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Robust metal-insulator transition despite surface dead-layer growth in sub-10-nm Cr-doped V2O3 nanocrystals

Yoichi Ishiwata1,*, Ichidai Harada1, Masaki Imamura2, Kazutoshi Takahashi2, Hirofumi Ishii3, Masato Yoshimura3, Nozomu Hiraoka3, Yuji Inagaki4, Kenta Akashi5 et al.

Tatsuya Kawae5, Tetsuya Kida6, and Masashi Nantoh7,8

  • *Contact author: ishiwata@cc.saga-u.ac.jp
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Phys. Rev. Research 8, 033339 – Published 18 September, 2026

DOI: https://doi.org/10.1103/9g6w-r9sc

Abstract

We investigated the size dependence of the metal-insulator transition (MIT) in Cr-doped V2O3 nanocrystals by photoemission spectroscopy using complementary probing depths, together with magnetic susceptibility measurements. Photoemission spectra show that MIT signatures persist down to an average particle size of 5.6 nm, and magnetic susceptibility measurements exhibit a nearly size-invariant transition onset. The contrast between surface-sensitive and deeper-probing photoemission spectra reveals that the transition survives in the nanocrystal interior. At the same time, the spectra indicate a systematic suppression of coherent quasiparticle weight with decreasing size, pointing to the growth of an insulating surface dead layer. These results demonstrate that nanoscaling does not intrinsically eliminate the MIT itself, but progressively enhances the influence of surface-driven insulating behavior, thereby providing insight into the practical limits of miniaturizing Mott-based devices.

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References (32)

  1. S. Paschen and Q. Si, Quantum phases driven by strong correlations, Nat. Rev. Phys. 3, 9 (2021).
  2. W. Li, X. Qian, and J. Li, Phase transitions in 2D materials, Nat. Rev. Mater. 6, 829 (2021).
  3. X. Y. Lang, W. T. Zheng, and Q. Jiang, Size and interface effects on ferromagnetic and antiferromagnetic transition temperatures, Phys. Rev. B 73, 224444 (2006).
  4. C. Q. Sun, B. K. Tay, X. T. Zeng, S. Li, T. P. Chen, Ji Zhou, H. L. Bai, and E. Y. Jiang, Bond-order-bond-length-bond-strength (bond-OLS) correlation mechanism for the shape-and-size dependence of a nanosolid, J. Phys.: Condens. Matter 14, 7781 (2002).
  5. N. F. Mott, Metal-Insulator Transition, 2nd ed. (Taylor & Francis, London, 1990).
  6. N. Tsuda, K. Nasu, A. Fujimori, and K. Shiratori, Electronic Conduction in Oxides (Springer, Berlin, 2000).
  7. M. Imada, A. Fujimori, and Y. Tokura, Metal-insulator transitions, Rev. Mod. Phys. 70, 1039 (1998).
  8. H. Yokoyama, T. Miyagawa, and M. Ogata, Effect of doublon-holon binding on Mott transition-variational Monte Carlo study of two-dimensional Bose Hubbard models, J. Phys. Soc. Jpn. 80, 084607 (2011).
  9. G. Borghi, M. Fabrizio, and E. Tosatti, Surface dead layer for quasiparticles near a Mott transition, Phys. Rev. Lett. 102, 066806 (2009).
  10. Y. Ishiwata, T. Shiraishi, N. Ito, S. Suehiro, T. Kida, H. Ishii, Y. Tezuka, Y. Inagaki, T. Kawae, H. Oosato, E. Watanabe, D. Tsuya, M. Nantoh, and K. Ishibashi, Metal-insulator transition sustained by Cr-doping in V2O3 nanocrystals, Appl. Phys. Lett. 100, 043103 (2012).
  11. Y. Ishiwata, E. Takahashi, K. Akashi, M. Imamura, J. Azuma, K. Takahashi, M. Kamada, H. Ishii, Y.-F. Liao, Y. Tezuka, Y. Inagaki, T. Kawae, D. Nishio-Hamane, M. Nantoh, K. Ishibashi, and T. Kida, Impurity-induced first-order phase transitions in highly crystalline V2O3 nanocrystals, Adv. Mater. Interfaces 2, 1500132 (2015).
  12. Y. Ishiwata, T. Maruyama, S. Otsuru, T. Tsukahara, H. Ishii, Y.-F. Liao, K.-D. Tsuei, M. Imamura, K. Takahashi, Y. Inagaki, T. Kawae, T. Kida, S. Suehiro, M. Nantoh, and K. Ishibashi, Corundum insulating phases in highly Ti-doped nanocrystals, Phys. Rev. B 101, 035415 (2020).
  13. F. Rodolakis, B. Mansart, E. Papalazarou, S. Gorovikov, P. Vilmercati, L. Petaccia, A. Goldoni, J. P. Rueff, S. Lupi, P. Metcalf, and M. Marsi, Quasiparticles at the Mott transition in V2O3: Wave vector dependence and surface attenuation, Phys. Rev. Lett. 102, 066805 (2009).
  14. Y. Zhou and S. Ramanathan, Mott memory and neuromorphic devices, Proc. IEEE 103, 1289 (2015).
  15. Y. Wang, K.-M. Kang, M. Kim, H.-S. Lee, R. Waser, D. Wouters, R. Dittmann, J. J. Yang, and H.-H. Park, Mott-transition-based RRAM, Mater. Today 28, 63 (2019).
  16. Y. Ran, Y. Pei, Z. Zhou, H. Wang, Y. Sun, Z. Wang, M. Hao, J. Zhao, J. Chen, and X. Yan, A review of Mott insulator in memristors: The materials, characteristics, applications for future computing systems and neuromorphic computing, Nano Res. 16, 1165 (2023).
  17. T. Tsukahara, S. An, S. Otsuru, Y. Tezuka, K. Akashi, Y. Inagaki, T. Kawae, S. Nozawa, J. Adachi, H. Ishii, Y.-F. Liao, T. Kida, S. Suehiro, M. Nantoh, K. Ishibashi, and Y. Ishiwata, Correlation between ferromagnetism and dopant 3d metal-oxygen hybridized state lying at the bottom of conduction band in ZnO-based diluted magnetic semiconductor system, J. Appl. Phys. 130, 243904 (2021).
  18. Y. Ishiwata, G. Kawahara, K. Akase, T. Tominaga, H. Miyazaki, H. Ishii, A. Matsuo, K. Kindo, Y. Inagaki, K. Akashi, T. Kawae, T. Kida, S. Suehiro, M. Nantoh, and K. Ishibashi, Invariable simultaneous emergence of antiferromagnetic order and tetragonal deformation in CoO nanocrystals, J. Phys. Soc. Jpn. 93, 044603 (2024).
  19. F. Izumi and K. Momma, Three-dimensional visualization in powder diffraction, Solid State Phenom. 130, 15 (2007).
  20. S. Tanuma, C. J. Powell, and D. R. Penn, Calculations of electron inelastic mean free paths. V. Data for 14 organic compounds over the 50–2000 eV range, Surf. Interface Anal. 21, 165 (1994).
  21. H. Shinotsuka, S. Tanuma, C. J. Powell, and D. R. Penn, Calculations of electron inelastic mean free paths. X. Data for 41 elemental solids over the 50 eV to 200 keV range with the relativistic full Penn algorithm, Surf. Interface Anal. 47, 871 (2015).
  22. M. B. Trzhaskovskaya, V. I. Nefedov, and V. G. Yarzhemsky, Photoelectron angular distribution parameters for elements Z=1 to Z=54 in the photoelectron energy range 100–5000 eV, At. Data Nucl. Data Tables 77, 97 (2001).
  23. M. B. Trzhaskovskaya, V. K. Nikulin, I. Nefedov, and V. G. Yarzhemsky, Non-dipole second order parameters of the photoelectron angular distribution for elements Z=1–100 in the photoelectron energy range 1–10 keV, At. Data Nucl. Data Tables 92, 245 (2006).
  24. E. Papalazarou, M. Gatti, M. Marsi, V. Brouet, F. Iori, L. Reining, E. Annese, I. Vobornik, F. Offi, A. Fondacaro, S. Huotari, P. Lacovig, O. Tjernberg, N. B. Brookes, M. Sacchi, P. Metcalf, and G. Panaccione, Valence-band electronic structure of V2O3: Identification of V and O bands, Phys. Rev. B 80, 155115 (2009).
  25. S. Suehiro, K. Horita, K. Kumamoto, M. Yuasa, T. Tanaka, K. Fujita, K. Shimanoe, and T. Kida, Solution-processed Cu2ZnSnS4 nanocrystal solar cells: Efficient stripping of surface insulating layers using alkylating agents, J. Phys. Chem. C 118, 804 (2014).
  26. R. Hiraki, K. Akashi, S. Otsuru, M. Kakihara, H. Ishii, M. Yoshimura, M. Imamura, K. Takahashi, Y. Inagaki, T. Kawae, A. Matsuo, K. Kindo, T. Kida, M. Nantoh, and Y. Ishiwata, Near-surface electronic correlation and magnetization suppression in Ni nanocrystals, Phys. Rev. B 113, 144406 (2026).
  27. K. Binder, Theory of first-order phase transitions, Rep. Prog. Phys. 50, 783 (1987).
  28. K. Appavoo, D. Y. Lei, Y. Sonnefraud, B. Wang, S. T. Pantelides, S. A. Maier, and R. F. Haglund, Role of defects in the phase transition of VO2 nanoparticles probed by plasmon resonance spectroscopy, Nano Lett. 12, 780 (2012).
  29. C. C. Chen, A. B. Herhold, C. S. Johnson, and A. P. Alivisatos, Size dependence of structural metastability in semiconductor nanocrystals, Science 276, 398 (1997).
  30. S.-K. Mo, H.-D. Kim, J. D. Denlinger, J. W. Allen, J.-H. Park, A. Sekiyama, A. Yamasaki, S. Suga, Y. Saitoh, T. Muro, and P. Metcalf, Photoemission study of (V1−xMx)2O3(M=Cr,Ti), Phys. Rev. B 74, 165101 (2006).
  31. G. Panaccione, M. Altarelli, A. Fondacaro, A. Georges, S. Huotari, P. Lacovig, A. Lichtenstein, P. Metcalf, G. Monaco, F. Offi, L. Paolasini, A. Poteryaev, O. Tjernberg, and M. Sacchi, Coherent peaks and minimal probing depth in photoemission spectroscopy of Mott-Hubbard systems, Phys. Rev. Lett. 97, 116401 (2006).
  32. A. Hariki, T. Uozumi, and J. Kuneš, LDA + DMFT approach to core-level spectroscopy: Application to 3d transition metal compounds, Phys. Rev. B 96, 045111 (2017).

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Phys. Rev. Research 8, 033339– Published 18 September, 2026
  • Received 30 April 2026
  • Accepted 1 September 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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