Achieving Ferromagnetism in Single-Crystalline Bismuth Ferrite Nanoparticles through Jet Milling

Achieving Ferromagnetism in Single-Crystalline Bismuth Ferrite Nanoparticles through Jet Milling | 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 Achieving Ferromagnetism in Single-Crystalline Bismuth Ferrite Nanoparticles through Jet Milling Aarthy Thirugnanam, Abhishek Shukla, Adhila TK, Rajasekar Parasuraman, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6470902/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 18 Aug, 2025 Read the published version in Journal of Nanoparticle Research → Version 1 posted 9 You are reading this latest preprint version Abstract Bismuth ferrite, a multiferroic material known for its associated ferroelectric and antiferromagnetic properties, holds significant potential for advanced applications in memory devices, sensors, and electrocatalysts. However, achieving a simultaneous increase in both magnetization and coercivity while preserving the material’s single-crystallinity has been a considerable challenge, especially in phase-pure bismuth ferrite. In this work, we synthesized phase-pure BiFeO 3 nanoparticles using the sol-gel method and subjected them to jet milling at varying pressures. Detailed electron microscopy studies demonstrate that the jet milling process maintains the single-crystalline nature of BiFeO 3 while significantly reducing the particle size. The jet-milled samples exhibited up to a 10 increase in magnetization (~ 10 emu/g) and a 30 times improvement in coercivity (> 1000 Oe) compared to the as-synthesized samples. This enhancement is attributed to the disruption of the cycloidal spin structure due to the reduced crystallite size and reduced agglomeration of the particles. This work presents jet milling as an effective technique for enhancing the magnetic performance of BiFeO 3 , with potential applications in multiferroic devices and other advanced technologies. Bismuth ferrite Jet milling Nanoparticles Single-crystalline Size effect Ferromagnetism Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Introduction Multiferroics materials, which possess concurrent ferroelectric and antiferromagnetic orders, are a promising class of materials due to their potential applications in low-power consumption memory devices, sensing, actuation, and tunnel junction, etc [ 1 – 3 ]. Among the multiferroic material, the bismuth ferrite BiFeO 3 (BFO) is state of art material that is both magnetic and strongly ferroelectric at room temperature [ 1 – 3 ], This suggests that an electric field can change a material's magnetization, and a magnetic field can change a material's polarization. Due to the property's extreme rarity in the natural world, there has been a lot of interest in BiFeO 3 . The main effort in BiFeO 3 studies has been devoted to understanding the antiferromagnetic to ferromagnetic transition at room temperature [ 4 ]. BiFeO 3 has Type 1 multiferroics with distorted rhombohedral perovskite structure. In bulk has ferroelectricity below Curie temperature (T C ≈ 830°C) and G-type antiferromagnetic ordering below Neel temperature (T N ≈ 370°C). It is known that ferroelectricity properties are due to Fe 3+ and Bi 3+ ions, which are displaced from their centrosymmetric positions resulting in spontaneous polarization along the direction [111] [ 5 – 6 ]. The Dzyaloshinskii-Moriya interaction (DMI) is a major factor in the antiferromagnetism of bismuth ferrite because of spin-orbit coupling and the lack of inversion symmetry in the crystal structure. The DMI introduces a term to the spin Hamiltonian that favors a canted alignment of neighboring spins, in contrast to the strictly antiparallel configuration typical of conventional antiferromagnetism. The DMI, arising from spin-orbit coupling in systems lacking inversion symmetry, promotes a non-collinear spin arrangement [ 7 – 8 ]. In BiFeO 3 , this interaction stabilizes a long-wavelength cycloidal spin structure, where the spins rotate in a plane as they propagate through the material. The spin cycloid in BiFeO 3 exhibits a periodicity of about 62 nm, significantly influenced by the strength of the DMI. To modify the antiferromagnetic material such as BiFeO 3 to achieve ferromagnetism, the cycloid has to be broken and that can be typically achieved by strain, chemical doping, and formation of nanostructured materials [ 9 – 13 ]. The BFO ferromagnetic response has been studied using different methods, such as applying a high field, reducing the particle size, and doping. Doping in BFO samples is done in different ways (a) Chemical substitution of Bi 3+ ions in A sites by dopant ions like La 3+ , Sr 2+ , Er 3+ , Ba 2+ [ 14 – 17 ] (b) the B sites of Fe 3+ are chemically substituted by Ti 4+ , Nb 5+ o Ni 2+ [ 18 – 19 ] (c) or co-doped by A and B positions with Zn 2+ and Ni 2+ [ 20 ]. Despite the application of several mentioned techniques, achieving a pure phase of BiFeO 3 nanoparticles with a single crystalline nature while maintaining ferromagnetic properties remains challenging. The single crystallinity of BiFeO 3 nanoparticles is crucial, and while this has been achieved in nanostructure preparations, scaling up the formation of such structures is difficult. Size reduction methods, such as ball milling, have been employed to induce ferromagnetic properties; however, this often results in polycrystallinity and the introduction of impurities [ 21 – 22 ]. Jet milling offers a viable alternative, which is using a high-velocity air or gas jet to pulverize particles to nanoscale dimensions, relying on particle-particle interactions to achieve size reduction. This technique is particularly effective for brittle materials like BiFeO 3 and significantly reduces contamination risks compared to ball milling, as the particle fracture process minimizes interactions with the milling medium and vial. Additionally, jet milling helps preserve the single crystallinity of the material [ 23 – 25 ]. In this study, we synthesized antiferromagnetic single-crystalline BiFeO 3 nanoparticles using the sol-gel method. These nanoparticles were subsequently subjected to jet milling to reduce both agglomeration and particle size. Transmission Electron Microscopy (TEM) analyses were conducted to examine the crystallinity of the as-produced and jet-milled particles. The magnetic properties of these particles were also investigated, revealing some of the highest ferromagnetic properties directly obtained from the pure phase. Experimental Section The process consisted of dissolving the bismuth nitrate [Bi(NO 3 ).5H 2 O (SDFCL)] and iron nitrate [Fe(NO 3 ) 3 .9H 2 O (High purity laboratory chemicals pvt. Ltd)], in ethylene glycol (SRLchem) in required mole percentages. The solution was dissolved in a glass beaker over a magnetic stirring hot plate at 65°C covered with a watch glass to avoid evaporation and stirred continuously. Once all reactants were dissolved, the glass beaker was uncovered to allow evaporation and gel drying. The gel had a brown-yellow colour. The gel was washed three times with double distilled water, and acetone and collected by centrifuging at 10,000 rpm. Washing is done to remove the solvent (unreacted ethylene glycol removal). The samples were then oven-dried at 70°C, which allowed the powder to dry. Ground to a fine powder and transferred into a silica crucible, the samples were calcined at 600°C. After one hour, the furnace was turned off and allowed to cool naturally [ 26 ]. These powders were then subjected to jet milling using compressed air in ambiance. About 5 grams of the BiFeO 3 powders were taken each time for milling at different pressures (2 bar, 4 bar, and 6 bar). The X-ray diffraction (XRD) pattern of the prepared sample was analysed using a Bruker D8 Advanced powdered diffractometer. ​The samples were distributed over carbon tape and subsequently gold coated and the scanning electron microscope imaging was performed using the Thermo Scientific APREO 2 FESEM. BiFeO 3 nanoparticles were dispersed in ethanol and then subjected to ultrasonication for 10 to 20 minutes to ensure a uniform dispersion. Following this, a 1 µL droplet of the dispersion was cast onto a carbon-coated copper TEM grid. A plasma cleaning procedure was applied to the sample for one minute, after which the TEM grid, containing the sample, was positioned within a JEOL JEM F200 electron microscope equipped with a GIF Continuum K3 system. ​Imaging and EELS analysis were conducted at an operational voltage of 200 kV.​ The EELS spectra were recorded with a full-width half maxima (FWHM) of ~ 1.5 eV and a dispersion of 0.30 eV/channel. The convergence semi-angle and the collection semi-angle were measured to be 36.24 mrad and 29.60 mrad, respectively. The magnetic hysteresis was traced using a built-in vibrating sample magnetometer of the physical property measurement system (PPMS), procured from Dyna-Cool, USA with the applied magnetic field of ± 2 T. Results and Discussions The X-ray diffraction pattern of the as-synthesized BiFeO 3 nanoparticles is shown in Fig. 1. The diffraction peaks observed correspond to the rhombohedral perovskite structure of BiFeO 3 with R3c space group [ 27 ]. The sharpness of the peak suggests that the crystallinity in the sol-gel synthesized BiFeO 3 nanoparticles. The samples were then subjected to jet milling at different pressures. The X-ray diffraction patterns of BiFeO 3 nanoparticles subjected to jet milling at different pressures (4 bar and 6 bar) are shown in Fig. 1. Both XRD patterns display characteristic peaks corresponding to the rhombohedral perovskite structure of BiFeO 3 , consistent with the sol-gel synthesized samples. The SEM images and analyses for the as-synthesized BiFeO 3 nanoparticles and the particles that are jet-milled at 4 bar pressure are shown in Fig. 2 . The as-prepared sample exhibits a collection of nanoparticles with irregular shapes and a significant degree of agglomeration, with many of them clustered together due to the inherent nature of the sol-gel synthesis process that involves calcination (Fig. 2 A-C). The particle size distribution is relatively broad, with particle lengths ranging from approximately 40 nm to 160 nm. The distribution shows a peak around 70–80 nm, indicating that the majority of the particles fall within this size range (Fig. 2 D). After subjecting the BiFeO 3 nanoparticles to jet milling at a pressure of 4 bar (Fig. 2 E-G), significant changes in the particle morphology are observed. The jet milling process effectively reduced the size of the agglomerates (Fig. 2 E-F). Further, we can observe that the particles are separated and in addition, these individual particles are covered with a debris of fine particles (Fig. 2 G). The particle size distribution of the jet-milled BiFeO 3 nanoparticles is presented in the histogram shown in Fig. 2 H. The jet-milled particles exhibit a size distribution mostly between 30 nm and 120 nm with the peak of distribution around 30 and 50 nm. The particle size has clearly shifted towards a smaller size in comparison to the as-synthesized samples. Note that after jet milling, the majority of the particles are less than 62 nm, the length of the spin cycloid [ 9 ]. The samples were then subjected to TEM studies to understand the crystal structure, crystallinity of the particles, and, the oxidation state of the ions in the samples. Figure 3 A shows the bright-field TEM image of the as-synthesized BiFeO 3 particles. The diffraction pattern was indexed and it shows that the particles are crystalline and they belong to the bismuth ferrite rhombohedral phase (Fig. 3 B). However, the diffraction pattern was not continuous and smooth indicating that the particles were larger in size. To investigate the crystallinity of the samples, high-resolution TEM imaging was performed (Fig. 3 C). The FFT taken from the entire region in Fig. 3 C is given in the inset of the image. We can see the single-crystal pattern that has been indexed to the zone axis [-2 -1 -1]. The planes corresponded to the rhombohedral structure of bismuth ferrite. The zoomed-in region from Fig. 3 C is given in Fig. 3 D along with the indexing of the planes. Such high-resolution imaging has been performed on several other particles in the as-synthesized bismuth ferrite powder (Figure S1 ) and the sample was found to be single-crystalline with larger crystallite size. Further, the samples jet-milled at 4 bar pressure are subjected to TEM studies (Fig. 4 ). We can observe that the size of the particles in Fig. 4 A is smaller in size compared to Fig. 3 A. Further, the diffraction rings are complete and well-defined in the jet-milled samples indicating that the crystallite size has reduced in the jet-milled samples (Fig. 4 B). It can be observed from the HRTEM and the corresponding FFT shown in the inset of Fig. 4 C, single-crystalline nature of the samples is preserved in the jet-milled samples. Figure 4 D corresponds to the inverse FFT of a region from Fig. 4 C, highlighting the crystalline ordering of atomic planes in the milled samples. The single-crystalline nature of the milled particles were further confirmed through imaging multiple particles (Figure S2). This is one of the important benefits of utilizing jet milling technique in contrast to other pulverisation techniques, because of the fact that here the particle-particle interaction is happening. Furthermore, the brittle nature of bismuth ferrite facilitates the effective fragmentation of particles into smaller, uniform sizes during the milling process. To investigate the effect of jet milling on the magnetic properties of BiFeO 3 nanoparticles, the samples were analyzed using a PPMS setup. Figure 5 shows the magnetic properties for the as-synthesized and the particles that were jet milled at different pressures. Figure 5 A shows the hysteresis loop for the as-synthesized BiFeO 3 sample, which exhibits very low magnetization and coercivity, typical of its antiferromagnetic nature. The low magnetic response confirms the purity and antiferromagnetic order of the as-synthesized BiFeO 3 nanoparticles [ 28 ]. Figure 5 B shows the magnetic behavior of BiFeO 3 samples subjected to jet milling at pressures of 2 bar, 4 bar, and 6 bar. The jet milling process significantly enhances the magnetic properties, particularly at higher milling pressures. The samples milled at 4 bar and 6 bar show a remarkable increase in saturation magnetization and coercivity, indicating a transition towards ferromagnetic behavior. The observed enhancement in magnetization is attributed to the disruption of the cycloidal spin structure due to the reduction in particle size achieved through jet milling (Fig. 2 ). The maximum magnetization obtained for the as-synthesized samples correspond to M s ~ 0.91 emu/g. The jet-milled samples exhibited a M s ~ 10 emu/g. Showing that the magnetization value has easily been increased about 10 times. This can be directly attributed to the reduced particle size in jet-milled samples where magnetization improves due to the contribution from uncompensated spins at the surface of the nanoparticles. By noting the coercivity ( H c ) values, we obtained about 30 percent improvement. However, by noting the nature of the hysteresis loop, we can observe that the plot has a dip near zero magnetic field, indicating the possibility of contribution from the decomposed phase (Fig. 1). In order to understand the effect of particle size, we have taken the jet-milled samples and subjected to annealing at 400°C in ambient atmosphere for one hour of time. The samples were then furnace cooled. The magnetic hysteresis plots are shown in Fig. 6 . The magnetic parameters for the as-synthesized, jet-milled and annealed samples after jet-milled bismuth ferrite powders are summarized in Table – I. It can be seen that the magnetization of the samples has come down to that nearly of the as-synthesized samples. However, the coercivity value is about 20 times higher in the jet-milled-annealed samples in comparison to the as-synthesized samples. SEM micrograph for one of the annealed samples (jet-milled at 4 bar and annealed at 400°C for 1 h) is shown in Fig. 7 . It can be seen that the debris of smaller particles have become insignificant. However, the agglomeration of the particles is still not present (compare with Fig. 2 ). The aggregation of nanoparticles significantly influences their magnetic properties. Strong aggregation can result in a more homogeneous magnetic environment, which reduces the distinct contributions of individual particles to coercivity [ 29 ]. When the spacing between magnetic nanoparticles increases, the strength of interparticle interactions weakens, allowing the magnetic moments of individual particles to remain more independent. This independence is essential for preserving the anisotropic properties of each particle, which are critical for achieving and maintaining high coercivity [ 30 – 37 ]. Table I: Magnetic parameters for as-synthesized; jet-milled; annealed BiFeO 3 nanoparticles Sample M s @ 20 kOe (emu/g) M r (emu/g) M r / M s H c (Oe) M s ratio (as-synthesized) Vs. others H c ratio (as-synthesized) Vs. others As-synthesized 0.9 0.06 0.06 40 1 1 Jet-milled@2 bar 0.4 0.03 0.08 95 0.5 2.4 Jet-milled@4 bar 12.5 4.2 0.3 1450 13.7 36.2 Jet-milled@6 bar 9.9 3.3 0.3 1330 10.9 33.2 Jet-milled@4 bar, Annealed 1.8 0.4 0.2 720 2.1 18 Jet-milled@6 bar, Annealed 1.2 0.3 0.3 1200 1.4 30 Conclusions In this study, we have synthesized single-crystalline BiFeO 3 nanoparticles using the sol-gel method and subsequently enhanced their magnetic properties through jet milling. The primary focus was on understanding the impact of jet milling on the structural and magnetic characteristics of BiFeO 3 . The jet milling process effectively reduced the particle size and minimized agglomeration without compromising the single-crystalline nature of the BiFeO 3 nanoparticles. A significant increase in both saturation magnetization and coercivity was observed in the jet-milled samples. The disruption of the cycloidal spin structure, along with the reduction in particle size and reduced agglomeration, have contributed to the observed transition from antiferromagnetic to ferromagnetic behavior. So far, achieving simultaneous increases in both magnetization and coercivity has been largely limited to composite materials [ 38 ]. However, this is difficult to achieve in phase-pure bismuth ferrite samples. Our study demonstrates a significant enhancement in these properties in phase-pure BiFeO 3 , as shown in Fig. 8 , where our results are compared with those from other studies. Due to their phase-pure single crystallinity and enhanced ferromagnetic properties, these BiFeO 3 nanoparticles have significant potential for applications in soft magnetics, magnetic electrocatalysts, photocatalysts, memory devices, and more. The minimal agglomeration of these particles also increases the availability of active sites, making them particularly effective for electrocatalytic applications. It is noteworthy that, unlike conventional pulverized milling, the jet milling process is significantly faster, requiring only about 60 seconds to mill 5 grams of BiFeO 3 . This makes jet milling a highly efficient method for enhancing the magnetization of materials. The results of this study suggest that jet milling could be a valuable technique for other ferroelectric, piezoelectric, and ferromagnetic materials, particularly those that are brittle in nature. This approach holds promise for the development of advanced materials with superior magnetic performance while preserving their crystalline structure. Declarations Conflict of interest The authors declare no competing interests. Funding EH and MS express their gratitude to the Science and Engineering Research Board - Start-up Research Grant (SRG/2023/001939) program for funding the research, and ATK thanks the Science and Engineering Research Board - National Post Doctoral Fellowship (PDF/2023/003946) fellowship for supporting this research work. Author Contribution Author contribution EH organized the overall research and , AT did the prepared the BFO samples, and measured the properties and AS analyzed the TEM data, and ATK has written most of the manuscript. RS discussed the direction and schedule of the research with EH. PDB and RG designed the protocol of jet milling of as synthesized BFO samples. Acknowledgement The authors gratefully acknowledge the support provided by Office of Industrial Consultancy and Sponsored Research (IC&SR) and National Facility for Atom Probe Tomography (NFAPT) at Indian Institute of Technology Madras for facilitating our XRD, SEM, and TEM experiments. 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Supplementary Files SupportingInformation.docx Cite Share Download PDF Status: Published Journal Publication published 18 Aug, 2025 Read the published version in Journal of Nanoparticle Research → Version 1 posted Editorial decision: Revision requested 04 Jun, 2025 Reviews received at journal 26 May, 2025 Reviews received at journal 20 May, 2025 Reviewers agreed at journal 09 May, 2025 Reviewers agreed at journal 30 Apr, 2025 Reviewers invited by journal 30 Apr, 2025 Editor assigned by journal 20 Apr, 2025 Submission checks completed at journal 17 Apr, 2025 First submitted to journal 17 Apr, 2025 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. 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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-6470902","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":451694378,"identity":"51c95227-01e2-4df9-9b53-7486f9dbd355","order_by":0,"name":"Aarthy Thirugnanam","email":"","orcid":"","institution":"Vellore Institute of Technology","correspondingAuthor":false,"prefix":"","firstName":"Aarthy","middleName":"","lastName":"Thirugnanam","suffix":""},{"id":451694379,"identity":"c4c6d056-4b79-4b0e-a4f2-73dce05588a4","order_by":1,"name":"Abhishek Shukla","email":"","orcid":"","institution":"Indian Institute of Technology Madras","correspondingAuthor":false,"prefix":"","firstName":"Abhishek","middleName":"","lastName":"Shukla","suffix":""},{"id":451694380,"identity":"ba4c7ead-3d77-4ee0-acab-1e299854014b","order_by":2,"name":"Adhila TK","email":"","orcid":"","institution":"Indian Institute of Technology Madras","correspondingAuthor":false,"prefix":"","firstName":"Adhila","middleName":"","lastName":"TK","suffix":""},{"id":451694381,"identity":"9451f660-cbdd-4a7a-83f6-a6d55c09b8ef","order_by":3,"name":"Rajasekar Parasuraman","email":"","orcid":"","institution":"Vellore Institute of Technology","correspondingAuthor":false,"prefix":"","firstName":"Rajasekar","middleName":"","lastName":"Parasuraman","suffix":""},{"id":451694382,"identity":"74608982-f29b-49b0-9ac6-f22a06575bdf","order_by":4,"name":"Prabhu Delhi Babu","email":"","orcid":"","institution":"Centre for Automotive Energy Materials, International Advanced Research Centre for Powder Metallurgy and New Materials","correspondingAuthor":false,"prefix":"","firstName":"Prabhu","middleName":"Delhi","lastName":"Babu","suffix":""},{"id":451694383,"identity":"f238dbfa-840d-4bdf-aa63-717c2d0b9707","order_by":5,"name":"Raghavan Gopalan","email":"","orcid":"","institution":"Centre for Automotive Energy Materials, International Advanced Research Centre for Powder Metallurgy and New Materials","correspondingAuthor":false,"prefix":"","firstName":"Raghavan","middleName":"","lastName":"Gopalan","suffix":""},{"id":451694384,"identity":"df4725bd-c6c6-48b4-8475-1a4fa6f52343","order_by":6,"name":"Elangovan Hemaprabha","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6klEQVRIiWNgGAWjYDACCShtIMHA+ABI8/CRooXZAKSFjRQtbGA2QS380s1HN/zccU/eXLr5WeXXHDsZNgbmh49u4NEiOedY2s3eM8WGO+ccM7stuy0Z6DA2Y+McPFoMbuSY3eBtS2DccCPB7LbkNmagFh42aXxa7G/kf7v5ty3BfsON9G/FktvqCWsxkMhhuw20JXED0DrGj9sOE9YicSMN6IUzCck7Z+QUSzNuO87DxkzAL/wzkp/dfLsjwXa7RPrGjz+3Vdvzszc/fIxPCxgwNkBoZh4wSUg5shbGH8SoHgWjYBSMghEHABgWSrM9Qa+MAAAAAElFTkSuQmCC","orcid":"","institution":"Indian Institute of Technology Madras","correspondingAuthor":true,"prefix":"","firstName":"Elangovan","middleName":"","lastName":"Hemaprabha","suffix":""}],"badges":[],"createdAt":"2025-04-17 10:38:20","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6470902/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6470902/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s11051-025-06413-z","type":"published","date":"2025-08-18T16:28:57+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":81991040,"identity":"8d357145-52ac-4b83-b656-636f4af609e4","added_by":"auto","created_at":"2025-05-05 16:38:31","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":58258,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eXRD patterns for bismuth ferrite powders.\u003c/strong\u003e As-synthesized BiFeO\u003csub\u003e3\u003c/sub\u003e powder and the jet-milled samples show the diffraction peaks corresponding to the rhombohedral perovskite structure belonging to the space group R3c.\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6470902/v1/01fd4c648bd24dfcd6360b41.jpg"},{"id":81991320,"identity":"9fd1d506-d32b-4b32-a992-837737a716e6","added_by":"auto","created_at":"2025-05-05 16:46:31","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":165664,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSEM images of BiFeO\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e powders at different magnifications and the size distribution of the particles.\u003c/strong\u003e (\u003cstrong\u003eA-C\u003c/strong\u003e) As-synthesized sample showing larger, particles with significant agglomeration; (\u003cstrong\u003eD\u003c/strong\u003e) Particle size distribution of the as-synthesized sample indicating a peak around 70-80 nm. (\u003cstrong\u003eE-G\u003c/strong\u003e) Jet-milled sample at 4 bar pressure displaying reduced particle size and decrease in agglomeration; (\u003cstrong\u003eH\u003c/strong\u003e) Particle size distribution of the jet-milled sample showing a shift towards smaller, more particle sizes with a peak around 40-50 nm.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6470902/v1/04e0c5e5e90184aea0dcf2e1.jpg"},{"id":81991043,"identity":"c7fa8f5f-269d-49e8-a94a-79f4ac46a03d","added_by":"auto","created_at":"2025-05-05 16:38:32","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":128028,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSingle-crystalline bismuth ferrite powder from sol-gel synthesis.\u003c/strong\u003e (\u003cstrong\u003eA\u003c/strong\u003e) Bright-field TEM image of as-synthesized BiFeO\u003csub\u003e3\u003c/sub\u003e particles showing larger, crystalline particles. (\u003cstrong\u003eB\u003c/strong\u003e) Selected area electron diffraction (SAED) pattern indexed to the rhombohedral phase of bismuth ferrite, indicates the crystalline nature of the particles. (\u003cstrong\u003eC-D\u003c/strong\u003e) High-resolution TEM images showing the lattice fringes, with the inset in C, displaying the (FFT) pattern indexed to the zone axis [-2 -1 -1], confirming the single-crystalline nature of the sample.\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6470902/v1/b2788cd7b3b2d2fd7c16488a.jpg"},{"id":81991038,"identity":"68e7828a-d7d5-4537-966c-60c91c43854a","added_by":"auto","created_at":"2025-05-05 16:38:31","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":135340,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eTEM analysis of BiFeO\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e nanoparticles after jet milling at 4 bar pressure. \u003c/strong\u003e(\u003cstrong\u003eA\u003c/strong\u003e) Bright-field TEM image of as-synthesized BiFeO\u003csub\u003e3\u003c/sub\u003e particles and the corresponding diffraction is provided in Figure (\u003cstrong\u003eB\u003c/strong\u003e). The well-defined rings compared to the as-synthesized samples suggest the reduction in the crystallite size. (\u003cstrong\u003eC\u003c/strong\u003e) High-resolution TEM (HRTEM) image showing the lattice fringes, with the inset displaying the Fast Fourier Transform (FFT) pattern indexed to the zone axis [-2 -1 -1], confirming the single-crystalline nature of the sample. (\u003cstrong\u003eD\u003c/strong\u003e) Inverse FFT from C illustrating the clear lattice structure.\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6470902/v1/ec9ad00085bf3dc8ecc45280.jpg"},{"id":81991073,"identity":"51cd95c7-9351-4a77-b612-8bdbcd309189","added_by":"auto","created_at":"2025-05-05 16:38:33","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":41309,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eMagnetic hysteresis loops for as-synthesized and jet-milled BiFeO\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e powders.\u003c/strong\u003e (\u003cstrong\u003eA\u003c/strong\u003e) Magnetic hysteresis loop of as-synthesized BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles showing low magnetization and coercivity, consistent with their antiferromagnetic nature. (\u003cstrong\u003eB\u003c/strong\u003e) Hysteresis loops of BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles after jet milling at 2 bar, 4 bar, and 6 bar, illustrating the significant enhancement in magnetic properties, especially at higher milling pressures.\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6470902/v1/f310af607005f22434871ce5.jpg"},{"id":81991032,"identity":"57d32e2a-3ade-48b8-aa64-64abc8540722","added_by":"auto","created_at":"2025-05-05 16:38:31","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":33277,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eMagnetic hysteresis loops of BiFeO\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e nanoparticles that were jet-milled, followed by annealing. \u003c/strong\u003eThe magnetization of the annealed samples decreases to levels similar to those of the as-synthesized samples. However, the coercivity is significantly enhanced.\u003c/p\u003e","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6470902/v1/b10d2bc9a535ec2b8d485ad5.jpg"},{"id":81991070,"identity":"99acfc03-509d-4348-9cda-caf068f60dde","added_by":"auto","created_at":"2025-05-05 16:38:33","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":45205,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSEM micrographs of BiFeO\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e nanoparticles that were jet-milled and subsequently annealed.\u003c/strong\u003e The image reveals that the debris of smaller particles has largely disappeared, while significant agglomeration of the particles is still absent, as compared to the as-synthesized sample shown in Figure 2.\u003c/p\u003e","description":"","filename":"7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6470902/v1/d8b4e26c7c9f546057e5cae9.jpg"},{"id":81991029,"identity":"c07bc7c2-0c4b-4560-9ed6-521b137d2327","added_by":"auto","created_at":"2025-05-05 16:38:30","extension":"jpg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":36430,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eComparison of \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eM\u003c/strong\u003e\u003c/em\u003e\u003csub\u003e\u003cstrong\u003es\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e and \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eH\u003c/strong\u003e\u003c/em\u003e\u003csub\u003e\u003cstrong\u003ec\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e values achieved in BiFeO\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e from this study with those reported in previous studies. \u003c/strong\u003eAchieving simultaneous improvement in both \u003cem\u003eM\u003c/em\u003e\u003csub\u003es \u003c/sub\u003eand \u003cem\u003eH\u003c/em\u003e\u003csub\u003ec\u003c/sub\u003e in phase-pure BiFeO\u003csub\u003e3\u003c/sub\u003e while maintaining single-crystallinity has been a significant challenge. Jet-milling proves to be an effective method of achieving this requirement.\u003c/p\u003e","description":"","filename":"8.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6470902/v1/9cba9761ddb1b5128c790407.jpg"},{"id":89847144,"identity":"ab899d18-3d0c-42d6-bf7e-8b6772880bbd","added_by":"auto","created_at":"2025-08-25 16:41:13","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1559549,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6470902/v1/6f0194a1-bd76-4631-be02-ae1396fdca10.pdf"},{"id":81991061,"identity":"8dea5f65-5a61-48c0-a286-23f2bcfa21c2","added_by":"auto","created_at":"2025-05-05 16:38:32","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":557852,"visible":true,"origin":"","legend":"","description":"","filename":"SupportingInformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-6470902/v1/9a8b5c6f38149df1c66a8aae.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Achieving Ferromagnetism in Single-Crystalline Bismuth Ferrite Nanoparticles through Jet Milling","fulltext":[{"header":"Introduction","content":"\u003cp\u003eMultiferroics materials, which possess concurrent ferroelectric and antiferromagnetic orders, are a promising class of materials due to their potential applications in low-power consumption memory devices, sensing, actuation, and tunnel junction, etc [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Among the multiferroic material, the bismuth ferrite BiFeO\u003csub\u003e3\u003c/sub\u003e (BFO) is state of art material that is both magnetic and strongly ferroelectric at room temperature [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], This suggests that an electric field can change a material's magnetization, and a magnetic field can change a material's polarization. Due to the property's extreme rarity in the natural world, there has been a lot of interest in BiFeO\u003csub\u003e3\u003c/sub\u003e. The main effort in BiFeO\u003csub\u003e3\u003c/sub\u003e studies has been devoted to understanding the antiferromagnetic to ferromagnetic transition at room temperature [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eBiFeO\u003csub\u003e3\u003c/sub\u003e has Type 1 multiferroics with distorted rhombohedral perovskite structure. In bulk has ferroelectricity below Curie temperature (T\u003csub\u003eC\u003c/sub\u003e \u0026asymp; 830\u0026deg;C) and G-type antiferromagnetic ordering below Neel temperature (T\u003csub\u003eN\u003c/sub\u003e \u0026asymp; 370\u0026deg;C). It is known that ferroelectricity properties are due to Fe\u003csup\u003e3+\u003c/sup\u003e and Bi\u003csup\u003e3+\u003c/sup\u003e ions, which are displaced from their centrosymmetric positions resulting in spontaneous polarization along the direction [111] [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The Dzyaloshinskii-Moriya interaction (DMI) is a major factor in the antiferromagnetism of bismuth ferrite because of spin-orbit coupling and the lack of inversion symmetry in the crystal structure. The DMI introduces a term to the spin Hamiltonian that favors a canted alignment of neighboring spins, in contrast to the strictly antiparallel configuration typical of conventional antiferromagnetism. The DMI, arising from spin-orbit coupling in systems lacking inversion symmetry, promotes a non-collinear spin arrangement [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. In BiFeO\u003csub\u003e3\u003c/sub\u003e, this interaction stabilizes a long-wavelength cycloidal spin structure, where the spins rotate in a plane as they propagate through the material. The spin cycloid in BiFeO\u003csub\u003e3\u003c/sub\u003e exhibits a periodicity of about 62 nm, significantly influenced by the strength of the DMI. To modify the antiferromagnetic material such as BiFeO\u003csub\u003e3\u003c/sub\u003e to achieve ferromagnetism, the cycloid has to be broken and that can be typically achieved by strain, chemical doping, and formation of nanostructured materials [\u003cspan additionalcitationids=\"CR10 CR11 CR12\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The BFO ferromagnetic response has been studied using different methods, such as applying a high field, reducing the particle size, and doping. Doping in BFO samples is done in different ways (a) Chemical substitution of Bi\u003csup\u003e3+\u003c/sup\u003e ions in A sites by dopant ions like La\u003csup\u003e3+\u003c/sup\u003e, Sr\u003csup\u003e2+\u003c/sup\u003e, Er\u003csup\u003e3+\u003c/sup\u003e, Ba\u003csup\u003e2+\u003c/sup\u003e [\u003cspan additionalcitationids=\"CR15 CR16\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] (b) the B sites of Fe\u003csup\u003e3+\u003c/sup\u003e are chemically substituted by Ti\u003csup\u003e4+\u003c/sup\u003e, Nb\u003csup\u003e5+\u003c/sup\u003e o Ni\u003csup\u003e2+\u003c/sup\u003e [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e] (c) or co-doped by A and B positions with Zn\u003csup\u003e2+\u003c/sup\u003e and Ni\u003csup\u003e2+\u003c/sup\u003e [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDespite the application of several mentioned techniques, achieving a pure phase of BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles with a single crystalline nature while maintaining ferromagnetic properties remains challenging. The single crystallinity of BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles is crucial, and while this has been achieved in nanostructure preparations, scaling up the formation of such structures is difficult. Size reduction methods, such as ball milling, have been employed to induce ferromagnetic properties; however, this often results in polycrystallinity and the introduction of impurities [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Jet milling offers a viable alternative, which is using a high-velocity air or gas jet to pulverize particles to nanoscale dimensions, relying on particle-particle interactions to achieve size reduction. This technique is particularly effective for brittle materials like BiFeO\u003csub\u003e3\u003c/sub\u003e and significantly reduces contamination risks compared to ball milling, as the particle fracture process minimizes interactions with the milling medium and vial. Additionally, jet milling helps preserve the single crystallinity of the material [\u003cspan additionalcitationids=\"CR24\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn this study, we synthesized antiferromagnetic single-crystalline BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles using the sol-gel method. These nanoparticles were subsequently subjected to jet milling to reduce both agglomeration and particle size. Transmission Electron Microscopy (TEM) analyses were conducted to examine the crystallinity of the as-produced and jet-milled particles. The magnetic properties of these particles were also investigated, revealing some of the highest ferromagnetic properties directly obtained from the pure phase.\u003c/p\u003e"},{"header":"Experimental Section","content":"\u003cp\u003eThe process consisted of dissolving the bismuth nitrate [Bi(NO\u003csub\u003e3\u003c/sub\u003e).5H\u003csub\u003e2\u003c/sub\u003eO (SDFCL)] and iron nitrate [Fe(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e3\u003c/sub\u003e.9H\u003csub\u003e2\u003c/sub\u003eO (High purity laboratory chemicals pvt. Ltd)], in ethylene glycol (SRLchem) in required mole percentages. The solution was dissolved in a glass beaker over a magnetic stirring hot plate at 65°C covered with a watch glass to avoid evaporation and stirred continuously. Once all reactants were dissolved, the glass beaker was uncovered to allow evaporation and gel drying. The gel had a brown-yellow colour. The gel was washed three times with double distilled water, and acetone and collected by centrifuging at 10,000 rpm. Washing is done to remove the solvent (unreacted ethylene glycol removal). The samples were then oven-dried at 70°C, which allowed the powder to dry. Ground to a fine powder and transferred into a silica crucible, the samples were calcined at 600°C. After one hour, the furnace was turned off and allowed to cool naturally [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. These powders were then subjected to jet milling using compressed air in ambiance. About 5 grams of the BiFeO\u003csub\u003e3\u003c/sub\u003e powders were taken each time for milling at different pressures (2 bar, 4 bar, and 6 bar).\u003c/p\u003e \u003cp\u003eThe X-ray diffraction (XRD) pattern of the prepared sample was analysed using a Bruker D8 Advanced powdered diffractometer. ​The samples were distributed over carbon tape and subsequently gold coated and the scanning electron microscope imaging was performed using the Thermo Scientific APREO 2 FESEM. BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles were dispersed in ethanol and then subjected to ultrasonication for 10 to 20 minutes to ensure a uniform dispersion. Following this, a 1 µL droplet of the dispersion was cast onto a carbon-coated copper TEM grid. A plasma cleaning procedure was applied to the sample for one minute, after which the TEM grid, containing the sample, was positioned within a JEOL JEM F200 electron microscope equipped with a GIF Continuum K3 system. ​Imaging and EELS analysis were conducted at an operational voltage of 200 kV.​ The EELS spectra were recorded with a full-width half maxima (FWHM) of ~ 1.5 eV and a dispersion of 0.30 eV/channel. The convergence semi-angle and the collection semi-angle were measured to be 36.24 mrad and 29.60 mrad, respectively. The magnetic hysteresis was traced using a built-in vibrating sample magnetometer of the physical property measurement system (PPMS), procured from Dyna-Cool, USA with the applied magnetic field of ± 2 T.\u003c/p\u003e "},{"header":"Results and Discussions","content":"\u003cp\u003eThe X-ray diffraction pattern of the as-synthesized BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles is shown in Fig.\u0026nbsp;1. The diffraction peaks observed correspond to the rhombohedral perovskite structure of BiFeO\u003csub\u003e3\u003c/sub\u003e with R3c space group [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. The sharpness of the peak suggests that the crystallinity in the sol-gel synthesized BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles. The samples were then subjected to jet milling at different pressures. The X-ray diffraction patterns of BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles subjected to jet milling at different pressures (4 bar and 6 bar) are shown in Fig.\u0026nbsp;1. Both XRD patterns display characteristic peaks corresponding to the rhombohedral perovskite structure of BiFeO\u003csub\u003e3\u003c/sub\u003e, consistent with the sol-gel synthesized samples.\u003c/p\u003e\u003cp\u003eThe SEM images and analyses for the as-synthesized BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles and the particles that are jet-milled at 4 bar pressure are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The as-prepared sample exhibits a collection of nanoparticles with irregular shapes and a significant degree of agglomeration, with many of them clustered together due to the inherent nature of the sol-gel synthesis process that involves calcination (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003eA-C). The particle size distribution is relatively broad, with particle lengths ranging from approximately 40 nm to 160 nm. The distribution shows a peak around 70–80 nm, indicating that the majority of the particles fall within this size range (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003eD). After subjecting the BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles to jet milling at a pressure of 4 bar (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003eE-G), significant changes in the particle morphology are observed. The jet milling process effectively reduced the size of the agglomerates (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003eE-F). Further, we can observe that the particles are separated and in addition, these individual particles are covered with a debris of fine particles (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003eG). The particle size distribution of the jet-milled BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles is presented in the histogram shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003eH. The jet-milled particles exhibit a size distribution mostly between 30 nm and 120 nm with the peak of distribution around 30 and 50 nm. The particle size has clearly shifted towards a smaller size in comparison to the as-synthesized samples. Note that after jet milling, the majority of the particles are less than 62 nm, the length of the spin cycloid [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe samples were then subjected to TEM studies to understand the crystal structure, crystallinity of the particles, and, the oxidation state of the ions in the samples.\u003c/p\u003e\u003cp\u003eFigure \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003eA shows the bright-field TEM image of the as-synthesized BiFeO\u003csub\u003e3\u003c/sub\u003e particles. The diffraction pattern was indexed and it shows that the particles are crystalline and they belong to the bismuth ferrite rhombohedral phase (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003eB). However, the diffraction pattern was not continuous and smooth indicating that the particles were larger in size. To investigate the crystallinity of the samples, high-resolution TEM imaging was performed (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003eC). The FFT taken from the entire region in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003eC is given in the inset of the image. We can see the single-crystal pattern that has been indexed to the zone axis [-2 -1 -1]. The planes corresponded to the rhombohedral structure of bismuth ferrite. The zoomed-in region from Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003eC is given in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003eD along with the indexing of the planes. Such high-resolution imaging has been performed on several other particles in the as-synthesized bismuth ferrite powder (Figure \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e) and the sample was found to be single-crystalline with larger crystallite size.\u003c/p\u003e\u003cp\u003eFurther, the samples jet-milled at 4 bar pressure are subjected to TEM studies (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e4\u003c/span\u003e). We can observe that the size of the particles in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e4\u003c/span\u003eA is smaller in size compared to Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003eA. Further, the diffraction rings are complete and well-defined in the jet-milled samples indicating that the crystallite size has reduced in the jet-milled samples (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e4\u003c/span\u003eB). It can be observed from the HRTEM and the corresponding FFT shown in the inset of Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e4\u003c/span\u003eC, single-crystalline nature of the samples is preserved in the jet-milled samples. Figure\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e4\u003c/span\u003eD corresponds to the inverse FFT of a region from Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e4\u003c/span\u003eC, highlighting the crystalline ordering of atomic planes in the milled samples. The single-crystalline nature of the milled particles were further confirmed through imaging multiple particles (Figure S2). This is one of the important benefits of utilizing jet milling technique in contrast to other pulverisation techniques, because of the fact that here the particle-particle interaction is happening. Furthermore, the brittle nature of bismuth ferrite facilitates the effective fragmentation of particles into smaller, uniform sizes during the milling process.\u003c/p\u003e\u003cp\u003eTo investigate the effect of jet milling on the magnetic properties of BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles, the samples were analyzed using a PPMS setup. Figure\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e5\u003c/span\u003e shows the magnetic properties for the as-synthesized and the particles that were jet milled at different pressures. Figure\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e5\u003c/span\u003eA shows the hysteresis loop for the as-synthesized BiFeO\u003csub\u003e3\u003c/sub\u003e sample, which exhibits very low magnetization and coercivity, typical of its antiferromagnetic nature. The low magnetic response confirms the purity and antiferromagnetic order of the as-synthesized BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eFigure \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e5\u003c/span\u003eB shows the magnetic behavior of BiFeO\u003csub\u003e3\u003c/sub\u003e samples subjected to jet milling at pressures of 2 bar, 4 bar, and 6 bar. The jet milling process significantly enhances the magnetic properties, particularly at higher milling pressures. The samples milled at 4 bar and 6 bar show a remarkable increase in saturation magnetization and coercivity, indicating a transition towards ferromagnetic behavior. The observed enhancement in magnetization is attributed to the disruption of the cycloidal spin structure due to the reduction in particle size achieved through jet milling (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe maximum magnetization obtained for the as-synthesized samples correspond to \u003cem\u003eM\u003c/em\u003e\u003csub\u003es\u003c/sub\u003e ~ 0.91 emu/g. The jet-milled samples exhibited a \u003cem\u003eM\u003c/em\u003e\u003csub\u003es\u003c/sub\u003e ~ 10 emu/g. Showing that the magnetization value has easily been increased about 10 times. This can be directly attributed to the reduced particle size in jet-milled samples where magnetization improves due to the contribution from uncompensated spins at the surface of the nanoparticles. By noting the coercivity (\u003cem\u003eH\u003c/em\u003e\u003csub\u003ec\u003c/sub\u003e) values, we obtained about 30 percent improvement. However, by noting the nature of the hysteresis loop, we can observe that the plot has a dip near zero magnetic field, indicating the possibility of contribution from the decomposed phase (Fig.\u0026nbsp;1). In order to understand the effect of particle size, we have taken the jet-milled samples and subjected to annealing at 400°C in ambient atmosphere for one hour of time. The samples were then furnace cooled. The magnetic hysteresis plots are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e6\u003c/span\u003e. The magnetic parameters for the as-synthesized, jet-milled and annealed samples after jet-milled bismuth ferrite powders are summarized in Table – I.\u003c/p\u003e\u003cp\u003eIt can be seen that the magnetization of the samples has come down to that nearly of the as-synthesized samples. However, the coercivity value is about 20 times higher in the jet-milled-annealed samples in comparison to the as-synthesized samples. SEM micrograph for one of the annealed samples (jet-milled at 4 bar and annealed at 400°C for 1 h) is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e7\u003c/span\u003e. It can be seen that the debris of smaller particles have become insignificant. However, the agglomeration of the particles is still not present (compare with Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe aggregation of nanoparticles significantly influences their magnetic properties. Strong aggregation can result in a more homogeneous magnetic environment, which reduces the distinct contributions of individual particles to coercivity [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. When the spacing between magnetic nanoparticles increases, the strength of interparticle interactions weakens, allowing the magnetic moments of individual particles to remain more independent. This independence is essential for preserving the anisotropic properties of each particle, which are critical for achieving and maintaining high coercivity [\u003cspan additionalcitationids=\"CR31 CR32 CR33 CR34 CR35 CR36\" citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e–\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e].\u003c/p\u003e\u003cp\u003e \u003cb\u003eTable I: Magnetic parameters for as-synthesized; jet-milled; annealed BiFeO\u003c/b\u003e \u003csub\u003e \u003cb\u003e3\u003c/b\u003e \u003c/sub\u003e \u003cb\u003enanoparticles\u003c/b\u003e\u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" 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\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e\u003ccolgroup cols=\"7\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eM\u003c/em\u003e\u003csub\u003es\u003c/sub\u003e @ 20 kOe\u003c/p\u003e \u003cp\u003e(emu/g)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eM\u003c/em\u003e\u003csub\u003er\u003c/sub\u003e (emu/g)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eM\u003c/em\u003e\u003csub\u003er\u003c/sub\u003e/\u003cem\u003eM\u003c/em\u003e\u003csub\u003es\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eH\u003c/em\u003e\u003csub\u003ec\u003c/sub\u003e\u003c/p\u003e \u003cp\u003e(Oe)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eM\u003c/em\u003e\u003csub\u003es\u003c/sub\u003e ratio\u003c/p\u003e \u003cp\u003e(as-synthesized) \u003cem\u003eVs.\u003c/em\u003e others\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003eH\u003c/em\u003e\u003csub\u003ec\u003c/sub\u003e ratio\u003c/p\u003e \u003cp\u003e(as-synthesized) \u003cem\u003eVs.\u003c/em\u003e others\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAs-synthesized\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.9\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.06\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.06\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eJet-milled@2 bar\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.4\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e95\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2.4\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eJet-milled@4 bar\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12.5\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1450\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e13.7\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e36.2\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eJet-milled@6 bar\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9.9\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3.3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1330\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e10.9\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e33.2\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eJet-milled@4 bar, Annealed\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.8\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.4\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e720\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eJet-milled@6 bar, Annealed\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1200\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.4\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn this study, we have synthesized single-crystalline BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles using the sol-gel method and subsequently enhanced their magnetic properties through jet milling. The primary focus was on understanding the impact of jet milling on the structural and magnetic characteristics of BiFeO\u003csub\u003e3\u003c/sub\u003e. The jet milling process effectively reduced the particle size and minimized agglomeration without compromising the single-crystalline nature of the BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles. A significant increase in both saturation magnetization and coercivity was observed in the jet-milled samples. The disruption of the cycloidal spin structure, along with the reduction in particle size and reduced agglomeration, have contributed to the observed transition from antiferromagnetic to ferromagnetic behavior. So far, achieving simultaneous increases in both magnetization and coercivity has been largely limited to composite materials [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. However, this is difficult to achieve in phase-pure bismuth ferrite samples. Our study demonstrates a significant enhancement in these properties in phase-pure BiFeO\u003csub\u003e3\u003c/sub\u003e, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e8\u003c/span\u003e, where our results are compared with those from other studies.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eDue to their phase-pure single crystallinity and enhanced ferromagnetic properties, these BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles have significant potential for applications in soft magnetics, magnetic electrocatalysts, photocatalysts, memory devices, and more. The minimal agglomeration of these particles also increases the availability of active sites, making them particularly effective for electrocatalytic applications. It is noteworthy that, unlike conventional pulverized milling, the jet milling process is significantly faster, requiring only about 60 seconds to mill 5 grams of BiFeO\u003csub\u003e3\u003c/sub\u003e. This makes jet milling a highly efficient method for enhancing the magnetization of materials. The results of this study suggest that jet milling could be a valuable technique for other ferroelectric, piezoelectric, and ferromagnetic materials, particularly those that are brittle in nature. This approach holds promise for the development of advanced materials with superior magnetic performance while preserving their crystalline structure.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eConflict of interest\u003c/h2\u003e \u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eEH and MS express their gratitude to the Science and Engineering Research Board - Start-up Research Grant (SRG/2023/001939) program for funding the research, and ATK thanks the Science and Engineering Research Board - National Post Doctoral Fellowship (PDF/2023/003946) fellowship for supporting this research work.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAuthor contribution EH organized the overall research and , AT did the prepared the BFO samples, and measured the properties and AS analyzed the TEM data, and ATK has written most of the manuscript. RS discussed the direction and schedule of the research with EH. PDB and RG designed the protocol of jet milling of as synthesized BFO samples.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe authors gratefully acknowledge the support provided by Office of Industrial Consultancy and Sponsored Research (IC\u0026amp;SR) and National Facility for Atom Probe Tomography (NFAPT) at Indian Institute of Technology Madras for facilitating our XRD, SEM, and TEM experiments. We extend our sincere thanks to Dr. Vijaya Raghavan for his assistance with the TEM experiments and to Mr. Srinivasan for conducting the SEM experiments.\u003c/p\u003e\u003ch2\u003eData availability\u003c/h2\u003e \u003cp\u003eData availability No datasets were generated or analysed during the current study.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eSaenrang W, Davidson BA, Maccherozzi F, Podkaminer JP, Johnson RD, Freeland JW, \u0026Iacute;\u0026ntilde;iguez J, Schad JL, Reierson KJCF, Vaz CAF, Howald L, Kim TH, Ryu S, van Veenendaal M, Dhesi SS, Rzchowski MS. Deterministic and robust room temperature exchange coupling in monodomain multiferroic BiFeO\u003csub\u003e3\u003c/sub\u003e heterostructures. \u003cem\u003eNat Commun.\u003c/em\u003e 2017;8:1\u0026ndash;8. https://doi.org/10.1038/s41467-017-01581-6.\u003c/li\u003e\n\u003cli\u003eCatalan G, Scott JF. 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A simple analytical model for magnetization and coercivity of hard/soft nanocomposite magnets. \u003cem\u003eSci Rep.\u003c/em\u003e 2017;7:1\u0026ndash;5. https://doi.org/10.1038/s41598-017-04632-6.\u003c/li\u003e\n\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":"journal-of-nanoparticle-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nano","sideBox":"Learn more about [Journal of Nanoparticle Research](http://link.springer.com/journal/11051)","snPcode":"11051","submissionUrl":"https://submission.nature.com/new-submission/11051/3","title":"Journal of Nanoparticle Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Bismuth ferrite, Jet milling, Nanoparticles, Single-crystalline, Size effect, Ferromagnetism","lastPublishedDoi":"10.21203/rs.3.rs-6470902/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6470902/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBismuth ferrite, a multiferroic material known for its associated ferroelectric and antiferromagnetic properties, holds significant potential for advanced applications in memory devices, sensors, and electrocatalysts. However, achieving a simultaneous increase in both magnetization and coercivity while preserving the material\u0026rsquo;s single-crystallinity has been a considerable challenge, especially in phase-pure bismuth ferrite. In this work, we synthesized phase-pure BiFeO\u003csub\u003e3\u003c/sub\u003e nanoparticles using the sol-gel method and subjected them to jet milling at varying pressures. Detailed electron microscopy studies demonstrate that the jet milling process maintains the single-crystalline nature of BiFeO\u003csub\u003e3\u003c/sub\u003e while significantly reducing the particle size. The jet-milled samples exhibited up to a 10 increase in magnetization (~\u0026thinsp;10 emu/g) and a 30 times improvement in coercivity (\u0026gt;\u0026thinsp;1000 Oe) compared to the as-synthesized samples. This enhancement is attributed to the disruption of the cycloidal spin structure due to the reduced crystallite size and reduced agglomeration of the particles. This work presents jet milling as an effective technique for enhancing the magnetic performance of BiFeO\u003csub\u003e3\u003c/sub\u003e, with potential applications in multiferroic devices and other advanced technologies.\u003c/p\u003e","manuscriptTitle":"Achieving Ferromagnetism in Single-Crystalline Bismuth Ferrite Nanoparticles through Jet Milling","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-05 16:38:20","doi":"10.21203/rs.3.rs-6470902/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-06-04T05:11:58+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-26T18:49:26+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-20T17:24:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"146209681358963616059051267751536330478","date":"2025-05-09T14:04:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"165889766378173631135341010336391570669","date":"2025-04-30T08:46:28+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-04-30T06:52:09+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-04-20T20:34:38+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-17T12:50:17+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Nanoparticle Research","date":"2025-04-17T10:26:36+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-nanoparticle-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nano","sideBox":"Learn more about [Journal of Nanoparticle Research](http://link.springer.com/journal/11051)","snPcode":"11051","submissionUrl":"https://submission.nature.com/new-submission/11051/3","title":"Journal of Nanoparticle Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"a7b59836-9399-466a-8cc9-a80d3d2c4280","owner":[],"postedDate":"May 5th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-08-25T16:31:45+00:00","versionOfRecord":{"articleIdentity":"rs-6470902","link":"https://doi.org/10.1007/s11051-025-06413-z","journal":{"identity":"journal-of-nanoparticle-research","isVorOnly":false,"title":"Journal of Nanoparticle Research"},"publishedOn":"2025-08-18 16:28:57","publishedOnDateReadable":"August 18th, 2025"},"versionCreatedAt":"2025-05-05 16:38:20","video":"","vorDoi":"10.1007/s11051-025-06413-z","vorDoiUrl":"https://doi.org/10.1007/s11051-025-06413-z","workflowStages":[]},"version":"v1","identity":"rs-6470902","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6470902","identity":"rs-6470902","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}