{"paper_id":"131fb69e-4baa-4dc2-a819-8863e78e1ad9","body_text":"Chemical- and hydrostatic-pressure-controlled metallization in NiS2−xSex | 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 Article Chemical- and hydrostatic-pressure-controlled metallization in NiS 2 − x Se x Tayyaba Hussain, Muhammad Nauman, Joonyoung Choi, Mariam Omran, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7784767/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 12 Mar, 2026 Read the published version in Scientific Reports → Version 1 posted 11 You are reading this latest preprint version Abstract External control parameters, including pressure, chemical substitution, and temperature, play a central role in modulating the electronic states of strongly correlated systems. In this study, we investigate the metal–insulator transition (MIT) in NiS 2 − x Se x under the combined influence of hydrostatic and chemical pressure. In pure NiS 2 , the weak ferromagnetic transition temperature shifts in response to applied pressure. Metallization occurs at a relatively low pressure (1.3 kbar) for NiS 1.6 Se 0.4 , while lightly doped NiS 1.9 Se 0.1 requires higher pressure. At x = 0.5, a metallic state arises solely from chemical substitution, without requiring external pressure. These results underscore the dominant influence of chemical pressure over hydrostatic compression and enable the construction of a unified pressure–doping–temperature phase diagram. These findings offer new insights into correlation-driven MITs and may inform the rational design of functional Mott systems. Physical sciences/Chemistry Physical sciences/Materials science Physical sciences/Physics NiS2 − xSex metal–insulator transition Mott insulator chemical substitution hydrostatic pressure phase diagram Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 1. INTRODUCTION Strongly correlated electron systems offer a unique platform for investigating emergent phenomena driven by electron–electron interactions, including unconventional superconductivity, metal–insulator transitions (MITs), and exotic magnetic phases. Among such systems, transition-metal dichalcogenides, including CoS 2 , NiS 2 , and FeS 2 , have garnered considerable attention owing to their bandwidth-controlled Mott transitions [ 1 – 3 ], tunable magnetic ordering, and potential for ultrafast resistivity switching [ 4 – 6 ]. In these compounds, strong electron correlations markedly reshape both electronic band structures and magnetic responses [ 7 – 9 ]. Within this family, the NiS–NiSe 2 series serves as an ideal model system for probing correlation-driven MITs. Notably, it preserves a stable cubic pyrite structure across the full doping range, thereby enabling a clear investigation of correlation effects without structural complications [ 10 – 13 ]. Pure NiS 2 represents a prototypical Mott insulator wherein Ni 2+ ions (3d 8 ) feature partially filled e g orbitals that are strongly localized owing to Coulomb repulsion, resulting in an antiferromagnetic insulating (AFI) ground state at low temperatures. Substituting S with Se in NiS 2 − x Se x exerts chemical pressure by increasing the lattice constants and broadening the e g band, thereby enhancing orbital overlap and reducing electron localization [ 7 , 14 , 15 ]. Additional systematic Se substitution drives well-documented electronic and magnetic phase transitions. At a critical concentration of x ≈ 0.45, the system transitions from an AFI to an antiferromagnetic metallic (AFM) state; moreover, with further Se substitution ( x ≈ 1.0, NiSSe), it evolves into a paramagnetic metal while maintaining the cubic pyrite structure [ 15 , 16 ]. This progressive metallization is attributed to the greater orbital extension of Se–Se bonds compared with that of S–S bonds, which strengthens Ni–Se interactions and reduces effective Coulomb repulsion. Previous studies have extensively characterized the above transitions using transport analysis [ 17 ], neutron scattering measurements [ 18 – 20 ], and Mössbauer spectroscopy [ 10 , 21 ], highlighting the delicate balance between electron localization and itinerancy. Recent experimental advances, particularly in high-pressure approaches and spectroscopic methods, have uncovered subtle magnetic transitions and nontrivial metallic states that challenge conventional band theory [ 14 , 22 ]. Notably, hydrostatic pressure serves as a powerful tuning parameter: in pure NiS 2 , metallization emerges above 2.6 GPa as pressure widens the Ni d-band and enhances electron delocalization [ 10 , 15 , 17 , 21 , 22 ]. Although sulfur dimers remain structurally rigid under pressure, increased inter-dimer hopping effectively bridges isolated bands, thereby driving the MIT. Thus, the combined application of chemical substitution and hydrostatic pressure offers an effective dual strategy for tuning the ground state of NiS 2 − x Se x , establishing it as a robust platform for investigating Mott physics [ 23 ]. Given this background, in the present study, we systematically investigate NiS 2 − x Se x (0 ≤ x ≤ 0.5) under the combined influence of chemical substitution and hydrostatic pressure. By employing these dual perturbations, an approach not comprehensively explored in previous studies, we tune the interatomic spacing and conduction bandwidth, thereby enabling precise control over the MIT. We construct a unified pressure–doping–temperature phase diagram that delineates the respective contributions of chemical substitution and hydrostatic pressure, offering new insights into Mott insulators and correlation-driven electronic phenomena. 2. RESULTS The evolution of electronic phases in NiS 2 − x Se x under the combined effects of chemical doping and hydrostatic pressure reveals a coherent framework for understanding correlation-driven transitions. The cubic pyrite structure of NiS 2 , comprising Ni (blue spheres) and S/Se (yellow spheres) (Fig. 1 inset), is retained across all doping levels, thus allowing a direct investigation of electronic effects without structural complications. In the low-doping regime (0 ≤ x ≤ 0.4), NiS 2 − x Se x displays insulating behavior over a wide temperature range, with weak ferromagnetic (WFM) ordering manifesting at low temperatures. The MIT emerges near the critical concentration ( x cr ≈ 0.45), where resistivity becomes nearly temperature-independent and the activation energy gap collapses. Within the intermediate doping range (0.51 ≤ x ≤ 0.58), resistivity declines, indicating a progressive weakening of insulating behavior. Beyond this range, at higher doping levels ( x ≥ 0.6), the system exhibits a robust metallic character, as demonstrated by a monotonic decrease in resistivity with decreasing temperature [ 24 , 25 ]. These trends are consolidated in the temperature–doping phase diagram (Fig. 1 ), which presents our results (solid circles) alongside those from earlier studies [ 19 , 23 , 24 , 26 ]. In parallel, Fig. 2 presents the influence of hydrostatic pressure on the electronic transport behavior of undoped NiS 2 . Across applied pressures up to 14.4 kbar, the material retains its insulating nature, with resistivity curves displaying distinct local maxima between 50 and 150 K. The corresponding derivative curves (Fig. 2 inset) reveal sharp anomalies near 20–30 K, in agreement with earlier reports of WFM ordering [ 11 ]. To elucidate the combined effects of chemical doping and pressure-induced metallization, single crystals of NiS 2 − x Se x ( x = 0.1, 0.4, 0.5) were systematically analyzed. Stoichiometric incorporation of Se was confirmed through energy-dispersive X-ray spectroscopy. As depicted in Fig. 3 (a), the lightly doped compound NiS 1.9 Se 0.1 displays insulating behavior, with resistivity in the range of 10 3 –10 4 Ω·cm, in agreement with reported values for comparable compositions [ 4 ]. With increasing pressure, an MIT emerges near 7.5 kbar, marked by a pronounced drop in resistivity. Beyond this critical threshold, the transition temperature progressively shifts to higher values, and the resistivity curves exhibit a broad maximum between 30 and 80 K, followed by a marked decrease at lower temperatures. NiS 1.6 Se 0.4 also exhibits insulating behavior at ambient pressure, as presented in Fig. 3 (b). Upon cooling, the resistivity increases exponentially, presenting a local maximum between 40 and 60 K, followed by a further rise to a peak value of ~ 8000 Ω. Earlier reports indicate that NiS 2 − x Se x ( x = 0.4) undergoes an MIT at 1.6 kbar [ 5 ]. In this study, however, the corresponding metallization is observed at a lower pressure of 1.3 kbar, underscoring the compound’s sensitivity to the combined influence of hydrostatic and chemical pressures. As pressure increases further, the peak resistance decreases, and the MIT shifts toward higher temperatures. The step-like decrease in low-temperature resistance is attributed to a mixed state wherein metallic and insulating regions coexist. 3. DISCUSSION To analyze the insulating regime, temperature-dependent resistivity was fitted using the thermal activation model over the 125–300 K range: $$\\:\\rho\\:\\left(T\\right)=\\rho\\:\\left(0\\right){e}^{\\left(\\frac{{E}_{g}}{2{k}_{B}T}\\right)}.$$ 1 Here, E g denotes the band gap, k B is the Boltzmann constant, and ρ represents resistivity. Figure 4 presents E g as a function of pressure for undoped samples. The extracted values demonstrate good agreement with those reported in previous studies [ 2 , 13 ]. For both Se-doped and undoped NiS 2 samples, E g decreases progressively with increasing pressure. Among the two perturbations, chemical pressure exerts a substantially stronger influence on E g reduction than hydrostatic pressure alone. For instance, under x = 0.1 Se substitution, the E g of NiS 2 at ambient pressure is reduced by nearly half, while that of pure NiS 2 at 15 kbar becomes nearly identical to that of the x = 0.1 sample under ambient conditions. This pronounced reduction is attributed to the larger atomic radius of Se relative to that of S, consistent with previous reports [ 7 ]. Meanwhile, NiS 1.5 Se 0.5 already exhibits a chemically induced metallic state below 80 K, even at ambient pressure, as illustrated in Fig. 5 . This behavior originates from the greater radial extension of Se p orbitals compared to those of S, which broadens the electronic bandwidth and suppresses the insulating state. A comparable trend is observed in the (V 1 − x Ti x ) 2 O 3 system, where increasing Ti content induces an MIT, which is, however, discontinuous [ 6 ]. For NiS 1.5 Se 0.5 , hydrostatic pressures up to 7.2 kbar shift the MIT temperature toward room temperature. At ambient pressure, the residual resistance is lower than that observed under higher pressure. Meanwhile, the resistivity peak broadens progressively with increasing pressure and eventually flattens at the highest values. To contextualize these observations, we examined the phase diagram as a function of both hydrostatic pressure and Se composition. In the temperature–composition ( T – x ) phase diagram, the weak ferromagnetic insulating (WFI) phase emerges at low temperatures on the lightly doped side, transitions to an AFI phase at intermediate temperatures, and ultimately evolves into a paramagnetic insulator phase at higher temperatures. Conversely, at higher doping levels, the AFM and paramagnetic metallic phases become prominent. Pure NiS 2 lies within the WFI region, compositions with 0.1 ≤ x ≤ 0.4 occupy the AFI region, and the MIT occurs near x = 0.5. The temperature–pressure ( T – P ) phase diagram indicates that pure NiS 2 exhibits an increase in the weak ferromagnetic transition temperature ( T WF ) with increasing pressure, consistent with earlier reports [ 27 ]. This compound also displays a large entropy change at the WF transition, leading to strong magnon–phonon coupling, which is believed to contribute to the stabilization of complex spin structures [ 27 ]. A decrease in the antiferromagnetic insulating transition temperature ( T AFI ) with pressure has also been reported [ 19 ], persisting up to the MIT and vanishing in the metallic regime. For x = 0.1, the MIT emerges within the AFM state at ∼7.5 kbar, with the transition temperature ( T MIT ) increasing further under higher pressure up to 9.4 kbar. At higher Se content ( x = 0.4), the MIT occurs at a much lower pressure of ∼1.3 kbar. This pronounced shift reflects the enhanced chemical pressure arising from the larger radial extension of Se p orbitals compared to those of S. 4. CONCLUSIONS This study demonstrates that the combined application of chemical substitution and hydrostatic pressure offers a systematic means to modulate the MIT in NiS 2 − x Se x . By extending the analysis over a broad range of compositions and pressures, we construct a comprehensive pressure–composition–temperature phase diagram capturing the delicate interplay between electron localization and itinerant behavior. Although phase diagrams for NiS 2 − x Se x have been reported previously, our results integrate the effects of two distinct tuning parameters within a unified framework, enabling a more quantitative comparison between chemical substitution and hydrostatic pressure. This unified representation demonstrates that chemical pressure narrows the gap and promotes metallization more effectively than hydrostatic compression, underscoring the crucial roles of orbital overlap and lattice expansion in correlation-driven transitions. In addition to clarifying the long-standing issue of pressure- and doping-induced metallization in pyrite systems, our study introduces a transferable framework for other Mott insulators where multiple control parameters act simultaneously. Collectively, these findings highlight the importance of constructing multidimensional phase diagrams to disentangle competing interactions and to guide the rational design of functional correlated materials. 5. MATERIALS AND METHODS High-quality single crystals of NiS 2 − x Se x (0 ≤ x ≤ 0.5) were synthesized using a conventional chemical vapor transport technique. Hydrostatic pressures up to 14 kbar were applied with a piston-type Be–Cu pressure cell, and the internal pressure was monitored simultaneously using manganin and lead manometers. The resistance of manganin d R / d P ≈ R 0 ∼ 2.48 Ω bar − 1 ) and the superconducting transition temperature of lead (d Tc /d P = − 3.61 × 10 − 5 K bar − 1 ) served as pressure gauges. Electrical transport measurements under pressure were conducted using a standard four-probe configuration, and the resistance was measured as a function of temperature down to 6 K in a closed-cycle refrigerator with an excitation current of approximately 1 µA. Declarations FUNDING This work was supported by the National Research Foundation of Korea (NRF) under Grant Nos. RS-2024-00337640 and RS-2023-00301914. AUTHOR CONTRIBUTIONS T.H. and Y.J. designed the experiments. G.H and C.K synthesized the single crystals. T.H, M.N., J.C, M.O, W.K, and Y.J carried out measurements of physical properties. T.H and Y.J analyzed the data and prepared the manuscript. All the authors have read and approved the fnal version of the manuscript. DATA AVAILABILITY STATEMENT The data supporting the findings of this research are available within the article. COMPETING INTERESTS The authors declare no competing interests. References Jarrett, H. et al. Evidence for itinerant d-electron ferro-magnetism. Physical Review Letters 21 , 617 (1968). Kautz, R. et al. Electrical and optical properties of NiS 2 . Physical Review B 6 , 2078 (1972). Ziat, Y. et al. First-principles investigation of the electronic and optical properties of al-doped FeS 2 pyrite for photovoltaic applications. Optical and Quantum Electronics 48 (2016). Yao, X. et al. Electrical properties of NiS 2 −x Se x single crystals: From mott insulator to paramagnetic metal. Physical Review B 54 , 17469 (1996). Husmann, A. et al. Dynamical signature of the motthubbard transition in Ni(S,Se) 2 . Science 274 , 1874 (1996). Carter, S. et al. Effect of correlations and disorder on electron states in the mott-hubbard insulator V 2 O 3 . Physical Review B 43 , 607 (1991). Sheng, Q. et al. Two-step mott transition in Ni(S,Se) 2 : µ sr studies and charge-spin percolation model. Physical Review Research 4 , 033172 (2022). Hussain, T. et al. Pressure-induced metal–insulator transitions in chalcogenide NiS 2 −x Se x . Physica B: Condensed Matter 536 , 235–238 (2018). Nauman, M. et al. In-plane magnetic anisotropy in strontium iridate Sr 2 IrO 4 . Physical Review B 96 , 155102 (2017). Krill, G. et al. Electronic and magnetic properties of the pyrite-structure compound NiS 2 : influence of vacancies and copper impurities. Journal of Physics C: Solid State Physics 9 , 761 (1976). Friedemann, S. et al. Large fermi surface of heavy electrons at the border of mott insulating state in NiS 2 . Scientific Reports 6 (2016). Sekine, Y. et al. Effect of pressure on transport properties of Ni(S 1 −x Se x ) 2 . 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Matsuura, M. et al. Magnetic phase diagram and metalinsulator transition of NiS 2 −x Se x . Journal of the Physical Society of Japan 69 , 1503–1508 (2000). Yano, S. et al. Magnetic structure of NiS 2 −x Se x . Physical Review B 93 , 024409 (2016). Nishihara, Y., Ogawa, S. & Waki, S. Mössbauer study of 57 Fe doped in NiS 2 −x Se x . Journal of Physics C: Solid State Physics 11 , 1935 (1978). Yasui, Y. et al. Closing of the mott gap near step edges in NiS 2 . Physical Review B 110 , 045139 (2024). Marini, C. Pressure-induced metallization process in strongly correlated electron systems (2010). Czjzek, G. et al. An investigation of magnetic structures and phase transitions in NiS 2 −x Se x by 61 Ni-mössbauer spectroscopy. Journal of Magnetism and Magnetic Materials 3 , 58–60 (1976). Marini, C. Pressure-induced metallization process in Strongly Correlated Electron Systems . Ph.D. thesis, Roma Tre University (2000). Yao, X. & Honig, J. Growth of nickel dichalcogenides crystals with pyrite structure from tellurium melts. Materials Research Bulletin 29 , 709–716 (1994). Mori, N. & Watanabe, T. Pressure effects on the magnetic transition temperatures of NiS 2 . Solid State Communications 27 , 567–569 (1978). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 12 Mar, 2026 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 17 Jan, 2026 Reviews received at journal 15 Jan, 2026 Reviewers agreed at journal 27 Dec, 2025 Reviews received at journal 22 Dec, 2025 Reviewers agreed at journal 29 Nov, 2025 Reviewers agreed at journal 28 Nov, 2025 Reviewers invited by journal 26 Oct, 2025 Editor invited by journal 10 Oct, 2025 Editor assigned by journal 07 Oct, 2025 Submission checks completed at journal 07 Oct, 2025 First submitted to journal 05 Oct, 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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15:28:12\",\"extension\":\"xml\",\"order_by\":15,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":66598,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"8150b5db28da4d359a3cb3464983fb3d1structuring.xml\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7784767/v1/a0adccb5607c064eda1001db.xml\"},{\"id\":95227690,\"identity\":\"39ba0f3c-cc8f-48da-8fd0-ff9b1dcbf35d\",\"added_by\":\"auto\",\"created_at\":\"2025-11-05 16:32:45\",\"extension\":\"html\",\"order_by\":16,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":74851,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"earlyproof.html\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7784767/v1/aab59b4d1d8cdf13c190137d.html\"},{\"id\":95218275,\"identity\":\"d9ad6653-b84f-4b63-8ed1-5969cdf7e0ca\",\"added_by\":\"auto\",\"created_at\":\"2025-11-05 15:28:12\",\"extension\":\"png\",\"order_by\":1,\"title\":\"Figure 1\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":48563,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003ePhase diagram constructed based on data from previous studies [19, 26]. Solid black, red, and blue circles represent data from the present study. WF: weak ferromagnetic; AFI: antiferromagnetic insulator; PI: paramagnetic insulator; AFM: antiferromagnetic metal; PM: paramagnetic metal. The dashed lines denote crossover regions. Inset: crystal structure of NiS\\u003csub\\u003e2\\u003c/sub\\u003e.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"1.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7784767/v1/bf1ea0469609c55c85771001.png\"},{\"id\":95218276,\"identity\":\"b8cb363a-c12e-4007-b3d8-09bc4a3b6998\",\"added_by\":\"auto\",\"created_at\":\"2025-11-05 15:28:12\",\"extension\":\"png\",\"order_by\":2,\"title\":\"Figure 2\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":74407,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eTemperature-dependent resistance of NiS\\u003csub\\u003e2\\u003c/sub\\u003e at various applied pressures. Inset: temperature derivative d\\u003csub\\u003eR\\u003c/sub\\u003e/d\\u003csub\\u003eT\\u003c/sub\\u003e, showing distinct low-temperature kinks at all pressures.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"2.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7784767/v1/e3c325550aefff14f541914f.png\"},{\"id\":95218277,\"identity\":\"c20ee5de-0de7-4a4d-b696-2517368f55a7\",\"added_by\":\"auto\",\"created_at\":\"2025-11-05 15:28:12\",\"extension\":\"png\",\"order_by\":3,\"title\":\"Figure 3\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":129519,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003e(a) Temperature-dependent resistivity ρ(T) of NiS\\u003csub\\u003e1.9\\u003c/sub\\u003eSe\\u003csub\\u003e0.1\\u003c/sub\\u003e, showing insulating behavior at low pressures and an MIT near ~7.5 kbar. (b) Temperature-dependent resistance \\u003cem\\u003eR\\u003c/em\\u003e(\\u003cem\\u003eT\\u003c/em\\u003e) of NiS\\u003csub\\u003e1.6\\u003c/sub\\u003eSe\\u003csub\\u003e0.4\\u003c/sub\\u003e, demonstrating insulating behavior at ambient pressure and an MIT near ~1.3 kbar.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"3.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7784767/v1/c6f65b1ed095400780c2e66e.png\"},{\"id\":95218279,\"identity\":\"b9f812ea-7365-42e9-82b3-986e2dedfe28\",\"added_by\":\"auto\",\"created_at\":\"2025-11-05 15:28:12\",\"extension\":\"png\",\"order_by\":4,\"title\":\"Figure 4\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":25773,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003ePressure dependence of the band gap (\\u003cem\\u003eE\\u003c/em\\u003e\\u003csub\\u003eg\\u003c/sub\\u003e) for pure and Se-doped NiS\\u003csub\\u003e2−\\u003c/sub\\u003e\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003cem\\u003ex\\u003c/em\\u003e samples, as extracted from equation (1).\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"4.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7784767/v1/8a2c06ee38e7b2401564dd89.png\"},{\"id\":95218296,\"identity\":\"59a4be45-19d0-44d7-8523-62a75f6e96ca\",\"added_by\":\"auto\",\"created_at\":\"2025-11-05 15:28:14\",\"extension\":\"png\",\"order_by\":5,\"title\":\"Figure 5\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":48658,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eTemperature-dependent resistance of NiS\\u003csub\\u003e1.5\\u003c/sub\\u003eSe\\u003csub\\u003e0.5 \\u003c/sub\\u003eat ambient and elevated pressures.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"5.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7784767/v1/ea2d3a4291a00f4558836d78.png\"},{\"id\":95218284,\"identity\":\"bb180b72-a0e2-4bef-bc16-8e93ab27c55f\",\"added_by\":\"auto\",\"created_at\":\"2025-11-05 15:28:12\",\"extension\":\"png\",\"order_by\":6,\"title\":\"Figure 6\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":52635,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003ePressure–composition–temperature phase diagram of NiS\\u003csub\\u003e2−\\u003c/sub\\u003e\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003e (0 ≤ \\u003cem\\u003ex\\u003c/em\\u003e ≤ 0.5) under hydrostatic pressure.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"6.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7784767/v1/b3f8347cc49acab482d78a17.png\"},{\"id\":104739608,\"identity\":\"ce5d26d7-78d2-4c70-a5c8-c2c6aa629624\",\"added_by\":\"auto\",\"created_at\":\"2026-03-16 16:10:00\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":827811,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7784767/v1/3fc7b1e8-990b-40b3-b220-907fd47f9ad5.pdf\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"\\u003cp\\u003eChemical- and hydrostatic-pressure-controlled metallization in NiS\\u003csub\\u003e2\\u003c/sub\\u003e−\\u003csub\\u003ex\\u003c/sub\\u003eSe\\u003csub\\u003ex\\u003c/sub\\u003e\\u003c/p\\u003e\",\"fulltext\":[{\"header\":\"1. INTRODUCTION\",\"content\":\"\\u003cp\\u003eStrongly correlated electron systems offer a unique platform for investigating emergent phenomena driven by electron\\u0026ndash;electron interactions, including unconventional superconductivity, metal\\u0026ndash;insulator transitions (MITs), and exotic magnetic phases. Among such systems, transition-metal dichalcogenides, including CoS\\u003csub\\u003e2\\u003c/sub\\u003e, NiS\\u003csub\\u003e2\\u003c/sub\\u003e, and FeS\\u003csub\\u003e2\\u003c/sub\\u003e, have garnered considerable attention owing to their bandwidth-controlled Mott transitions [\\u003cspan additionalcitationids=\\\"CR2\\\" citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e], tunable magnetic ordering, and potential for ultrafast resistivity switching [\\u003cspan additionalcitationids=\\\"CR5\\\" citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e]. In these compounds, strong electron correlations markedly reshape both electronic band structures and magnetic responses [\\u003cspan additionalcitationids=\\\"CR8\\\" citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e]. Within this family, the NiS\\u0026ndash;NiSe\\u003csub\\u003e2\\u003c/sub\\u003e series serves as an ideal model system for probing correlation-driven MITs. Notably, it preserves a stable cubic pyrite structure across the full doping range, thereby enabling a clear investigation of correlation effects without structural complications [\\u003cspan additionalcitationids=\\\"CR11 CR12\\\" citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003ePure NiS\\u003csub\\u003e2\\u003c/sub\\u003e represents a prototypical Mott insulator wherein Ni\\u003csup\\u003e2+\\u003c/sup\\u003e ions (3d\\u003csup\\u003e8\\u003c/sup\\u003e) feature partially filled e\\u003csub\\u003eg\\u003c/sub\\u003e orbitals that are strongly localized owing to Coulomb repulsion, resulting in an antiferromagnetic insulating (AFI) ground state at low temperatures. Substituting S with Se in NiS\\u003csub\\u003e2\\u0026thinsp;\\u0026minus;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003e exerts chemical pressure by increasing the lattice constants and broadening the e\\u003csub\\u003eg\\u003c/sub\\u003e band, thereby enhancing orbital overlap and reducing electron localization [\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e]. Additional systematic Se substitution drives well-documented electronic and magnetic phase transitions. At a critical concentration of \\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;\\u0026asymp;\\u0026thinsp;0.45, the system transitions from an AFI to an antiferromagnetic metallic (AFM) state; moreover, with further Se substitution (\\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;\\u0026asymp;\\u0026thinsp;1.0, NiSSe), it evolves into a paramagnetic metal while maintaining the cubic pyrite structure [\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR16\\\" class=\\\"CitationRef\\\"\\u003e16\\u003c/span\\u003e]. This progressive metallization is attributed to the greater orbital extension of Se\\u0026ndash;Se bonds compared with that of S\\u0026ndash;S bonds, which strengthens Ni\\u0026ndash;Se interactions and reduces effective Coulomb repulsion. Previous studies have extensively characterized the above transitions using transport analysis [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e], neutron scattering measurements [\\u003cspan additionalcitationids=\\\"CR19\\\" citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e], and M\\u0026ouml;ssbauer spectroscopy [\\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e], highlighting the delicate balance between electron localization and itinerancy. Recent experimental advances, particularly in high-pressure approaches and spectroscopic methods, have uncovered subtle magnetic transitions and nontrivial metallic states that challenge conventional band theory [\\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR22\\\" class=\\\"CitationRef\\\"\\u003e22\\u003c/span\\u003e]. Notably, hydrostatic pressure serves as a powerful tuning parameter: in pure NiS\\u003csub\\u003e2\\u003c/sub\\u003e, metallization emerges above 2.6 GPa as pressure widens the Ni d-band and enhances electron delocalization [\\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR22\\\" class=\\\"CitationRef\\\"\\u003e22\\u003c/span\\u003e]. Although sulfur dimers remain structurally rigid under pressure, increased inter-dimer hopping effectively bridges isolated bands, thereby driving the MIT. Thus, the combined application of chemical substitution and hydrostatic pressure offers an effective dual strategy for tuning the ground state of NiS\\u003csub\\u003e2\\u0026thinsp;\\u0026minus;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003e, establishing it as a robust platform for investigating Mott physics [\\u003cspan citationid=\\\"CR23\\\" class=\\\"CitationRef\\\"\\u003e23\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003eGiven this background, in the present study, we systematically investigate NiS\\u003csub\\u003e2\\u0026thinsp;\\u0026minus;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003e (0\\u0026thinsp;\\u0026le;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;\\u0026le;\\u0026thinsp;0.5) under the combined influence of chemical substitution and hydrostatic pressure. By employing these dual perturbations, an approach not comprehensively explored in previous studies, we tune the interatomic spacing and conduction bandwidth, thereby enabling precise control over the MIT. We construct a unified pressure\\u0026ndash;doping\\u0026ndash;temperature phase diagram that delineates the respective contributions of chemical substitution and hydrostatic pressure, offering new insights into Mott insulators and correlation-driven electronic phenomena.\\u003c/p\\u003e\"},{\"header\":\"2. RESULTS\",\"content\":\"\\u003cp\\u003eThe evolution of electronic phases in NiS\\u003csub\\u003e2\\u0026thinsp;\\u0026minus;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003e under the combined effects of chemical doping and hydrostatic pressure reveals a coherent framework for understanding correlation-driven transitions. The cubic pyrite structure of NiS\\u003csub\\u003e2\\u003c/sub\\u003e, comprising Ni (blue spheres) and S/Se (yellow spheres) (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e inset), is retained across all doping levels, thus allowing a direct investigation of electronic effects without structural complications. In the low-doping regime (0\\u0026thinsp;\\u0026le;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;\\u0026le;\\u0026thinsp;0.4), NiS\\u003csub\\u003e2\\u0026thinsp;\\u0026minus;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003e displays insulating behavior over a wide temperature range, with weak ferromagnetic (WFM) ordering manifesting at low temperatures. The MIT emerges near the critical concentration (\\u003cem\\u003ex\\u003c/em\\u003e\\u003csub\\u003ecr\\u003c/sub\\u003e \\u0026asymp; 0.45), where resistivity becomes nearly temperature-independent and the activation energy gap collapses. Within the intermediate doping range (0.51\\u0026thinsp;\\u0026le;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;\\u0026le;\\u0026thinsp;0.58), resistivity declines, indicating a progressive weakening of insulating behavior. Beyond this range, at higher doping levels (\\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;\\u0026ge;\\u0026thinsp;0.6), the system exhibits a robust metallic character, as demonstrated by a monotonic decrease in resistivity with decreasing temperature [\\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e24\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e25\\u003c/span\\u003e]. These trends are consolidated in the temperature\\u0026ndash;doping phase diagram (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e), which presents our results (solid circles) alongside those from earlier studies [\\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR23\\\" class=\\\"CitationRef\\\"\\u003e23\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e24\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR26\\\" class=\\\"CitationRef\\\"\\u003e26\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\u003cp\\u003eIn parallel, Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e presents the influence of hydrostatic pressure on the electronic transport behavior of undoped NiS\\u003csub\\u003e2\\u003c/sub\\u003e. Across applied pressures up to 14.4 kbar, the material retains its insulating nature, with resistivity curves displaying distinct local maxima between 50 and 150 K. The corresponding derivative curves (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e inset) reveal sharp anomalies near 20\\u0026ndash;30 K, in agreement with earlier reports of WFM ordering [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\u003cp\\u003eTo elucidate the combined effects of chemical doping and pressure-induced metallization, single crystals of NiS\\u003csub\\u003e2\\u0026thinsp;\\u0026minus;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003e (\\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;=\\u0026thinsp;0.1, 0.4, 0.5) were systematically analyzed. Stoichiometric incorporation of Se was confirmed through energy-dispersive X-ray spectroscopy. As depicted in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e(a), the lightly doped compound NiS\\u003csub\\u003e1.9\\u003c/sub\\u003eSe\\u003csub\\u003e0.1\\u003c/sub\\u003e displays insulating behavior, with resistivity in the range of 10\\u003csup\\u003e3\\u003c/sup\\u003e\\u0026ndash;10\\u003csup\\u003e4\\u003c/sup\\u003e Ω\\u0026middot;cm, in agreement with reported values for comparable compositions [\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e]. With increasing pressure, an MIT emerges near 7.5 kbar, marked by a pronounced drop in resistivity. Beyond this critical threshold, the transition temperature progressively shifts to higher values, and the resistivity curves exhibit a broad maximum between 30 and 80 K, followed by a marked decrease at lower temperatures.\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\u003cp\\u003eNiS\\u003csub\\u003e1.6\\u003c/sub\\u003eSe\\u003csub\\u003e0.4\\u003c/sub\\u003e also exhibits insulating behavior at ambient pressure, as presented in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e(b). Upon cooling, the resistivity increases exponentially, presenting a local maximum between 40 and 60 K, followed by a further rise to a peak value of ~\\u0026thinsp;8000 Ω. Earlier reports indicate that NiS\\u003csub\\u003e2\\u0026thinsp;\\u0026minus;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003e (\\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;=\\u0026thinsp;0.4) undergoes an MIT at 1.6 kbar [\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e]. In this study, however, the corresponding metallization is observed at a lower pressure of 1.3 kbar, underscoring the compound\\u0026rsquo;s sensitivity to the combined influence of hydrostatic and chemical pressures. As pressure increases further, the peak resistance decreases, and the MIT shifts toward higher temperatures. The step-like decrease in low-temperature resistance is attributed to a mixed state wherein metallic and insulating regions coexist.\\u003c/p\\u003e\"},{\"header\":\"3. DISCUSSION\",\"content\":\"\\u003cp\\u003eTo analyze the insulating regime, temperature-dependent resistivity was fitted using the thermal activation model over the 125\\u0026ndash;300 K range:\\u003cdiv id=\\\"Equ1\\\" class=\\\"Equation\\\"\\u003e\\u003cdiv format=\\\"TEX\\\" class=\\\"mathdisplay\\\" id=\\\"FileID_Equ1\\\" name=\\\"EquationSource\\\"\\u003e\\n$$\\\\:\\\\rho\\\\:\\\\left(T\\\\right)=\\\\rho\\\\:\\\\left(0\\\\right){e}^{\\\\left(\\\\frac{{E}_{g}}{2{k}_{B}T}\\\\right)}.$$\\u003c/div\\u003e\\u003cdiv class=\\\"EquationNumber\\\"\\u003e1\\u003c/div\\u003e\\u003c/div\\u003e\\u003c/p\\u003e\\u003cp\\u003eHere, \\u003cem\\u003eE\\u003c/em\\u003e\\u003csub\\u003eg\\u003c/sub\\u003e denotes the band gap, k\\u003csub\\u003eB\\u003c/sub\\u003e is the Boltzmann constant, and \\u003cem\\u003eρ\\u003c/em\\u003e represents resistivity. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e presents \\u003cem\\u003eE\\u003c/em\\u003e\\u003csub\\u003eg\\u003c/sub\\u003e as a function of pressure for undoped samples. The extracted values demonstrate good agreement with those reported in previous studies [\\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\u003cp\\u003eFor both Se-doped and undoped NiS\\u003csub\\u003e2\\u003c/sub\\u003e samples, \\u003cem\\u003eE\\u003c/em\\u003e\\u003csub\\u003eg\\u003c/sub\\u003e decreases progressively with increasing pressure. Among the two perturbations, chemical pressure exerts a substantially stronger influence on \\u003cem\\u003eE\\u003c/em\\u003e\\u003csub\\u003eg\\u003c/sub\\u003e reduction than hydrostatic pressure alone. For instance, under \\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;=\\u0026thinsp;0.1 Se substitution, the \\u003cem\\u003eE\\u003c/em\\u003e\\u003csub\\u003eg\\u003c/sub\\u003e of NiS\\u003csub\\u003e2\\u003c/sub\\u003e at ambient pressure is reduced by nearly half, while that of pure NiS\\u003csub\\u003e2\\u003c/sub\\u003e at 15 kbar becomes nearly identical to that of the \\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;=\\u0026thinsp;0.1 sample under ambient conditions. This pronounced reduction is attributed to the larger atomic radius of Se relative to that of S, consistent with previous reports [\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e]. Meanwhile, NiS\\u003csub\\u003e1.5\\u003c/sub\\u003eSe\\u003csub\\u003e0.5\\u003c/sub\\u003e already exhibits a chemically induced metallic state below 80 K, even at ambient pressure, as illustrated in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e. This behavior originates from the greater radial extension of Se p orbitals compared to those of S, which broadens the electronic bandwidth and suppresses the insulating state. A comparable trend is observed in the (V\\u003csub\\u003e1\\u0026thinsp;\\u0026minus;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eTi\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003e)\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e3\\u003c/sub\\u003e system, where increasing Ti content induces an MIT, which is, however, discontinuous [\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e]. For NiS\\u003csub\\u003e1.5\\u003c/sub\\u003eSe\\u003csub\\u003e0.5\\u003c/sub\\u003e, hydrostatic pressures up to 7.2 kbar shift the MIT temperature toward room temperature. At ambient pressure, the residual resistance is lower than that observed under higher pressure. Meanwhile, the resistivity peak broadens progressively with increasing pressure and eventually flattens at the highest values.\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\u003cp\\u003eTo contextualize these observations, we examined the phase diagram as a function of both hydrostatic pressure and Se composition. In the temperature\\u0026ndash;composition (\\u003cem\\u003eT\\u003c/em\\u003e\\u0026ndash;\\u003cem\\u003ex\\u003c/em\\u003e) phase diagram, the weak ferromagnetic insulating (WFI) phase emerges at low temperatures on the lightly doped side, transitions to an AFI phase at intermediate temperatures, and ultimately evolves into a paramagnetic insulator phase at higher temperatures. Conversely, at higher doping levels, the AFM and paramagnetic metallic phases become prominent. Pure NiS\\u003csub\\u003e2\\u003c/sub\\u003e lies within the WFI region, compositions with 0.1\\u0026thinsp;\\u0026le;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;\\u0026le;\\u0026thinsp;0.4 occupy the AFI region, and the MIT occurs near \\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;=\\u0026thinsp;0.5. The temperature\\u0026ndash;pressure (\\u003cem\\u003eT\\u003c/em\\u003e\\u0026ndash;\\u003cem\\u003eP\\u003c/em\\u003e) phase diagram indicates that pure NiS\\u003csub\\u003e2\\u003c/sub\\u003e exhibits an increase in the weak ferromagnetic transition temperature (\\u003cem\\u003eT\\u003c/em\\u003e\\u003csub\\u003eWF\\u003c/sub\\u003e) with increasing pressure, consistent with earlier reports [\\u003cspan citationid=\\\"CR27\\\" class=\\\"CitationRef\\\"\\u003e27\\u003c/span\\u003e]. This compound also displays a large entropy change at the WF transition, leading to strong magnon\\u0026ndash;phonon coupling, which is believed to contribute to the stabilization of complex spin structures [\\u003cspan citationid=\\\"CR27\\\" class=\\\"CitationRef\\\"\\u003e27\\u003c/span\\u003e]. A decrease in the antiferromagnetic insulating transition temperature (\\u003cem\\u003eT\\u003c/em\\u003e\\u003csub\\u003eAFI\\u003c/sub\\u003e) with pressure has also been reported [\\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e], persisting up to the MIT and vanishing in the metallic regime. For \\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;=\\u0026thinsp;0.1, the MIT emerges within the AFM state at \\u0026sim;7.5 kbar, with the transition temperature (\\u003cem\\u003eT\\u003c/em\\u003e\\u003csub\\u003eMIT\\u003c/sub\\u003e) increasing further under higher pressure up to 9.4 kbar. At higher Se content (\\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;=\\u0026thinsp;0.4), the MIT occurs at a much lower pressure of \\u0026sim;1.3 kbar. This pronounced shift reflects the enhanced chemical pressure arising from the larger radial extension of Se p orbitals compared to those of S.\\u003c/p\\u003e\"},{\"header\":\"4. CONCLUSIONS\",\"content\":\"\\u003cp\\u003eThis study demonstrates that the combined application of chemical substitution and hydrostatic pressure offers a systematic means to modulate the MIT in NiS\\u003csub\\u003e2\\u0026thinsp;\\u0026minus;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003e. By extending the analysis over a broad range of compositions and pressures, we construct a comprehensive pressure\\u0026ndash;composition\\u0026ndash;temperature phase diagram capturing the delicate interplay between electron localization and itinerant behavior. Although phase diagrams for NiS\\u003csub\\u003e2\\u0026thinsp;\\u0026minus;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003e have been reported previously, our results integrate the effects of two distinct tuning parameters within a unified framework, enabling a more quantitative comparison between chemical substitution and hydrostatic pressure.\\u003c/p\\u003e\\u003cp\\u003eThis unified representation demonstrates that chemical pressure narrows the gap and promotes metallization more effectively than hydrostatic compression, underscoring the crucial roles of orbital overlap and lattice expansion in correlation-driven transitions. In addition to clarifying the long-standing issue of pressure- and doping-induced metallization in pyrite systems, our study introduces a transferable framework for other Mott insulators where multiple control parameters act simultaneously. Collectively, these findings highlight the importance of constructing multidimensional phase diagrams to disentangle competing interactions and to guide the rational design of functional correlated materials.\\u003c/p\\u003e\"},{\"header\":\"5. MATERIALS AND METHODS\",\"content\":\"\\u003cp\\u003eHigh-quality single crystals of NiS\\u003csub\\u003e2\\u0026thinsp;\\u0026minus;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003e (0\\u0026thinsp;\\u0026le;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;\\u0026le;\\u0026thinsp;0.5) were synthesized using a conventional chemical vapor transport technique. Hydrostatic pressures up to 14 kbar were applied with a piston-type Be\\u0026ndash;Cu pressure cell, and the internal pressure was monitored simultaneously using manganin and lead manometers. The resistance of manganin \\u003cem\\u003ed\\u003c/em\\u003e\\u003csub\\u003eR\\u003c/sub\\u003e/\\u003cem\\u003ed\\u003c/em\\u003e\\u003csub\\u003eP\\u003c/sub\\u003e \\u0026asymp; \\u003cem\\u003eR\\u003c/em\\u003e\\u003csub\\u003e0\\u003c/sub\\u003e \\u0026sim; 2.48 Ω bar \\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e) and the superconducting transition temperature of lead (d\\u003csub\\u003eTc\\u003c/sub\\u003e/d\\u003csub\\u003eP\\u003c/sub\\u003e\\u0026thinsp;=\\u0026thinsp;\\u0026minus;\\u0026thinsp;3.61 \\u0026times; 10\\u003csup\\u003e\\u0026minus;\\u0026thinsp;5\\u003c/sup\\u003e K bar \\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e) served as pressure gauges. Electrical transport measurements under pressure were conducted using a standard four-probe configuration, and the resistance was measured as a function of temperature down to 6 K in a closed-cycle refrigerator with an excitation current of approximately 1 \\u0026micro;A.\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cp\\u003e\\u003cstrong\\u003eFUNDING\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThis work was supported by the National Research Foundation of Korea (NRF) under Grant Nos. RS-2024-00337640 and RS-2023-00301914.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAUTHOR CONTRIBUTIONS\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eT.H. and Y.J. designed the experiments. G.H and C.K synthesized the single crystals. T.H, M.N., J.C, M.O, W.K, and Y.J carried out measurements of physical properties. T.H and Y.J analyzed the data and prepared the manuscript. All the authors have read and approved the fnal version of the manuscript.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eDATA AVAILABILITY STATEMENT\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe data supporting the findings of this research are available within the article.\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eCOMPETING INTERESTS\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe authors declare no competing interests.\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\n\\u003cli\\u003eJarrett, H. \\u003cem\\u003eet al. \\u003c/em\\u003eEvidence for itinerant d-electron ferro-magnetism. \\u003cem\\u003ePhysical Review Letters \\u003c/em\\u003e\\u003cstrong\\u003e21\\u003c/strong\\u003e, 617 (1968). \\u003c/li\\u003e\\n\\u003cli\\u003eKautz, R. \\u003cem\\u003eet al. \\u003c/em\\u003eElectrical and optical properties of NiS\\u003csub\\u003e2\\u003c/sub\\u003e. \\u003cem\\u003ePhysical Review B \\u003c/em\\u003e\\u003cstrong\\u003e6\\u003c/strong\\u003e, 2078 (1972).\\u003c/li\\u003e\\n\\u003cli\\u003eZiat, Y. \\u003cem\\u003eet al. \\u003c/em\\u003eFirst-principles investigation of the electronic and optical properties of al-doped FeS\\u003csub\\u003e2 \\u003c/sub\\u003epyrite for photovoltaic applications. \\u003cem\\u003eOptical and Quantum Electronics \\u003c/em\\u003e\\u003cstrong\\u003e48 \\u003c/strong\\u003e(2016). \\u003c/li\\u003e\\n\\u003cli\\u003eYao, X. \\u003cem\\u003eet al. \\u003c/em\\u003eElectrical properties of NiS\\u003csub\\u003e2\\u003cem\\u003e\\u0026minus;x\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003cem\\u003e\\u003csub\\u003ex \\u003c/sub\\u003e\\u003c/em\\u003esingle crystals: From mott insulator to paramagnetic metal. \\u003cem\\u003ePhysical Review B \\u003c/em\\u003e\\u003cstrong\\u003e54\\u003c/strong\\u003e, 17469 (1996).\\u003c/li\\u003e\\n\\u003cli\\u003eHusmann, A. \\u003cem\\u003eet al. \\u003c/em\\u003eDynamical signature of the motthubbard transition in Ni(S,Se)\\u003csub\\u003e2\\u003c/sub\\u003e. \\u003cem\\u003eScience \\u003c/em\\u003e\\u003cstrong\\u003e274\\u003c/strong\\u003e, 1874 (1996).\\u003c/li\\u003e\\n\\u003cli\\u003eCarter, S. \\u003cem\\u003eet al. \\u003c/em\\u003eEffect of correlations and disorder on electron states in the mott-hubbard insulator V\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e3\\u003c/sub\\u003e. \\u003cem\\u003ePhysical Review B \\u003c/em\\u003e\\u003cstrong\\u003e43\\u003c/strong\\u003e, 607 (1991).\\u003c/li\\u003e\\n\\u003cli\\u003eSheng, Q. \\u003cem\\u003eet al. \\u003c/em\\u003eTwo-step mott transition in Ni(S,Se)\\u003csub\\u003e2\\u003c/sub\\u003e: \\u003cem\\u003e\\u0026micro;\\u003c/em\\u003esr studies and charge-spin percolation model. \\u003cem\\u003ePhysical Review Research \\u003c/em\\u003e\\u003cstrong\\u003e4\\u003c/strong\\u003e, 033172 (2022).\\u003c/li\\u003e\\n\\u003cli\\u003eHussain, T. \\u003cem\\u003eet al. \\u003c/em\\u003ePressure-induced metal\\u0026ndash;insulator transitions in chalcogenide NiS\\u003csub\\u003e2\\u003cem\\u003e\\u0026minus;x\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003cem\\u003e\\u003csub\\u003ex\\u003c/sub\\u003e\\u003c/em\\u003e. \\u003cem\\u003ePhysica B: Condensed Matter \\u003c/em\\u003e\\u003cstrong\\u003e536\\u003c/strong\\u003e, 235\\u0026ndash;238 (2018).\\u003c/li\\u003e\\n\\u003cli\\u003eNauman, M. \\u003cem\\u003eet al. \\u003c/em\\u003eIn-plane magnetic anisotropy in strontium iridate Sr\\u003csub\\u003e2\\u003c/sub\\u003eIrO\\u003csub\\u003e4\\u003c/sub\\u003e. \\u003cem\\u003ePhysical Review B \\u003c/em\\u003e\\u003cstrong\\u003e96\\u003c/strong\\u003e, 155102 (2017).\\u003c/li\\u003e\\n\\u003cli\\u003eKrill, G. \\u003cem\\u003eet al. \\u003c/em\\u003eElectronic and magnetic properties of the pyrite-structure compound NiS\\u003csub\\u003e2\\u003c/sub\\u003e: influence of vacancies and copper impurities. \\u003cem\\u003eJournal of Physics C: Solid State Physics \\u003c/em\\u003e\\u003cstrong\\u003e9\\u003c/strong\\u003e, 761 (1976).\\u003c/li\\u003e\\n\\u003cli\\u003eFriedemann, S. \\u003cem\\u003eet al. \\u003c/em\\u003eLarge fermi surface of heavy electrons at the border of mott insulating state in NiS\\u003csub\\u003e2\\u003c/sub\\u003e. \\u003cem\\u003eScientific Reports \\u003c/em\\u003e\\u003cstrong\\u003e6 \\u003c/strong\\u003e(2016). \\u003c/li\\u003e\\n\\u003cli\\u003eSekine, Y. \\u003cem\\u003eet al. \\u003c/em\\u003eEffect of pressure on transport properties of Ni(S\\u003csub\\u003e1\\u003cem\\u003e\\u0026minus;x\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003cem\\u003e\\u003csub\\u003ex\\u003c/sub\\u003e\\u003c/em\\u003e)\\u003csub\\u003e2\\u003c/sub\\u003e. \\u003cem\\u003ePhysica B: Condensed Matter \\u003c/em\\u003e\\u003cstrong\\u003e237\\u003c/strong\\u003e, 148\\u0026ndash; 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Rubio, A. Electronic and magnetic properties of NiS\\u003csub\\u003e2\\u003c/sub\\u003e, NiSSe and NiSe\\u003csub\\u003e2 \\u003c/sub\\u003eby a combination of theoretical methods. \\u003cem\\u003eThe European Physical Journal B \\u003c/em\\u003e\\u003cstrong\\u003e85\\u003c/strong\\u003e, 1\\u0026ndash;10 (2012).\\u003c/li\\u003e\\n\\u003cli\\u003eMiyasaka, S. \\u003cem\\u003eet al. \\u003c/em\\u003eMetal-insulator transition and itinerant antiferromagnetism in NiS\\u003csub\\u003e2\\u003cem\\u003e\\u0026minus;x\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003cem\\u003e\\u003csub\\u003ex \\u003c/sub\\u003e\\u003c/em\\u003epyrite. \\u003cem\\u003eJournal of the Physical Society of Japan \\u003c/em\\u003e\\u003cstrong\\u003e69\\u003c/strong\\u003e, 3166\\u0026ndash;3169 (2000).\\u003c/li\\u003e\\n\\u003cli\\u003eMiyadai, T. \\u003cem\\u003eet al. \\u003c/em\\u003eMagnetic properties of pyrite type NiS\\u003csub\\u003e2\\u003cem\\u003e\\u0026minus;x\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003cem\\u003e\\u003csub\\u003ex\\u003c/sub\\u003e\\u003c/em\\u003e. \\u003cem\\u003eJournal of Magnetism and Magnetic Materials \\u003c/em\\u003e\\u003cstrong\\u003e31\\u003c/strong\\u003e, 337\\u0026ndash;338 (1983).\\u003c/li\\u003e\\n\\u003cli\\u003eMatsuura, M. \\u003cem\\u003eet al. \\u003c/em\\u003eMagnetic phase diagram and metalinsulator transition of NiS\\u003csub\\u003e2\\u003cem\\u003e\\u0026minus;x\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003cem\\u003e\\u003csub\\u003ex\\u003c/sub\\u003e\\u003c/em\\u003e. \\u003cem\\u003eJournal of the Physical Society of Japan \\u003c/em\\u003e\\u003cstrong\\u003e69\\u003c/strong\\u003e, 1503\\u0026ndash;1508 (2000).\\u003c/li\\u003e\\n\\u003cli\\u003eYano, S. \\u003cem\\u003eet al. \\u003c/em\\u003eMagnetic structure of NiS\\u003csub\\u003e2\\u003cem\\u003e\\u0026minus;x\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003cem\\u003e\\u003csub\\u003ex\\u003c/sub\\u003e\\u003c/em\\u003e. \\u003cem\\u003ePhysical Review B \\u003c/em\\u003e\\u003cstrong\\u003e93\\u003c/strong\\u003e, 024409 (2016).\\u003c/li\\u003e\\n\\u003cli\\u003eNishihara, Y., Ogawa, S. \\u0026amp; Waki, S. M\\u0026ouml;ssbauer study of \\u003csup\\u003e57\\u003c/sup\\u003eFe doped in NiS\\u003csub\\u003e2\\u003cem\\u003e\\u0026minus;x\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003cem\\u003e\\u003csub\\u003ex\\u003c/sub\\u003e\\u003c/em\\u003e. \\u003cem\\u003eJournal of Physics C: Solid State Physics \\u003c/em\\u003e\\u003cstrong\\u003e11\\u003c/strong\\u003e, 1935 (1978).\\u003c/li\\u003e\\n\\u003cli\\u003eYasui, Y. \\u003cem\\u003eet al. \\u003c/em\\u003eClosing of the mott gap near step edges in NiS\\u003csub\\u003e2\\u003c/sub\\u003e. \\u003cem\\u003ePhysical Review B \\u003c/em\\u003e\\u003cstrong\\u003e110\\u003c/strong\\u003e, 045139 (2024).\\u003c/li\\u003e\\n\\u003cli\\u003eMarini, C. Pressure-induced metallization process in strongly correlated electron systems (2010). \\u003c/li\\u003e\\n\\u003cli\\u003eCzjzek, G. \\u003cem\\u003eet al. \\u003c/em\\u003eAn investigation of magnetic structures and phase transitions in NiS\\u003csub\\u003e2\\u003cem\\u003e\\u0026minus;x\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003cem\\u003e\\u003csub\\u003ex \\u003c/sub\\u003e\\u003c/em\\u003eby \\u003csup\\u003e61\\u003c/sup\\u003eNi-m\\u0026ouml;ssbauer spectroscopy. \\u003cem\\u003eJournal of Magnetism and Magnetic Materials \\u003c/em\\u003e\\u003cstrong\\u003e3\\u003c/strong\\u003e, 58\\u0026ndash;60 (1976).\\u003c/li\\u003e\\n\\u003cli\\u003eMarini, C. \\u003cem\\u003ePressure-induced metallization process in Strongly Correlated Electron Systems\\u003c/em\\u003e. Ph.D. thesis, Roma Tre University (2000).\\u003c/li\\u003e\\n\\u003cli\\u003eYao, X. \\u0026amp; Honig, J. Growth of nickel dichalcogenides crystals with pyrite structure from tellurium melts. \\u003cem\\u003eMaterials Research Bulletin \\u003c/em\\u003e\\u003cstrong\\u003e29\\u003c/strong\\u003e, 709\\u0026ndash;716 (1994).\\u003c/li\\u003e\\n\\u003cli\\u003eMori, N. \\u0026amp; Watanabe, T. Pressure effects on the magnetic transition temperatures of NiS\\u003csub\\u003e2\\u003c/sub\\u003e. \\u003cem\\u003eSolid State Communications \\u003c/em\\u003e\\u003cstrong\\u003e27\\u003c/strong\\u003e, 567\\u0026ndash;569 (1978).\\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\":\"info@researchsquare.com\",\"identity\":\"scientific-reports\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"scirep\",\"sideBox\":\"Learn more about [Scientific Reports](http://www.nature.com/srep/)\",\"snPcode\":\"\",\"submissionUrl\":\"\",\"title\":\"Scientific Reports\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"stoa\",\"reportingPortfolio\":\"Scientific Reports\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":true},\"keywords\":\"NiS2 − xSex, metal–insulator transition, Mott insulator, chemical substitution, hydrostatic pressure, phase diagram\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-7784767/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-7784767/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003eExternal control parameters, including pressure, chemical substitution, and temperature, play a central role in modulating the electronic states of strongly correlated systems. In this study, we investigate the metal\\u0026ndash;insulator transition (MIT) in NiS\\u003csub\\u003e2\\u0026thinsp;\\u0026minus;\\u0026thinsp;\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003eSe\\u003csub\\u003e\\u003cem\\u003ex\\u003c/em\\u003e\\u003c/sub\\u003e under the combined influence of hydrostatic and chemical pressure. In pure NiS\\u003csub\\u003e2\\u003c/sub\\u003e, the weak ferromagnetic transition temperature shifts in response to applied pressure. Metallization occurs at a relatively low pressure (1.3 kbar) for NiS\\u003csub\\u003e1.6\\u003c/sub\\u003eSe\\u003csub\\u003e0.4\\u003c/sub\\u003e, while lightly doped NiS\\u003csub\\u003e1.9\\u003c/sub\\u003eSe\\u003csub\\u003e0.1\\u003c/sub\\u003e requires higher pressure. At \\u003cem\\u003ex\\u003c/em\\u003e\\u0026thinsp;=\\u0026thinsp;0.5, a metallic state arises solely from chemical substitution, without requiring external pressure. These results underscore the dominant influence of chemical pressure over hydrostatic compression and enable the construction of a unified pressure\\u0026ndash;doping\\u0026ndash;temperature phase diagram. These findings offer new insights into correlation-driven MITs and may inform the rational design of functional Mott systems.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Chemical- and hydrostatic-pressure-controlled metallization in NiS2−xSex\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2025-11-05 15:28:07\",\"doi\":\"10.21203/rs.3.rs-7784767/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0},{\"type\":\"decision\",\"content\":\"Revision requested\",\"date\":\"2026-01-17T15:13:01+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2026-01-16T04:35:15+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"327181720524641548940623123853609568349\",\"date\":\"2025-12-28T03:24:04+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2025-12-22T16:49:15+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"137724447297191491454017094116073014698\",\"date\":\"2025-11-29T06:54:25+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"261099943939263139217697208993354593719\",\"date\":\"2025-11-28T14:12:43+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewersInvited\",\"content\":\"\",\"date\":\"2025-10-27T03:14:12+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorInvited\",\"content\":\"\",\"date\":\"2025-10-10T08:08:02+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorAssigned\",\"content\":\"\",\"date\":\"2025-10-07T09:21:28+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"checksComplete\",\"content\":\"\",\"date\":\"2025-10-07T09:20:10+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"submitted\",\"content\":\"Scientific Reports\",\"date\":\"2025-10-05T12:41:18+00:00\",\"index\":\"\",\"fulltext\":\"\"}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"scientific-reports\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"scirep\",\"sideBox\":\"Learn more about [Scientific Reports](http://www.nature.com/srep/)\",\"snPcode\":\"\",\"submissionUrl\":\"\",\"title\":\"Scientific Reports\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"stoa\",\"reportingPortfolio\":\"Scientific Reports\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":true}}],\"origin\":\"\",\"ownerIdentity\":\"2d6be1fa-3c29-43cc-a313-e9e2cbc529f1\",\"owner\":[],\"postedDate\":\"November 5th, 2025\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"published-in-journal\",\"subjectAreas\":[{\"id\":57496277,\"name\":\"Physical sciences/Chemistry\"},{\"id\":57496278,\"name\":\"Physical sciences/Materials science\"},{\"id\":57496279,\"name\":\"Physical sciences/Physics\"}],\"tags\":[],\"updatedAt\":\"2026-03-16T16:05:08+00:00\",\"versionOfRecord\":{\"articleIdentity\":\"rs-7784767\",\"link\":\"https://doi.org/10.1038/s41598-026-42983-1\",\"journal\":{\"identity\":\"scientific-reports\",\"isVorOnly\":false,\"title\":\"Scientific Reports\"},\"publishedOn\":\"2026-03-12 15:59:37\",\"publishedOnDateReadable\":\"March 12th, 2026\"},\"versionCreatedAt\":\"2025-11-05 15:28:07\",\"video\":\"\",\"vorDoi\":\"10.1038/s41598-026-42983-1\",\"vorDoiUrl\":\"https://doi.org/10.1038/s41598-026-42983-1\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-7784767\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-7784767\",\"identity\":\"rs-7784767\",\"version\":[\"v1\"]},\"buildId\":\"8U1c8b4HqxoKbykW_rLl7\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}