on the addition of V 2 O 5 , implying that doping of LNN ceramics can change their thermal stability and lattice dynamics. Lower levels of doping reduced the Curie temperature slightly, whereas higher levels raised the transition, which implies more disorder and lattice stress. These results imply that V 2 O 5 can be employed as an effective dopant to tailor structural, microstructural, optical, vibrational and thermal properties of LNN ceramics. Regulated doping can offer a solution to optimizing piezoelectric ceramics based on LNN-based piezoelectric using lead-free materials by modulating lattice dynamics, improving densification, and creating a partial tetragonal phase to meet the current electronic and dielectric every day demands. Declarations Author Contribution Kamala: Conceptualization, Methodology, Software, Data curation, Writing- Original draft preparation. Ramalingeswara Rao: Visualization, Investigation. Software, Validation.: Ramesh: Writing- Reviewing and Editing, Supervision. References Devi DK, Manisha M, Venkatesham N, Edukondalu A, Raghupathi P, Prasad. BV (2026) J Mol Struct 1349(1):143603. https://doi.org/10.1016/j.molstruc.2025.143603 Wang W, Yuan X, Ma C, Tang F, Wang F, Cao Y (2015) Ceram Int 41:8377–8381. https://doi.org/10.1016/j.ceramint.2015.03.028 Yang W, Li P, Li F, Liu X, Shen B, Zhai J (2018) Ceram Int 45:2275–2280. https://doi.org/10.1016/j.ceramint.2018.10.141 Fu Z, Yang J, Lu P, Zhang L, Yao H, Xu F, Li Y (2017) Ceram Int 43:12893–12897. https://doi.org/10.1016/j.ceramint.2017.06.185 Xu F, Chen J, Lu Y, Zhang Q, Zhang Q, Zhou T, He Y (2018) Ceram Int 44:16745. https://doi.org/10.1016/j.ceramint.2018.06.104 Zhen Y, Li J-F, Wang K, Yan Y, Yu L (2011) Mater Sci Eng B 176:1110–1114. https://doi.org/10.1016/j.mseb.2011.05.051 Juárez RL, García FG, González RE (2011) J Alloy Comp 509:3837. https://doi.org/10.1016/j.jallcom.2010.12.103 Maiwa H (2016) Ferroelectrics 491:71–78. https://doi.org/10.1080/00150193.2015.1071610 Ichiki M, Zhang L, Maeda R, Eur J (2004) Ceram Soc 24:1693–1697. https://doi.org/10.1016/S0955-2219(03)00475-8 Li K, Li FL, Wang Y, Chan HLW (2011) Mater Chem Phys 131:320. https://doi.org/10.1016/j.matchemphys.2011.09.048 Wang Y, Damjanovic D, Klein N, Setter N (2008) J. Am. Ceram. Soc. 91 1962. https://doi.org/10.1111/j.1551-2916.2008.02392.x Izzuddin I, Jumali MHH, Zainuddin Z (2014) AIP Conf. Proc. 90–93. https://doi.org/10.1063/1.4895177 Zhang Y, Wang S, Zhang N, Wang A, Zhu Y, Cai F (2018) Ceram Int 8380. https://doi.org/10.1016/j.ceramint.2018.02.030 Gaur R, Dhingra A, Pal S, Singh KC (2015) J Alloy Comp 625:284–290. https://doi.org/10.1016/j.jallcom.2014.11.134 Wang H, Zuo R, Fu J, Liu Y (2011) J Alloy Comp 509:936–941. https://doi.org/10.1016/j.jallcom.2010.09.134 Chen C, Huang Y, Tan Y, Sheng Y (2016) J Alloy Comp 663:46–51. https://doi.org/10.1016/j.jallcom.2015.12.106 Saeri MR, Barzegar A, Ahmadi Moghadam H (2011) Ceram Int 37:3083–3087. https://doi.org/10.1016/j.ceramint.2011.05.044 Izzuddin I, Zainuddina Z, Janil NH (2019) Ceram Int 45:17204. https://doi.org/10.1016/j.ceramint.2019.05.275 Tzou WC, Chen YC, Cheng PS (2000) J Eur Ceram Soc 20:991. https://doi.org/10.1016/S0955-2219(99)00228-9 Huang CL, Chen YC (2003) J Eur Ceram Soc 23:167–173. https://doi.org/10.1016/S0955-2219(02)00086-9 Jean JH, Lee CH (2001) Jpn J Appl Phys 40:2232–2236. https://doi.org/10.1142/S0217984914500651 Zhai X, Wang H, Xu J, Yuan C, Zhang X, Zhou C, Liu X (2013) J Mater Sci: Mater Electron 24:687–691. https://doi.org/10.1007/s10854-012-0794-6 Amrita Nayak PK, Das SK, Patri (2020) AIP Conf. Proc. 2265 030205. https://doi.org/10.1063/5.0017556 Wu JG, Xiao DQ, Zhu JG, Yu PJ (2008) Appl Phys Lett 103:024102. https://doi.org/10.1063/1.2830997 Hao JG, Chu RQ, Zang GZ, Li GR (2009) J Alloys Compd 479:376–380. https://doi.org/10.1016/j.jallcom.2008.12.069 Ahart M, Somayazulu M, Cohen RE, Ganesh P, Dera P, Mao HK, Hemley RJ, Ren Y, Liermann P, Wu ZG (2008) Nature 451:545–552. 10.1038/nature06459 Xiao Y, Cheng D, Li G, Yin R, Li P, Gao Z (2025) J Electroceram. (in Press) https://doi.org/10.1007/s10832-025-00391-3 Kambale KR, Shroff S, Butee SP, Singh R, Kulkarni AR (2017) Ferroelectrics 518(1). https://doi.org/10.1080/00150193.2017.1360600 . )94 – 10 Navaneetha P, Kalyani B, Edukondalu A, Kumar NH, Vardhani CP (2024) M S Reddy Chem Pap 78:5851–5864. https://doi.org/10.1007/s11696-024-03489-0 Wang K, Li J (2012) J Adv Ceram 1:24–37. https://doi.org/10.1007/s40145-012-0003-3 Davis EA, Mott NF (1970) Philos Mag 22:903. https://doi.org/10.1080/14786437008221061 Tauc J, Menth A, Non-Cryst J (1972) Solids 8:569. https://doi.org/10.1016/0022-3093(72)90194-9 Chai QZ, Zhao XM, Chao XL, Yang ZP (2017) RSC Adv 7:28428. https://doi.org/10.1016/j.scriptamat.2018.05.022 Li Z, Gao L, Zhang C, Li F, Energy J, Storage 119 116336, Gio P, Bau T, Hoai N, Nam N (2025) J. Mater. Sci. Chem. Eng. 8 (2020) 1–11. 10.4236/msce.2020.87001 Hou J, Dai Z, Liu C, Yasui S, Cong Y (2023) Sh Gu J Alloys Compd 960:170639. https://doi.org/10.1016/j.jallcom.2023.170639 Urbach F (1953) Phys Rev 92:1324. https://doi.org/10.1103/PhysRev.92.1324 Edukondalu A, Rahman S, Siva Kumar K, Sreenivasu D (2014) Vib Spectrosc 71:91–97. https://doi.org/10.1016/j.vibspec.2014.01.010 Edukondalu A, Sathe V, Rahman S, Siva Kumar K (2014) Phys B 438:120–126. https://doi.org/10.1016/j.physb.2014.01.014 Silverstein RM, Webster FX (2005) Spectrometric Identification of Organic Compounds, 7th edn. Wiley Dai Y, Zhang X, Zhou G (2007) Appl Phys Lett 90(26):262903. https://doi.org/10.1063/1.2751607 Wang H, Luo H, Liang M, Ma H, Lv D, Qu F, Yin Y, Zhou Y, Zhang X, Zhao H, Miao Z (2025) Rare Met 44:4642–4656. https://doi.org/10.1007/s12598-025-03325-8 Chongtham Jiten K, Chandramani Singh (2017) J Mater Sci: Mater Electron 28:507–513. https://doi.org/10.1007/s10854-016-5551-9 Lubszczyk M, Brylewski T, Konieczny K, Kruk A (2024) J Alloys Compd 996:174814. https://doi.org/10.1016/j.jallcom.2024.174814 Marta Valášková K, Chrobáček B, Novosad S, Martynková (2018) Mater. Today Proc. 5(1) S96-S102. https://doi.org/10.1016/j.matpr.2018.05.062 Guo Y, Kakimoto K, Ohsato H (2004) Appl Phys Lett 85:4121. https://doi.org/10.1063/1.1813636 Saito Y, Takao H, Tani T, Nonoyama T, Takatori K, Homma T, Nagaya T, Nakamura M (2004) Nature 432:84. https://doi.org/10.1038/nature03028 Juang YD (2001) Solid State Commun 120:25. https://doi.org/10.1016/S0038-1098(01)00322-2 Dai SB, Juang YD, Hwang JS, Chu SY (2003) J Cryst Growth 257:316. https://doi.org/10.1016/S0022-0248(03)01475-1 Kirana K, Gangadhar V, Prasad G (2019) Mater. Today Proc. 11 (3) 971–979 https://doi.org/10.1016/j.matpr.2018.12.026 Cheng X (2014) Ceram Int 40(4):5771–5779. https://doi.org/10.1016/j.ceramint.2013.11.016 Kakimoto K (2005) Japanese J. Appl. Phys. 44(9S) 7064. 10.1143/JJAP.44.7064 Trodahl HJ (2008) Appl Phys Lett 4 93(26):262901. https://doi.org/10.1063/1.3056658 Kalyani B, Pujari N, Edukondalu A, Reddy MS, Vardhani CP (2022) Mater Lett 317:132128 Costa MM, Pires GFM, Terezo AJ, Grac MPF, Sombra ASB (2011) J Appl Phys 110:1–7 Parida BN, Padhee R, Choudhary RNP (2012) J Phys Chem Solid 73:713–719 Guo Y, Kakimoto K, Ohsato H (2004) Appl Phys Lett 85:4121 Badapanda T, Harichandan R, Kumar TB, Mishra SR, Anwar S (2016) J Mater Sci Mater Electron 27:7211–7221 Farea AMM, Kumar S, Batoo KM, Yousef A (2008) Alimuddin Phys B Condens Matter 403:684–701 Sahoo S, Das S, Mahapatra PK, Choudhary RNP (2018) Mater Chem Phys 216:158 Dhak P, Dhak D, Das M, Pramanik K, Pramanik P (2009) Mater Sci Eng B 164:165 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 03 Apr, 2026 Read the published version in Chemical Papers → Version 1 posted Editorial decision: Revision requested 20 Feb, 2026 Reviews received at journal 18 Feb, 2026 Reviewers agreed at journal 18 Feb, 2026 Reviews received at journal 17 Feb, 2026 Reviewers agreed at journal 17 Feb, 2026 Reviewers invited by journal 17 Feb, 2026 Editor assigned by journal 17 Feb, 2026 Submission checks completed at journal 16 Feb, 2026 First submitted to journal 14 Feb, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8881891","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":594509917,"identity":"33219987-238a-4441-97f3-09cd076a11f5","order_by":0,"name":"Kamala Sujani Dasary","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA1klEQVRIie3RMQrCMBSA4YDgVMkmrxTsFV4JBMEeJi51cai4OHoB6VrxCC6FQudCVkvXiksvIDh2tGn3JqNg/iUE3kcSQojN9oMBIYj9ilTtRGxMBEH3rAgaEqIIlmprQtxEZsdDJxmr79tPi8Sny3KaeBDFLBWS8+adQ3+x4HoT02QFDjJHyJA3VaaIwJeO0MdIWFrlnRHxyH4gHOmlMDvFTfu3ONGOQbMo1gJB/xaoZcGccBMkSZU/u1PoU09D+ubjZ8AwCdpx1awdFloaTdtsNtsf9gXgk0BYP8xxRQAAAABJRU5ErkJggg==","orcid":"","institution":"Andhra Christian College","correspondingAuthor":true,"prefix":"","firstName":"Kamala","middleName":"Sujani","lastName":"Dasary","suffix":""},{"id":594509921,"identity":"fa5d6e01-d577-4dbd-b178-a87098ccada9","order_by":1,"name":"K.V. Ramesh","email":"","orcid":"","institution":"GITAM school of Science, GITAM University","correspondingAuthor":false,"prefix":"","firstName":"K.V.","middleName":"","lastName":"Ramesh","suffix":""},{"id":594509923,"identity":"3d8d643e-72d9-4ba5-9a9b-7b647f5eec31","order_by":2,"name":"A. V. N. Ramalingeswara Rao","email":"","orcid":"","institution":"Naval Science and Technological Laboratory, Government of India","correspondingAuthor":false,"prefix":"","firstName":"A.","middleName":"V. N. Ramalingeswara","lastName":"Rao","suffix":""}],"badges":[],"createdAt":"2026-02-14 18:08:08","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8881891/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8881891/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s11696-026-04802-9","type":"published","date":"2026-04-03T15:58:23+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":103200958,"identity":"b5f07316-a7e1-45cf-8bae-0cd6762d3dc2","added_by":"auto","created_at":"2026-02-23 05:56:46","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":22073,"visible":true,"origin":"","legend":"\u003cp\u003eX-ray diffractograms of LNNV\u003csub\u003ex\u003c/sub\u003e (where x = 0, 1, 3, 5, and 9 mol%) ceramic system.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8881891/v1/ef84b548ff0150611b36b986.png"},{"id":103200957,"identity":"9162dbd5-60df-46dc-aa3b-e1057b4d8788","added_by":"auto","created_at":"2026-02-23 05:56:46","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":19072,"visible":true,"origin":"","legend":"\u003cp\u003eFine scan XRD patterns and peak separation in the range of 2θ from 31\u003csup\u003e◦\u003c/sup\u003e to 33\u003csup\u003e◦\u003c/sup\u003e.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8881891/v1/97f5cbd8e8e585022622d9f3.png"},{"id":103505054,"identity":"25873e0f-076c-40c3-8d9b-cba0586d7714","added_by":"auto","created_at":"2026-02-26 13:22:42","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":12114,"visible":true,"origin":"","legend":"\u003cp\u003eIntensity ratio of the two separated peaks in the range of 2θ from 31\u003csup\u003e◦\u003c/sup\u003e to 33\u003csup\u003e◦\u003c/sup\u003e.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8881891/v1/93b21ca45a709435eb3f2bca.png"},{"id":103505892,"identity":"2a04844d-8353-44e4-8c71-1bbb60e43798","added_by":"auto","created_at":"2026-02-26 13:33:23","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":475913,"visible":true,"origin":"","legend":"\u003cp\u003eSEM images of LNNV\u003csub\u003ex\u003c/sub\u003e\u0026nbsp; (x = 0,1,3,5 and 9 mol%) ceramics.\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8881891/v1/cddbc3125ea935c182925f41.jpg"},{"id":103200960,"identity":"cf1e37e8-5450-40a5-a6dc-73a6b36bd579","added_by":"auto","created_at":"2026-02-23 05:56:46","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":35030,"visible":true,"origin":"","legend":"\u003cp\u003e(a). MDSC thermogram of prepared ceramics.\u003c/p\u003e\n\u003cp\u003e(b). DSC thermogram and Curie temperature of LNN + xV\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e\u0026nbsp; (x = 0,1,3,5 and 9 mol%) ceramics.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-8881891/v1/cd87c0a4105c8032b385d39f.png"},{"id":103200962,"identity":"2395d540-45fb-4772-8142-cdef3a279861","added_by":"auto","created_at":"2026-02-23 05:56:46","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":24259,"visible":true,"origin":"","legend":"\u003cp\u003eOptical absorption spectrum of LNN + xV\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e ceramics.\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-8881891/v1/bee8f64d6b6050b1a36b6947.png"},{"id":103200966,"identity":"c0d93676-dd02-4474-9a61-393f4a9a6a58","added_by":"auto","created_at":"2026-02-23 05:56:46","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":48066,"visible":true,"origin":"","legend":"\u003cp\u003e(a)Tauc plots for the present system and (b) Direct optical band gap energy as a function of compositional parameter in present ceramics.\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-8881891/v1/3b44516d1ce8feb6542f6351.png"},{"id":103200963,"identity":"c25fd850-15d6-4278-8a74-80243a282704","added_by":"auto","created_at":"2026-02-23 05:56:46","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":20932,"visible":true,"origin":"","legend":"\u003cp\u003eInfrared spectra of LNNV\u003csub\u003ex\u003c/sub\u003e (where x = 0, 1, 3, 5, and 9 mol%) ceramic system.\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-8881891/v1/9c1658e7dbe37cd2be0e76b7.png"},{"id":103200965,"identity":"b7e89907-b7c8-40c9-8725-edf438aa6d59","added_by":"auto","created_at":"2026-02-23 05:56:46","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":16435,"visible":true,"origin":"","legend":"\u003cp\u003eDeconvoluted FTIR spectrum of LNNV\u003csub\u003e3\u003c/sub\u003e ceramic system.\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-8881891/v1/8059dc5910b8a8c52c839d96.png"},{"id":103505053,"identity":"e5f82698-1f74-4c9c-a46a-d17129c2a361","added_by":"auto","created_at":"2026-02-26 13:22:42","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":29124,"visible":true,"origin":"","legend":"\u003cp\u003eRaman spectra of LNNV\u003csub\u003ex\u003c/sub\u003e (where x = 0, 1, 3, 5, and 9 mol%) ceramic system.\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-8881891/v1/c93cd4cbf6f5ae8d8f216639.png"},{"id":103505417,"identity":"a6d20d0c-a3ee-4085-a778-9532833e6882","added_by":"auto","created_at":"2026-02-26 13:30:51","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":21407,"visible":true,"origin":"","legend":"\u003cp\u003eDeconvoluted Raman spectrum of LNNV\u003csub\u003e5\u003c/sub\u003e ceramic system.\u003c/p\u003e","description":"","filename":"11.png","url":"https://assets-eu.researchsquare.com/files/rs-8881891/v1/81bf60e6231ae95a8e56b15d.png"},{"id":103200968,"identity":"59afca35-7cd3-49a1-8b0c-c6aae95e110d","added_by":"auto","created_at":"2026-02-23 05:56:47","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":13016,"visible":true,"origin":"","legend":"\u003cp\u003eWave number of υ\u003csub\u003e1\u003c/sub\u003e stretching mode for LNN + xV\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5 \u003c/sub\u003eceramics.\u003c/p\u003e","description":"","filename":"12.png","url":"https://assets-eu.researchsquare.com/files/rs-8881891/v1/7cc21692e47eeee7136b558d.png"},{"id":106343732,"identity":"2c5552a7-3653-44f1-b891-2a3a5613c9f7","added_by":"auto","created_at":"2026-04-07 16:08:19","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1481288,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8881891/v1/a3f0dc7a-16f6-4c80-8833-17ab2fb88ea3.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Structural, Optical, and Vibrational Behavior of V₂O₅-Doped Li₀.₅Na₀.₅NbO₃ Ceramics","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eLead-based ceramics have been of keen interest as working material in recent decades due to their exceptional ferroelectric, dielectric and piezoelectric properties and are important in sensors, actuators as well as transducers [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Through research however, attention has shifted to development of environmentally friendly alternatives due to the toxicity of lead and its high impact on human health and the environment. lead-free ferroelectric ceramics that is friendly and has similar or better functionality. Their structural versatility, compositional versatility, and excellent electrical properties have made the perovskite-based systems the most promising of the many lead-free material families including tungsten-bronze, layered perovskite, and perovskite-type structures [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. In this regard, alternatives of lead zirconate titanate (PZT) have been well studied such as alkali niobates, barium titanate, modified alkali bismuth titanates, and materials with morphotropic phase boundaries (MPB) [\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eLithium sodium niobate (Li\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e; LNN) has become one of the most attractive lead-free ferroelectric systems in the alkali niobate family because of its large dielectric constant. Maximum anisotropy, low piezoelectric coefficients, minimal anisotropy, and chemical stability [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Li\u003csup\u003e+\u003c/sup\u003e is replaced by Na\u003csup\u003e+\u003c/sup\u003e in the perovskite lattice further enhancing polarization alignment due to the reduced ionic radius of Li\u003csup\u003e+\u003c/sup\u003e compared to Na\u003csup\u003e+\u003c/sup\u003e and this enhances ferroelectric properties. These advantages are notwithstanding the difficulty of producing stoichiometric and dense LNN ceramics because both Li\u003csub\u003e2\u003c/sub\u003eO and Na\u003csub\u003e2\u003c/sub\u003eO are highly volatile at high sintering temperatures and because of this, secondary phases are formed, densification is inadequate, and dielectric loss is elevated [\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The variables influence the reproducibility and electrical property of LNN ceramics. These difficulties have been overcome by multiple modern sintering techniques, such as spark plasma (SPS), hot isostatic (HIP), and template grain growth (TGG) to achieve a uniform microstructure and high density in LNN ceramics [\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. These methods have demonstrated to enhance piezoelectric and dielectric responses although tight control over processes and expensive equipment is needed rendering them not to be applicable to large-scale or industrial production. Another and more effective way of improving the densification and electrical properties is to incorporate the relevant dopants in the A- and/or B-sites of the perovskite lattice [\u003cspan additionalcitationids=\"CR18 CR19\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Different dopants alter the grain growth kinetics, the phase stability, and the conduction mechanism and enables the structural and functional properties to be tailored. As an example, it has been demonstrated that addition of CuO and ZnO can enhance the defect of formation and enhance other mechanical quality variables without affecting the piezoelectricity activity [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Likewise, it is possible to accomplish synergistic Improvements in the performance of Li-Na-Nb based ceramics through procedures that involve chemical modification and microstructural texturing [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eVanadium pentoxide (V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e) has currently been recognized as an effective sintering aid to electroceramics due to its low melting point ([?] 690 \u003csup\u003eo\u003c/sup\u003eC), which allows easier attainment of liquid-phase-aided sintering and promotes improved mass transport and densification [\u003cspan additionalcitationids=\"CR24\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. In perovskite ceramics, small amounts of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e can significantly reduce the sintering temperature, enhance the uniformity of the microstructure and enhance the dielectric and electrical conductivity characteristics. In addition, the more recent developments, such as cold-sintering-assisted sintering (CSAS) also showed the promise of controlling alkali volatilization and enhancing piezoelectric constants [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. It has been proposed that machine-learning-directed compositional optimization will be an effective approach to the development of high-performance lead-free piezoelectric ceramics in the future [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. This study focuses on the structural, thermal (DSC), optical, and vibrational properties of Li\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e (LNN) ceramics to which the V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e concentration was added (0, 1, 3, 5, and 7 weight percent). The 5 and 9 mol% were synthesized using the traditional solid-state reaction method. There is particular emphasis on the effect of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e doping on lattice dynamics, chemical bonding, optical band gap behaviors and grain boundary conduction mechanisms. All of them include differential scanning calorimetry (DSC), optical analysis (UV-Vis), spectral analysis (Raman), the Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and comprehensive characterization. The findings provide useful knowledge on the use of addition of vanadium to enhance the overall performance of lead-free LNN ceramics.\u003c/p\u003e"},{"header":"EPERIMETAL PROCEDURE","content":"\u003cp\u003eThe conventional solid-state reaction approach, which is a well-known method in the\u003c/p\u003e \u003cp\u003emanufacturing of perovskite-based oxide ceramics, was used to create lithium sodium niobate doped vanadium (LNNV) ceramics because it is thought to be dependable in achieving phase purity and compositional homogeneity.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eRaw materials and powder processing\u003c/h2\u003e \u003cp\u003eThe initial precursors were analytical-grade lithium carbonate (Li₂CO₃), sodium carbonate (Na₂CO₃), niobium pentoxide (Nb₂O₅), and vanadium pentoxide (V₂O₅) of high purity (99.95%).These compounds were weighed in their exact stoichiometric ratios of the nominal compositions Li₀.₅Na₀.₅NbO₃ + xV₂O₅ (x\u0026thinsp;=\u0026thinsp;0, 1, 3, 5, and 9 mol%). The powders were first dry-mixed and then ground manually in an agate mortar with a pestle for about 8 hours to a fine state to obtain a fine distribution of the particles and to ensure a minimum level of compositional inhomogeneity. The long grinding process was important in that close contact between the constituent oxides and carbonates was achieved, thereby facilitating solid-state diffusion during the later thermal treatment.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eCalcination, pre-sintering treatment\u003c/h3\u003e\n\u003cp\u003eThe homogenized powder mixtures were calcined at an ambient temperature of 1050\u0026deg;C in alumina crucibles over 5 hours. The aim of the calcification step was to begin solid-state diffusion, aid the breaking down of carbonates, and enhance the appearance of the perovskite KNN stage. The calcined powders had been reground with care to dispense agglomerates that had formed during heating and were then mixed with a few drops of an aqueous solution of polyvinyl alcohol (PVA) (a temporary binder) to facilitate pelletization.\u003c/p\u003e \u003cp\u003e \u003cb\u003ePellet fabrication, sintering.\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThe ready powders were molded into cylindrical milled pellets of 13 mm diameter and thickness of about 2 mm by use of a uniaxial hydraulic press at a pressure of 100 MPa. The green compacts were stacked on alumina plates that had been covered with platinum to eliminate contamination and sintered in air at 1100\u0026deg;C over a duration of 1.5 hrs. This sintering stage guaranteed sintering and an increase in the grain size, as well as the formation of a mechanically strong ceramic body. The pellets after sintering were polished on both sides with successively finer grades of silicon carbide (SiC) abrasive papers to form smooth, parallel, and uniform surfaces applicable to structural and electrical characterizations.\u003c/p\u003e\n\u003ch3\u003eDensity measurements\u003c/h3\u003e\n\u003cp\u003eThe theoretical densities of all the prepared compositions were determined using the corresponding molecular masses and crystallographic parameters. The Archimedes principle was used to determine the experimental bulk densities of the sintered specimens, with xylene being used as the immersion liquid. The sample codes, compositional details, theoretical densities calculated, and bulk densities measured experimentally are noted in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSample codes, compositional details, theoretical and bulk densities of the prepared samples\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eComposition\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eCode\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003eDensity (g/cc)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTheoretical\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eExperimental\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLi\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e+ 0V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLNNV\u003csub\u003e0\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.582\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.329\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLi\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e+ 1V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLNNV\u003csub\u003e1\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.606\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.386\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLi\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e+ 3V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLNNV\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.628\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.442\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLi\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e+ 5V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLNNV\u003csub\u003e5\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.643\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.507\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLi\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e+ 9V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLNNV\u003csub\u003e9\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.669\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.418\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\n\u003ch3\u003eMicrostructure and spectroscopy\u003c/h3\u003e\n\u003cp\u003eUtilizing RIGAKU D/Maz 2550V and BRUKER D8 Advance XRD equipment, the crystal structure of the material was determined using X-ray diffraction (XRD) with CuKα radiation. Microstructural research the grain size was measured using Scanning Electron Microscopy (SEM) with a JEOL JSM 5600 equipment with a resolution of 3.5 nm. A modulated differential The thermal properties of the ceramic samples were assessed using a scanning calorimeter (MDSC, TA Instruments Model 2910). Each sample was sealed in aluminum crucibles at a rate of approximately 15 mg each, and then subjected to a controlled heating rate of 10\u0026deg;C per minute. Throughout the experiments, dry nitrogen gas was used to cleanse the chamber and keep it in an inert atmosphere. The Curie temperature (T\u003csub\u003ec\u003c/sub\u003e) was calculated from the DSC plots using the onset point method, with a measurement uncertainty of \u0026plusmn;\u0026thinsp;1\u0026deg;C. A JASCO V670 UV-Vis spectrophotometer was used to acquire the room-temperature optical absorption spectra in the wavelength range of 200\u0026ndash;1000 nm. The instrument's software was then used to analyze the spectra. Samples were collected from polished ceramic surfaces to guarantee precise optical analysis. Furthermore, a Perkin-Elmer FT-IS was used to do Fourier Transform Infrared (FTIR) spectroscopy. Infrared spectra in the range of 400 to 1500 cm\u003csup\u003e-1\u003c/sup\u003e were captured by analyzing the samples using a model 1605 spectrometer. A Jobin-Yvon Horiba Raman spectrometer was used to The LABRAM HR-800 spectrometer, which had a confocal microscope, was also used to make Raman measurements. A microscope and an excitation source were used for the excitation. An Ar\u003csup\u003e+\u003c/sup\u003e laser beam with a wavelength of 488 nm that produces high spectral resolution and accurate Raman shifts.\u003c/p\u003e"},{"header":"RESULTS AND DISCUSSIONS","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eX-ray diffraction\u003c/h2\u003e \u003cp\u003eThe X-ray diffraction (XRD) spectrums of Li\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e ceramics with varied percentages of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e (x\u0026thinsp;=\u0026thinsp;0, 1, 3, 5, and 9 mol) are shown. Figure\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows that all compositions have the clear evidence of diffraction peaks that can be attributed to the presence of a perovskite-based orthorhombic structure, which is consistent with the regular JCPDS card No. 32\u0026ndash;0822 [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e addition does not cause the appearance of other secondary or impurity phases, meaning that the dopant and the host lattice were completely compatible in chemistry and there was a complete reaction between the two, exclusively in the solid state. Diffraction peaks positions are slightly varied and the relative peak intensities change when the concentration of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e is increased and this indicates that there are some small structural changes that occur when Vanadium is added. The 2θ range of 32\u003csup\u003eo\u003c/sup\u003e-33\u003csup\u003eo\u003c/sup\u003e, and especially, is distinctly separated into two different reflections at the values of 32.4\u003csup\u003eo\u003c/sup\u003e and 32.9\u003csup\u003eo\u003c/sup\u003e, as observed in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. This bifurcation is an indication of both tetragonal and orthorhombic phases that exist thus V\u003csup\u003e5+\u003c/sup\u003e doping induces local structural changes in the perovskite structure. To determine this structural change, the intensity ratio (I\u003csub\u003e1\u003c/sub\u003e/I\u003csub\u003e2\u003c/sub\u003e) of the split peaks in the 32\u003csup\u003eo\u003c/sup\u003e-33\u003csup\u003eo\u003c/sup\u003e region was calculated (see Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Even the undoped sample (x\u0026thinsp;=\u0026thinsp;0) retains a highly orthorhombic structure and a rather low I\u003csub\u003e1\u003c/sub\u003e/I\u003csub\u003e2\u003c/sub\u003e ratio. The ratio rises tremendously when doped with 1 mol% V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e, showing a higher percentage of the tetragonal phase. The tetragonal phase is maximized at the maximum value of I\u003csub\u003e1\u003c/sub\u003e/I\u003csub\u003e2\u003c/sub\u003e which is at x\u0026thinsp;=\u0026thinsp;1 mol%. The ratio gradually decreases before this concentration (x\u0026thinsp;\u0026ge;\u0026thinsp;3 mol%), which implies that a higher doping concentration results in a restoration of orthorhombic symmetry.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThese findings can be explained by the ionic size mismatch between the replacing cation V\u003csup\u003e5+\u003c/sup\u003e (0.59 A) and the host Nb\u003csup\u003e5+\u003c/sup\u003e ion (0.69 A). Internal chemical pressure and local stress that the substitution of the B-site with smaller V\u003csup\u003e5+\u003c/sup\u003e ions causes destabilizes the orthorhombic lattice and promotes the formation of a more symmetrical tetragonal phase at reduced concentrations. At greater concentrations of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e, however, over substitution causes a greater lattice distortion and relaxation of stress, which re-forms the orthorhombic ordering through structural re-equilibration [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Also, the systematic shift of the main diffraction peaks to higher 2θ values with increase in V concentration is indicative of a reduction in lattice parameters which is consistent with the introduction of smaller V\u003csup\u003e5+\u003c/sup\u003e ions into the Nb\u003csup\u003e5+\u003c/sup\u003e sites resulted in a lattice contraction. Besides modifying the dimensions of the unit cell, this contraction can also affect the crystal symmetry, bonding environment and stability of the perovskite phase. According to the XRD results, it can be concluded that V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e doping affects the crystal structure of Li\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e ceramics on a large scale even with quite a small percentage of doping (x\u0026thinsp;\u0026asymp;\u0026thinsp;1%). More concentrations cause an increase in lattice strain and re-establishment of the orthorhombic phase, and 1 mol% causes a partial transition to tetragonal symmetry. To control the microstructural and functional properties of LNN-based lead-free piezoelectric ceramics, such controlled structural change with V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e doping is crucial [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eScanning Electron Microscopy (SEM)\u003c/h3\u003e\n\u003cp\u003eThe surface morphology of the sintered Li\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e + x mol% V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e ceramics (x\u0026thinsp;=\u0026thinsp;0, 1, 3, 5, 9) was studied using scanning electron microscopy. (SEM), as depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. The polycrystalline microstructure of all the samples, which have distinct grain boundaries, favors the creation of a single-phase perovskite matrix. Vanadium oxide has a major effect on grain shape, size, and porosity, indicating that it is essential for the densification process. The undoped LNN sample (x\u0026thinsp;=\u0026thinsp;0) contains a small number of intergranular pores and comparatively small and equiaxed grains of the sample with distinct grain boundaries. Its average grain size is 0.9\u0026ndash;1.2 mm, which means that the grain growth is suppressible in the sintering environment. Alkali elements are unstable during sintering, limiting densification and resulting in low porosity in alkali niobate-based ceramics, as seen in this morphology [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. Adding 1 mole percent alters the grain size to 1.3\u0026ndash;1.7 micrometers, and the microstructure narrows down. This improvement can be explained by the liquid nature of the sintering of V₂O₅ that melts at a low temperature (approximately 690\u0026deg;C) and allows viscous flow and diffusion along grain boundaries [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. The reduction in porosity and smooth grain boundaries translates to higher grain boundary mobility and effective diffusion of ions during the sintering process.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe microstructure of the 3 mol percent V₂O₅ sample had a uniform distribution of well-faceted grains ranging between 1.9 and 2.3 mm, thus indicating optimal densification. The grains appear to be denser, and they have fewer pores and no visible secondary phases. The perfect level of V₂O₅ is also a powerful sintering aid in which LNN grain rearrangement and merging can occur without creating any adverse impacts. Separative action of the liquid phase is brought about by [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. This improvement in the uniformity of the microstructure is advantageous towards the realization of uniform electrical and dielectric values. Above the level of higher concentrations of V₂O₅ (5 mol%), the particles are irregular and even somewhat extended, which shows the local melting or agglomeration. The average grain size is between 2.0 and 2.4 mm, and there are a few areas of glassy intergranular between the grain boundaries. Such glassy areas are presumably due to the segregation of surplus V₂O₅ at the grain boundaries during the sintering process that leads to partial wetting of the grain boundaries [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. Although the densification is high, the presence of a second phase may introduce interfacial potential barriers that hinder the charge transfer and dielectric relaxation. Which inhibit carrier cross-grain flow. The 9 mol percent V₂O₅ blend is irregular in the structure of the grains and melted spots on the surface. The grain boundaries are smeared (due to the constant liquid-like state of the excessive V₂O₅). The overall microstructural uniformity is damaged despite the average grain size, which is 2.5\u0026ndash;2.9 mm. Over-sintering results in excessive production of liquid phase and consequently vanadium-rich segregations and secondary phases, as these features indicate. This can cause local lattice distortion and increased oxygen vacancies as well as potential changes in the valence states (V\u003csup\u003e5+\u003c/sup\u003e \u0026rarr; V\u003csup\u003e4+\u003c/sup\u003e) that not only improve electrical properties but also increase dielectric loss. Based on SEM data, V₂O₅ is an aid in sintering and a structural modulator. Moderate doping (1\u0026ndash;3mol%) enhances grain growth, densification, and uniformity, while greater doping concentrations (\u0026ge;\u0026thinsp;5 mol%) cause microstructural heterogeneity and liquid-phase production. The observed changes in dielectric relaxation behavior and a.c. conductivity with increasing V₂O₅ concentration are well correlated with the microstructural evolution, which shows an increase in densification and a decrease in Increasing grain boundary resistance improves conduction pathways [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e].\u003c/p\u003e\n\u003ch3\u003eDifferential scanning calorimetry\u003c/h3\u003e\n\u003cp\u003eThe thermal behavior of current ceramics with varying quantities of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e addition was studied using differential scanning calorimetry (DSC) in order to comprehend the effect of the integration of vanadium into the ferroelectric-paraelectric phase shifts. Figure\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e5\u003c/span\u003e(a and b) displays the DSC thermograms for all formulations. DSC analysis is a trustworthy method for identifying thermal occurrences related to structural phase transitions in perovskite-type niobate ceramics, which have a direct impact on their ferroelectric and dielectric properties. The DSC curve of the pure LNN sample (x\u0026thinsp;=\u0026thinsp;0 mol%) shows two clear endothermic peaks. The initial one, a sharp peak at around 420\u0026deg;C, denotes the ferroelectric phase shift between the orthorhombic and tetragonal (O\u0026ndash;T) phases. The second, wider endothermic characteristic, which occurs between 480 and 500\u0026deg;C, corresponds to the tetragonal-to-cubic (T-C) transition, which is linked to the shift to the paraelectric state. These two clearly defined transitions are typical of alkali niobate systems and point to a high degree of long-range ferroelectric order within the undoped LNN matrix.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAfter the introduction of 1 mol% V₂O₅, both transition peaks remain, but the O\u0026ndash;T transition moves somewhat towards higher temperatures (between 430 and 435\u0026deg;C), while the The T\u0026ndash;C transition still occurs between 490 and 500\u0026deg;C, with only a slight sharpening. This behavior indicates greater structural stiffness of the lattice and improved thermal stability of the ferroelectric phase. In the perovskite lattice, the replacement of Nb\u003csup\u003e5+\u003c/sup\u003e ions (0.69 \u0026Aring;) with smaller V\u003csup\u003e5+\u003c/sup\u003e ions (0.59 \u0026Aring;) at the B-site creates chemical pressure, which lowers octahedral distortion and increases the strength of the Nb/V\u0026ndash;O bond. As a result, more thermal energy is needed for the O\u0026ndash;T phase transition. This stabilization effect is supported by Raman and FTIR experiments, which demonstrate that the vibrational bands have narrowed and shifted towards the blue range, while the anharmonicity of the lattice has decreased and interactions between the metals and oxygen have strengthened. A slight decline in temperature is observed as the concentration of vanadium increases to 3 mol%. The expansion of the thermal event indicates the initiation of the diffuse phase transition (DPT) behavior. Because of the imbalance of charges, the addition of more V\u003csup\u003e5+\u003c/sup\u003e ions results in the strain of the lattice and oxygen vacuity, which provides local structural disruption. These defects promote a relaxor-like behavior, decrease long-range interaction between dipoles, and disrupt the coherence of the ferroelectric domains[\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe wide, flat peaks in the DSC thermograms manifest this compositional deformity. The DSC curve of the 5 mol percent V₂O₅-doped sample reveals only a single broad endothermic peak at 470\u0026ndash;480\u0026deg;C, and no clear distinction between the O-T and T-C transitions is apparent. Such a combination of transitions implies the formation of an intermediate or mixed-phase space where orthorhombic, tetragonal, and pseudo-cubic domains can coexist over a large temperature range. It may be explained by excess V incorporation resulting in local non-centrosymmetric distortions and enhanced microstrain. The diffuse and smeared nature of the transition suggests a gradual and not abrupt phase transition development, as is expected of the evolution of compositional heterogeneity within the lattice. The DSC thermogram of 9 mol% V₂O₅ has a faint and broad hump at approximately 480\u0026deg;C, but no distinct endothermic peaks. The partial amorphization of the LNN matrix and the absence of a distinct phase change indicate significant structural disorder. Comprehensive V\u003csup\u003e5+\u003c/sup\u003e doping leads to serious lattice distortion, the formation of oxygen vacancies, and the disruption of octahedral bonding. Those effects inhibit ferroelectric ordering and trigger relaxor-type behavior, where there are only local polar regions with no long-range order. The findings agree with Raman and XRD data that show peak broadening and band blurring at greater doping levels, supporting a decrease in crystallinity and an increase in internal stress. Due to the following reasons, the DSC analysis demonstrates unequivocally that a small amount of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e doping (x\u0026thinsp;=\u0026thinsp;1 mol%) improves lattice stability and raises the temperature of the ferroelectric phase transition: decreased lattice distortion and the reinforcement of Nb/V\u0026ndash;O connections. However, higher doping concentrations (x\u0026thinsp;\u0026ge;\u0026thinsp;3 mol%) cause chemical and structural disorder, which results in the suppression of ferroelectric\u0026ndash;paraelectric transformations and broad, diffuse, or fused thermal transitions[\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. These results show that the phase behavior of LNN\u0026thinsp;+\u0026thinsp;V₂O₅ ceramics may be tuned based on their composition, allowing for the strategic optimization of temperature stability and dielectric characteristics for piezoelectric actuators, transducers, and sensors.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eOptical Properties\u003c/h2\u003e \u003cp\u003eUV-visible spectroscopy was employed to investigate the optical properties of Li\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e + x mol% V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e ceramics for x values of 0, 1, 3, 5, and 9, as seen in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e6\u003c/span\u003e, within the wavelength range of 200 to 1000 nm. The influence of V₂O₅ incorporation on the electronic structure and optical transitions of the system is evidenced by the broad absorption edges in the spectra, which systematically vary with increasing vanadium concentration. As the quantity of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e increases from 0 to 9 mol%, the optical transmittance significantly decreases. The LNN\u0026thinsp;+\u0026thinsp;3 mol% V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e combination demonstrates the highest transmittance, approximately 60% within the visible spectrum, while the pure LNN sample exhibits moderate transparency. This result signifies that the optical clarity and scattering losses are enhanced at this doping dose. The enhancement in transmittance at intermediate V₂O₅ concentrations is primarily attributed to the reduction in surface porosity, the finer grain size (~\u0026thinsp;400 nm), and the augmentation of V₂O₅'s fluxing action during sintering [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e], which induces crystallinity. Higher amounts of V₂O₅ (\u0026ge;\u0026thinsp;5 mol%) cause the microstructure to become denser with fewer grain boundaries, which reduces light scattering and improves transmission through the bulk. However, at higher V₂O₅ levels, the transmission decreases noticeably, suggesting increased absorption that may result from the introduction of localized electronic levels within the band gap due to the creation of vanadium-related defect states or secondary glassy phases [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. To analyze the optical absorption behavior quantitatively, the absorption coefficient (α) was derived from the absorbance data using a formula. The dependence of the absorption coefficient near the fundamental edge follows the Tauc relation [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e(αhν)\u0026thinsp;=\u0026thinsp;B(hν\u0026thinsp;\u0026minus;\u0026thinsp;E\u003csub\u003eg\u003c/sub\u003e)\u003csup\u003en\u003c/sup\u003e (2)\u003c/p\u003e \u003cp\u003ewhere B is a constant, hν is the photon energy, Eg is the optical band gap, and n characterizes the nature of the electronic transition (n\u0026thinsp;=\u0026thinsp;1/2 for direct allowed and n\u0026thinsp;=\u0026thinsp;2 for indirect allowed transitions). Both direct and indirect optical band gaps were determined by plotting (αhν)\u0026sup2; and (αhν)\u0026sup1;ᐟ\u0026sup2; versus photon energy (hν) and extrapolating the linear portions to the energy axis, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e7\u003c/span\u003e(a, b). The estimated indirect band gap (Eg, indirect) values range from 3.13 eV (x\u0026thinsp;=\u0026thinsp;0) to 3.01 eV (x\u0026thinsp;=\u0026thinsp;9), whereas the direct band gap (Eg, direct) values vary from 3.39 eV for the undoped sample to 3.26 eV for the 9 mol% V₂O₅ composition. The observed redshift of the absorption edge with increasing vanadium concentration indicates a band gap narrowing effect. This reduction in band gap energy is ascribed to several factors. First, V⁵⁺ ions partially replace Nb⁵⁺ at the B-site because their ionic radii are similar (V⁵⁺ = 0.59 \u0026Aring;, Nb⁵⁺ = 0.64 \u0026Aring;). V-O states are localized right below the conduction band. These states are shallow levels of donor so that they can be excited electronically at lower photon energy. Secondly, combined valence states (V\u003csup\u003e5+\u003c/sup\u003e/V\u003csup\u003e4+\u003c/sup\u003e) and associated oxygen vacancies result in localized defect levels, which enhance sub-bandgap absorption. The overlap of localized states with the tail of the conduction band increases with increased concentration of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e and decreases the effective band gap a common phenomenon in oxide systems with transition metals [\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e]. Moreover, substitution of Nb\u003csup\u003e5+\u003c/sup\u003e by V\u003csup\u003e5+\u003c/sup\u003e leads to structural variations that bring about local variations in the symmetry of NbO\u003csub\u003e6\u003c/sub\u003e octahedra and the orbital hybridization of the V-O and Nb-O bonds. The interaction of the vanadium d-orbitals with the oxygen p-orbitals causes band tailing at the absorption edge which leads to the redshift in the optical spectra [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. The production of defect-generated energy levels within the forbidden gap region is also enhanced by the rise in absorption intensity with the rise in the concentration of vanadium. The value of optical band gaps of direct transitions is 3.155\u0026ndash;3.398 eV, and those of indirect transitions are 3.018\u0026ndash;3.23 eV, which are consistent with the values, with previously demonstrated values of the ion-doped perovskite oxides and alkali niobate-based ferroelectrics. The increased transmittance observed in the samples with lower content of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e is attributed to the fact that larger band gap is usually associated with increased optical transparency and reduced absorption. A decrease in the size of the gap with increased levels of doping is a sign of increased electronic polarizability and an increase in the concentration of charge carriers, and it can also affect the previously mentioned dielectric and conductive properties. The UV\u0026ndash;Vis analysis confirms that V₂O₅ incorporation modifies the electronic band structure of LNN ceramics by introducing defect-related states and structural distortions. Moderate V₂O₅ addition (1\u0026ndash;3 mol%) optimizes the balance between transparency and conductivity, whereas higher concentrations (\u0026ge;\u0026thinsp;5 mol%) promote defect-level formation and increased optical absorption.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe magnitude of structural disorder and flaw density in the material can be deduced further from the tail of the absorption edge. This area adheres to the Urbach empirical equation [\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e]. The formula for the absorption coefficient as a function of photon energy is α(hν) = α₀ exp(hν/Eu). Here, α₀ is a constant, and E\u003csub\u003eu\u003c/sub\u003e is the Urbach energy, which reflects the width of the localized tail states inside the band gap. As illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e8\u003c/span\u003e, the E\u003csub\u003eu\u003c/sub\u003e values were derived from the slope of the linear section of the graph between ln(α) and hν. The expected variation in E values increased a bit with the quantity of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e added (i.e., increased disorder and defect generation), with a range of 0.29 eV (x\u0026thinsp;=\u0026thinsp;0) up to 0.38 eV ( x\u0026thinsp;=\u0026thinsp;9 mol%). This enhancement of E could be attributed to the enhanced oxygen vacuity concentration and local lattice distortions generated by V\u003csup\u003e5+\u003c/sup\u003e/ V\u003csup\u003e4+\u003c/sup\u003e ions. The forbidden band caused by the coexistence of these defect states within the effective optical band gap lowers the effective optical band gap. The negative dependence that appears between the band gap between E and E9 and the disorder is in agreement with the previously observed correlated barrier hopping and band tailing phenomena on other oxide systems doped with vanadium [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e, \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e]. Thus, the concomitant reduction in the band gap and the increase in the Urbach energy are indicative of the formation of fault-generated localized states, which are the cause of observed optical redshift and increased absorption of highly-doped samples.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eSpectroscopic Studies\u003c/h2\u003e \u003cp\u003eStructural changes and vibrational behavior of Li\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e (LNN) ceramics caused by V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e replacement was studied by Fourier Transform Infrared (FTIR) and Raman spectroscopies. These methods are quite susceptible to variations in the local bonding environment, especially in complex perovskites that have the ability of oxygen octahedral distortions and cationic replacements that can affect the phonon structure and lattice symmetry.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eFTIR spectra\u003c/h2\u003e \u003cp\u003eThe infrared absorption spectra of Li₀.₅Na₀.₅NbO₃ + xV₂O₅ ceramics (x\u0026thinsp;=\u0026thinsp;0, 1, 3, 5, and 9 mol%) were recorded in the spectral range of 400\u0026ndash;4500 cm⁻\u0026sup1;. The normalized FTIR spectra, shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e8\u003c/span\u003e, show significant absorption characteristics between 400 and 1600 cm⁻\u0026sup1;, primarily caused by metal-oxygen vibrations of the niobate and vanadate networks. The spectra are limited to the 400\u0026ndash;1800 cm⁻\u0026sup1; range for clarity. Each spectrum was deconvolved using Gaussian fitting with 8\u0026ndash;10 components, as shown for the 3 mol% V₂O₅-doped sample in Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e9\u003c/span\u003e. Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e lists the deconvolved peak locations along with their respective assignments. The undoped Li₀.₅Na₀.₅NbO₃ sample displays distinctive absorption bands at around 400, 517, 583, and 649 cm⁻\u0026sup1;. These are thought to be caused by the intrinsic vibrations of NbO₆ octahedra, which are common in perovskite-type niobates. The 400 cm⁻\u0026sup1; band is associated with Nb-O bending, the 517 cm⁻\u0026sup1; band with O-Nb-O deformation, the 583 cm⁻\u0026sup1; band with symmetric Nb-O stretching, and the 649 cm⁻\u0026sup1; band with asymmetric Nb-O stretching oscillations. These characteristics corroborate the presence of Nb⁵⁺ ions in octahedral coordination within the ABO₃ lattice framework [\u003cspan additionalcitationids=\"CR48\" citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e]. New absorption bands appear at around 765, 829, and 1060 cm⁻\u0026sup1; when V₂O₅ is added, which are not present in the undoped material. These are assigned to vanadium-oxygen vibrations: the 765 cm⁻\u0026sup1; band to V\u0026ndash;O\u0026ndash;V bending or symmetric stretching, the 829 cm⁻\u0026sup1; band to terminal V\u0026thinsp;=\u0026thinsp;O stretching, and the asymmetric V\u0026thinsp;=\u0026thinsp;O stretch at the 1060 cm⁻\u0026sup1; band. The formation of vanadate (VO₄ or VO₅) units is indicated by the emergence of these new modes, indicating either a partial substitution of Nb⁵⁺ by V⁵⁺ or the development of vanadium-rich secondary phases. Such replacement is structurally conceivable given that V⁵⁺ (0.59 \u0026Aring;) and Nb⁵⁺ (0.64 \u0026Aring;) have similar ionic radii and oxidation states [\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e]. Furthermore, as the amount of V₂O₅ increases, local lattice distortion is indicated by the somewhat altered frequency and intensity of the Nb\u0026ndash;O stretching and bending bands (517\u0026ndash;649 cm⁻\u0026sup1;). These variations in symmetry may lead to the potential formation of oxygen vacancies or defect dipoles. These effects change the polarizability and bonding strength of the NbO₆ network, which aligns with the behavior seen in other perovskite systems modified by V₂O₅ [\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e]. In the low-frequency range (below 400 cm⁻\u0026sup1;), there may be modest contributions from Li-O and Na-O lattice oscillations or their interaction with Nb-O modes. The overall symmetry of the lattice is affected by the differing ionic radii of the Li⁺ and Na⁺ ions (Li⁺ \u0026asymp; 1.64 \u0026Aring;; Na⁺ \u0026asymp; 1.39 \u0026Aring;), even if these ions are just moderately infrared active and dynamic inside the perovskite structure [\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e]. The broad bands around 1520 cm⁻\u0026sup1; and 1650 cm⁻\u0026sup1; are attributed to the stretching of trace organic residues and the bending of adsorbed water's H\u0026ndash;O\u0026ndash;H bonds, respectively. Their intensity may somewhat rise with increased V₂O₅ concentration, maybe as a result of improved surface reactivity and porosity, which facilitate moisture absorption [\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e]. In general, the gradual changes in FTIR spectra with increasing V₂O₅ concentration represent a combination of (i) NbO₆ octahedral distortion, (ii) the production of V\u0026ndash;O\u0026ndash;V and V\u0026thinsp;=\u0026thinsp;O units, and (iii) small lattice disturbances caused by the effects of A-site cations. As a result, V₂O₅ functions as both a structural modifier and a sintering aid, changing the local bonding environment that may have an impact on the dielectric and electrical characteristics of the ceramics [\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBand positions and corresponding vibrational assignments of FTIR and Raman spectra for all ceramic compositions\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eband position (cm⁻\u0026sup1;)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSpectroscopic technique\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eVibrational assignment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eEffect of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e mol%\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e150\u0026ndash;180\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRaman\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTranslational mode of A-site cations (Li⁺/Na⁺)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eExternal vibration of alkali ions in perovskite lattice\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBelow 400\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFTIR/ Raman\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLattice and translational vibrations\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCollective vibrations of perovskite framework involving A- and B-site cations\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e240\u0026ndash;270\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRaman\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eO\u0026ndash;Nb\u0026ndash;O bending vibration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSensitive to local lattice distortion and oxygen positional disorder\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e330\u0026ndash;360\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRaman\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOctahedral tilt / O\u0026ndash;B\u0026ndash;O bending\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eReflects structural distortion and tilting of NbO\u003csub\u003e6\u003c/sub\u003e units\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e430\u0026ndash;470\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFTIR/ Raman\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSymmetric Nb\u0026ndash;O stretching / lattice vibration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eRepresents A\u0026ndash;O\u0026ndash;B type vibration and perovskite lattice mode\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e520\u0026ndash;560\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFTIR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eO\u0026ndash;Nb\u0026ndash;O bending vibration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eInternal deformation mode of BO\u003csub\u003e6\u003c/sub\u003e octahedra\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e600\u0026ndash;650\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFTIR/Raman\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNb\u0026ndash;O stretching vibration in NbO₆ octahedra\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eStrong characteristic band of orthorhombic perovskite structure\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e710\u0026ndash;730\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRaman\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNb\u0026ndash;O\u0026ndash;V stretching mode\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eConfirms partial substitution of V\u003csup\u003e5+\u003c/sup\u003e at B site in the perovskite lattice\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e780\u0026ndash;810\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFTIR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNb\u0026ndash;O\u0026ndash;V / Nb\u0026ndash;O\u0026ndash;Nb asymmetric stretching\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eArises from corner-sharing BO\u003csub\u003e6\u003c/sub\u003e octahedra; slightly shifts with V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003econtent\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e850\u0026ndash;890\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFTIR/Raman\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eV\u0026thinsp;=\u0026thinsp;O stretching vibration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCharacteristic of terminal vanadyl (V\u003cb\u003e⁵\u003c/b\u003e⁺\u0026ndash;O) bonds; indicates V₂O₅ incorporation or surface segregation\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e950\u0026ndash;980\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRaman\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eShort V\u0026thinsp;=\u0026thinsp;O terminal bond stretching\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eEvidence of localized vanadyl species or minor V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e phase at high doping\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1630\u0026ndash;1650\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFTIR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eH\u0026ndash;O\u0026ndash;H bending vibration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePhysically adsorbed water molecules on ceramic grains\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3450\u0026ndash;3550\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFTIR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eO\u0026ndash;H stretching vibration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eDue to adsorbed surface hydroxyl groups and moisture\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eRaman spectra\u003c/h2\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig11\" class=\"InternalRef\"\u003e10\u003c/span\u003e shows the room-temperature Raman spectrum of Li\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e + xV\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e (x\u0026thinsp;=\u0026thinsp;0, 1, 3, 5, and 9 mol%) ceramics. The deconvolution of each spectrum was done with six to seven Gaussian functions to ascertain correctly the position and relative intensity of the Raman bands. Figure\u0026nbsp;\u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e11\u003c/span\u003e provides an example of this deconvolution of the V₂O₅-doped 5 mol% sample. Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e lists the deconvolved peak locations along with their respective assignments. The presence of the observed Raman bands can be broadly grouped into three areas, namely, the low-frequency (less than 300 cm⁻\u0026sup1;), mid-frequency (250\u0026ndash;650 cm⁻\u0026sup1;), and high-frequency (800\u0026ndash;900 cm⁻\u0026sup1;) regions. Table\u0026nbsp;3 presents the local maxima and their associated positions. A number of sharp Raman modes can be observed in the undoped Li\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e (LNN) sample, which is an indication of an ordered orthorhombic (Amm2) symmetry. The vibrations with modes close to 130\u0026ndash;138 cm⁻\u0026sup1; are attributed to the translational vibration of A-site cations (Li⁺/Na⁺) with the NbO₆ octahedral structure [\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e, \u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e]. As the content of V₂O₅ rises, there is a slight but appreciable movement of these low frequencies in the form of a shift. For the 5 mol% sample, the translational peak is observed at 155 cm⁻\u0026sup1;, while for the 9 mol% doping, it shifts to 145 cm⁻\u0026sup1;, and then it is observed again at 152 cm⁻\u0026sup1; for a higher concentration. This difference is attributed to the variation in A-site dynamics, as well as changes in local strain, which are brought about by lattice distortion and mass fluctuations with the incorporation of vanadium [\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e]. At middle frequency (250\u0026ndash;650 cm⁻\u0026sup1;), several bands are observed at approximately 213, 248, 270, 560, and 620 cm⁻\u0026sup1;. These are credited to Nb-O bending (υ\u003csub\u003e4\u003c/sub\u003e, υ\u003csub\u003e5\u003c/sub\u003e, υ\u003csub\u003e6\u003c/sub\u003e) and asymmetric stretching vibrations of NbO\u003csub\u003e6\u003c/sub\u003e octahedra [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The 256 cm⁻\u0026sup1; band is near the Nb-O bending (υ₅) mode that is sensitive to lattice distortion. This mode is split at increased V₂O₅ doping, and a second peak appears between 250 and 300 cm⁻\u0026sup1;, indicating that there are two different NbO₆ environments or both orthorhombic and tetragonal phases. This finding conforms to the XRD results, which indicated a gradual change of orthorhombic structure to tetragonal structure [\u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e58\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe symmetrical octahedra stretch (υ\u003csub\u003e1\u003c/sub\u003e) mode of the NbO\u003csub\u003e6\u003c/sub\u003e is attributed to a strong Raman band at 615 cm⁻\u0026sup1;. This mode is subjected to systematic frequency shift and broadening with an increase in the concentration of V₂O₅. The transition to higher wavenumbers indicates the reduction of the length of Nb-O bonds due to the partial replacement of Nb⁵⁺ (ionic radius 0.64 \u0026Aring;) by the smaller V⁵⁺ ion (0.54 \u0026Aring;), which caused the strengthening of bonds and the decrease in lattice symmetry [\u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e]. The development of the υ\u003csub\u003e1\u003c/sub\u003e band position with the increase in vanadium content is given in Fig.\u0026nbsp;\u003cspan refid=\"Fig13\" class=\"InternalRef\"\u003e12\u003c/span\u003e, which proves the lattice contraction due to the V doping. Another band is observed at the high frequency (800\u0026ndash;900 cm⁻\u0026sup1;) at about 860 cm⁻\u0026sup1; in samples with V₂O₅, but not in the undoped LNN. It is the highest peak because of the V\u0026thinsp;=\u0026thinsp;O terminal stretching vibration, which is the result of tetrahedral or distorted octahedral units of vanadate (VO₄/VO₅) [\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e, \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e]. The onset of this mode is a pointer to successful vanadium incorporation by the LNN lattice, either by replacing the Nb site or by occupying interstitial positions. This high-frequency band also indicates that the partial redistribution of charges and the possible creation of mixed-valence species of V⁴⁺/V⁵⁺ may occur and affect the electronic processes in conductivity and polarization through defects. The half maximum and full width (FWHM) of υ\u003csub\u003e1\u003c/sub\u003e and υ\u003csub\u003e5\u003c/sub\u003e modes have a positive relation with the quantity of vanadium, indicating the presence of more phonon scattering caused by local lattice disorder. This expansion implies increased dynamic coupling of octahedrals to a greater extent of structural distortion, particularly in the region of the morphotropic phase boundary (MPB), where compositional inhomogeneity is intense [\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e]. The general trend in the Raman data shows that the addition of V₂O₅ changes the vibrational dynamics of both the A-site and B-site, adds new V-O-related modes, and causes the structural transformation of the orthorhombic to tetragonal symmetry. The observed increase in the dielectric, piezoelectric, and electrical behavior of the doped LNN ceramics correlates with these structural changes.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"CONCLUSIONS","content":"\u003cp\u003eThe current work thoroughly investigated the effect of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e doping of the structural, optical, vibrational, and thermal properties of Li\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e (LNN) ceramics obtained by the process through the conventional solid-state methods. The most important findings are enumerated as follows:\u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eThe x-ray diffraction showed that the structure of all samples was single-phase orthorhombic perovskite. Partial with the low level V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e doping (x\u0026thinsp;=\u0026thinsp;1 mol%) The simultaneous presence of the orthorhombic and tetragonal phases, but the larger levels of doping (x\u0026thinsp;\u0026ge;\u0026thinsp;3 mol%) led to lattice distortions, so that the orthorhombic symmetry tended to regain its stability. The efficient occupancy of the smaller ions of V\u003csup\u003e5+\u003c/sup\u003e at the positions of Nb\u003csup\u003e5+\u003c/sup\u003e, leading to the lattice contraction and high localized strain, is represented by the variation in relative intensities and peak shifts to high 2θ values.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eThe SEM experiment revealed that the best V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e concentration produced good grain formation and densification and this ought to translate to increased dielectric and piezoelectric properties. There was a slight reduction in the grain uniformity due to excessive addition of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e proving that the optimum doping regime to achieve microstructural refinement was accomplished.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eBoth Raman spectroscopy and FTIR revealed a variation in the local lattice dynamics as well as vibrational modes of the Nb-O bond, which demonstrates that the addition of vanadium alters the bonding environment and lattice symmetry.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eThe depiction of changes in the electronic structure due to the introduction of defect states by the dopants was reflected in the UV-Vis spectrum with the band optical gap increasing steadily with V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e concentration.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eDifferential scanning calorimetry revealed changes in the phase transition temperatures on the addition of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e, implying that doping of LNN ceramics can change their thermal stability and lattice dynamics. Lower levels of doping reduced the Curie temperature slightly, whereas higher levels raised the transition, which implies more disorder and lattice stress.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eThese results imply that V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e can be employed as an effective dopant to tailor structural, microstructural, optical, vibrational and thermal properties of LNN ceramics. Regulated doping can offer a solution to optimizing piezoelectric ceramics based on LNN-based piezoelectric using lead-free materials by modulating lattice dynamics, improving densification, and creating a partial tetragonal phase to meet the current electronic and dielectric every day demands.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eKamala: Conceptualization, Methodology, Software, Data curation, Writing- Original draft preparation. Ramalingeswara Rao: Visualization, Investigation. Software, Validation.: Ramesh: Writing- Reviewing and Editing, Supervision.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eDevi DK, Manisha M, Venkatesham N, Edukondalu A, Raghupathi P, Prasad. BV (2026) J Mol Struct 1349(1):143603. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.molstruc.2025.143603\u003c/span\u003e\u003cspan address=\"10.1016/j.molstruc.2025.143603\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang W, Yuan X, Ma C, Tang F, Wang F, Cao Y (2015) Ceram Int 41:8377\u0026ndash;8381. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ceramint.2015.03.028\u003c/span\u003e\u003cspan address=\"10.1016/j.ceramint.2015.03.028\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang W, Li P, Li F, Liu X, Shen B, Zhai J (2018) Ceram Int 45:2275\u0026ndash;2280. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ceramint.2018.10.141\u003c/span\u003e\u003cspan address=\"10.1016/j.ceramint.2018.10.141\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFu Z, Yang J, Lu P, Zhang L, Yao H, Xu F, Li Y (2017) Ceram Int 43:12893\u0026ndash;12897. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ceramint.2017.06.185\u003c/span\u003e\u003cspan address=\"10.1016/j.ceramint.2017.06.185\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXu F, Chen J, Lu Y, Zhang Q, Zhang Q, Zhou T, He Y (2018) Ceram Int 44:16745. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ceramint.2018.06.104\u003c/span\u003e\u003cspan address=\"10.1016/j.ceramint.2018.06.104\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhen Y, Li J-F, Wang K, Yan Y, Yu L (2011) Mater Sci Eng B 176:1110\u0026ndash;1114. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.mseb.2011.05.051\u003c/span\u003e\u003cspan address=\"10.1016/j.mseb.2011.05.051\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJu\u0026aacute;rez RL, Garc\u0026iacute;a FG, Gonz\u0026aacute;lez RE (2011) J Alloy Comp 509:3837. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jallcom.2010.12.103\u003c/span\u003e\u003cspan address=\"10.1016/j.jallcom.2010.12.103\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMaiwa H (2016) Ferroelectrics 491:71\u0026ndash;78. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1080/00150193.2015.1071610\u003c/span\u003e\u003cspan address=\"10.1080/00150193.2015.1071610\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIchiki M, Zhang L, Maeda R, Eur J (2004) Ceram Soc 24:1693\u0026ndash;1697. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0955-2219(03)00475-8\u003c/span\u003e\u003cspan address=\"10.1016/S0955-2219(03)00475-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi K, Li FL, Wang Y, Chan HLW (2011) Mater Chem Phys 131:320. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.matchemphys.2011.09.048\u003c/span\u003e\u003cspan address=\"10.1016/j.matchemphys.2011.09.048\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang Y, Damjanovic D, Klein N, Setter N (2008) J. Am. Ceram. Soc. 91 1962. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/j.1551-2916.2008.02392.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1551-2916.2008.02392.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIzzuddin I, Jumali MHH, Zainuddin Z (2014) AIP Conf. Proc. 90\u0026ndash;93. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1063/1.4895177\u003c/span\u003e\u003cspan address=\"10.1063/1.4895177\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang Y, Wang S, Zhang N, Wang A, Zhu Y, Cai F (2018) Ceram Int 8380. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ceramint.2018.02.030\u003c/span\u003e\u003cspan address=\"10.1016/j.ceramint.2018.02.030\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGaur R, Dhingra A, Pal S, Singh KC (2015) J Alloy Comp 625:284\u0026ndash;290. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jallcom.2014.11.134\u003c/span\u003e\u003cspan address=\"10.1016/j.jallcom.2014.11.134\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang H, Zuo R, Fu J, Liu Y (2011) J Alloy Comp 509:936\u0026ndash;941. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jallcom.2010.09.134\u003c/span\u003e\u003cspan address=\"10.1016/j.jallcom.2010.09.134\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen C, Huang Y, Tan Y, Sheng Y (2016) J Alloy Comp 663:46\u0026ndash;51. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jallcom.2015.12.106\u003c/span\u003e\u003cspan address=\"10.1016/j.jallcom.2015.12.106\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSaeri MR, Barzegar A, Ahmadi Moghadam H (2011) Ceram Int 37:3083\u0026ndash;3087. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ceramint.2011.05.044\u003c/span\u003e\u003cspan address=\"10.1016/j.ceramint.2011.05.044\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIzzuddin I, Zainuddina Z, Janil NH (2019) Ceram Int 45:17204. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ceramint.2019.05.275\u003c/span\u003e\u003cspan address=\"10.1016/j.ceramint.2019.05.275\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTzou WC, Chen YC, Cheng PS (2000) J Eur Ceram Soc 20:991. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0955-2219(99)00228-9\u003c/span\u003e\u003cspan address=\"10.1016/S0955-2219(99)00228-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHuang CL, Chen YC (2003) J Eur Ceram Soc 23:167\u0026ndash;173. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0955-2219(02)00086-9\u003c/span\u003e\u003cspan address=\"10.1016/S0955-2219(02)00086-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJean JH, Lee CH (2001) Jpn J Appl Phys 40:2232\u0026ndash;2236. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1142/S0217984914500651\u003c/span\u003e\u003cspan address=\"10.1142/S0217984914500651\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhai X, Wang H, Xu J, Yuan C, Zhang X, Zhou C, Liu X (2013) J Mater Sci: Mater Electron 24:687\u0026ndash;691. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10854-012-0794-6\u003c/span\u003e\u003cspan address=\"10.1007/s10854-012-0794-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAmrita Nayak PK, Das SK, Patri (2020) AIP Conf. Proc. 2265 030205. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1063/5.0017556\u003c/span\u003e\u003cspan address=\"10.1063/5.0017556\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWu JG, Xiao DQ, Zhu JG, Yu PJ (2008) Appl Phys Lett 103:024102. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1063/1.2830997\u003c/span\u003e\u003cspan address=\"10.1063/1.2830997\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHao JG, Chu RQ, Zang GZ, Li GR (2009) J Alloys Compd 479:376\u0026ndash;380. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jallcom.2008.12.069\u003c/span\u003e\u003cspan address=\"10.1016/j.jallcom.2008.12.069\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAhart M, Somayazulu M, Cohen RE, Ganesh P, Dera P, Mao HK, Hemley RJ, Ren Y, Liermann P, Wu ZG (2008) Nature 451:545\u0026ndash;552. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/nature06459\u003c/span\u003e\u003cspan address=\"10.1038/nature06459\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXiao Y, Cheng D, Li G, Yin R, Li P, Gao Z (2025) J Electroceram. (in Press) \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10832-025-00391-3\u003c/span\u003e\u003cspan address=\"10.1007/s10832-025-00391-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKambale KR, Shroff S, Butee SP, Singh R, Kulkarni AR (2017) Ferroelectrics 518(1). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1080/00150193.2017.1360600\u003c/span\u003e\u003cspan address=\"10.1080/00150193.2017.1360600\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. )94\u0026thinsp;\u0026ndash;\u0026thinsp;10\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNavaneetha P, Kalyani B, Edukondalu A, Kumar NH, Vardhani CP (2024) M S Reddy Chem Pap 78:5851\u0026ndash;5864. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s11696-024-03489-0\u003c/span\u003e\u003cspan address=\"10.1007/s11696-024-03489-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang K, Li J (2012) J Adv Ceram 1:24\u0026ndash;37. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s40145-012-0003-3\u003c/span\u003e\u003cspan address=\"10.1007/s40145-012-0003-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDavis EA, Mott NF (1970) Philos Mag 22:903. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1080/14786437008221061\u003c/span\u003e\u003cspan address=\"10.1080/14786437008221061\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTauc J, Menth A, Non-Cryst J (1972) Solids 8:569. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/0022-3093(72)90194-9\u003c/span\u003e\u003cspan address=\"10.1016/0022-3093(72)90194-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChai QZ, Zhao XM, Chao XL, Yang ZP (2017) RSC Adv 7:28428. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.scriptamat.2018.05.022\u003c/span\u003e\u003cspan address=\"10.1016/j.scriptamat.2018.05.022\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi Z, Gao L, Zhang C, Li F, Energy J, Storage 119 116336, Gio P, Bau T, Hoai N, Nam N (2025) J. Mater. Sci. Chem. Eng. 8 (2020) 1\u0026ndash;11. 10.4236/msce.2020.87001\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHou J, Dai Z, Liu C, Yasui S, Cong Y (2023) Sh Gu J Alloys Compd 960:170639. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jallcom.2023.170639\u003c/span\u003e\u003cspan address=\"10.1016/j.jallcom.2023.170639\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eUrbach F (1953) Phys Rev 92:1324. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1103/PhysRev.92.1324\u003c/span\u003e\u003cspan address=\"10.1103/PhysRev.92.1324\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEdukondalu A, Rahman S, Siva Kumar K, Sreenivasu D (2014) Vib Spectrosc 71:91\u0026ndash;97. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.vibspec.2014.01.010\u003c/span\u003e\u003cspan address=\"10.1016/j.vibspec.2014.01.010\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEdukondalu A, Sathe V, Rahman S, Siva Kumar K (2014) Phys B 438:120\u0026ndash;126. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.physb.2014.01.014\u003c/span\u003e\u003cspan address=\"10.1016/j.physb.2014.01.014\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSilverstein RM, Webster FX (2005) Spectrometric Identification of Organic Compounds, 7th edn. Wiley\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDai Y, Zhang X, Zhou G (2007) Appl Phys Lett 90(26):262903. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1063/1.2751607\u003c/span\u003e\u003cspan address=\"10.1063/1.2751607\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang H, Luo H, Liang M, Ma H, Lv D, Qu F, Yin Y, Zhou Y, Zhang X, Zhao H, Miao Z (2025) Rare Met 44:4642\u0026ndash;4656. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s12598-025-03325-8\u003c/span\u003e\u003cspan address=\"10.1007/s12598-025-03325-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChongtham Jiten K, Chandramani Singh (2017) J Mater Sci: Mater Electron 28:507\u0026ndash;513. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10854-016-5551-9\u003c/span\u003e\u003cspan address=\"10.1007/s10854-016-5551-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLubszczyk M, Brylewski T, Konieczny K, Kruk A (2024) J Alloys Compd 996:174814. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jallcom.2024.174814\u003c/span\u003e\u003cspan address=\"10.1016/j.jallcom.2024.174814\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMarta Val\u0026aacute;škov\u0026aacute; K, Chrob\u0026aacute;ček B, Novosad S, Martynkov\u0026aacute; (2018) Mater. Today Proc. 5(1) S96-S102. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.matpr.2018.05.062\u003c/span\u003e\u003cspan address=\"10.1016/j.matpr.2018.05.062\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuo Y, Kakimoto K, Ohsato H (2004) Appl Phys Lett 85:4121. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1063/1.1813636\u003c/span\u003e\u003cspan address=\"10.1063/1.1813636\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSaito Y, Takao H, Tani T, Nonoyama T, Takatori K, Homma T, Nagaya T, Nakamura M (2004) Nature 432:84. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/nature03028\u003c/span\u003e\u003cspan address=\"10.1038/nature03028\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJuang YD (2001) Solid State Commun 120:25. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0038-1098(01)00322-2\u003c/span\u003e\u003cspan address=\"10.1016/S0038-1098(01)00322-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDai SB, Juang YD, Hwang JS, Chu SY (2003) J Cryst Growth 257:316. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0022-0248(03)01475-1\u003c/span\u003e\u003cspan address=\"10.1016/S0022-0248(03)01475-1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKirana K, Gangadhar V, Prasad G (2019) Mater. Today Proc. 11 (3) 971\u0026ndash;979 \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.matpr.2018.12.026\u003c/span\u003e\u003cspan address=\"10.1016/j.matpr.2018.12.026\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCheng X (2014) Ceram Int 40(4):5771\u0026ndash;5779. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ceramint.2013.11.016\u003c/span\u003e\u003cspan address=\"10.1016/j.ceramint.2013.11.016\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKakimoto K (2005) Japanese J. Appl. Phys. 44(9S) 7064. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1143/JJAP.44.7064\u003c/span\u003e\u003cspan address=\"10.1143/JJAP.44.7064\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTrodahl HJ (2008) Appl Phys Lett 4 93(26):262901. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1063/1.3056658\u003c/span\u003e\u003cspan address=\"10.1063/1.3056658\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKalyani B, Pujari N, Edukondalu A, Reddy MS, Vardhani CP (2022) Mater Lett 317:132128\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCosta MM, Pires GFM, Terezo AJ, Grac MPF, Sombra ASB (2011) J Appl Phys 110:1\u0026ndash;7\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eParida BN, Padhee R, Choudhary RNP (2012) J Phys Chem Solid 73:713\u0026ndash;719\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuo Y, Kakimoto K, Ohsato H (2004) Appl Phys Lett 85:4121\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBadapanda T, Harichandan R, Kumar TB, Mishra SR, Anwar S (2016) J Mater Sci Mater Electron 27:7211\u0026ndash;7221\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFarea AMM, Kumar S, Batoo KM, Yousef A (2008) Alimuddin Phys B Condens Matter 403:684\u0026ndash;701\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSahoo S, Das S, Mahapatra PK, Choudhary RNP (2018) Mater Chem Phys 216:158\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDhak P, Dhak D, Das M, Pramanik K, Pramanik P (2009) Mater Sci Eng B 164:165\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"chemical-papers","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"chpa","sideBox":"Learn more about [Chemical Papers](http://link.springer.com/journal/11696)","snPcode":"11696","submissionUrl":"https://www.editorialmanager.com/CHPA/default.aspx","title":"Chemical Papers","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Lead-free ceramics, Perovskite structure, Optical band gap, X-ray diffraction (XRD), Microstructure","lastPublishedDoi":"10.21203/rs.3.rs-8881891/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8881891/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study explores the thermal, optical, vibrational and structural properties of lead-free Li\u003csub\u003e0.5\u003c/sub\u003eNa\u003csub\u003e0.5\u003c/sub\u003eNbO\u003csub\u003e3\u003c/sub\u003e (LNN) ceramics to a different concentration of V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e (0, 1, 3, 5, and 9 mol). The samples were prepared in the older solid-state method of reaction. The formation of a single phase orthorhombic perovskite structure was confirmed by X-ray diffraction (XRD) yet there was slight displacement of the XRD patterns implying that there were minimal secondary phases. The peaks of diffraction were evidence of the effective inclusion of the vanadium in the lattice. DSC analysis displayed that V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e addition changed the optical investigations with the aid of UV-Vis spectroscopy displayed progressive changes in the optical band gap, which are indicative of a dopant alteration in the electronic structure created by defect states. Scanning electron microscopy (SEM) showed improvement in grain growth and densification. FTIR and Raman spectroscopy of Nb-O bond vibrations and local structural order showed that these results were found at optimal doping concentrations, further supporting these findings. The V\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e was found to enhance the microstructural and functional properties of LNN ceramics, and they will be suitable in future lead-free electronic and dielectric devices.\u003c/p\u003e","manuscriptTitle":"Structural, Optical, and Vibrational Behavior of V₂O₅-Doped Li₀.₅Na₀.₅NbO₃ Ceramics","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-23 05:56:41","doi":"10.21203/rs.3.rs-8881891/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-02-20T14:31:08+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-18T07:26:13+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"212784056290941770546228913008955250330","date":"2026-02-18T05:16:58+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-17T16:40:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"74974941572200185080732658132451347675","date":"2026-02-17T12:49:29+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-17T12:34:56+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-17T12:33:45+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-16T15:54:36+00:00","index":"","fulltext":""},{"type":"submitted","content":"Chemical Papers","date":"2026-02-14T17:52:26+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"chemical-papers","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"chpa","sideBox":"Learn more about [Chemical Papers](http://link.springer.com/journal/11696)","snPcode":"11696","submissionUrl":"https://www.editorialmanager.com/CHPA/default.aspx","title":"Chemical Papers","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"718ed70a-ff0b-4d69-98a4-46724dfea46b","owner":[],"postedDate":"February 23rd, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-04-07T16:04:17+00:00","versionOfRecord":{"articleIdentity":"rs-8881891","link":"https://doi.org/10.1007/s11696-026-04802-9","journal":{"identity":"chemical-papers","isVorOnly":false,"title":"Chemical Papers"},"publishedOn":"2026-04-03 15:58:23","publishedOnDateReadable":"April 3rd, 2026"},"versionCreatedAt":"2026-02-23 05:56:41","video":"","vorDoi":"10.1007/s11696-026-04802-9","vorDoiUrl":"https://doi.org/10.1007/s11696-026-04802-9","workflowStages":[]},"version":"v1","identity":"rs-8881891","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8881891","identity":"rs-8881891","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}