Abstract

The insulator–metal transition remains among the most studied phenomena in correlated electron physics. However, the spontaneous formation of spatial patterns amidst insulator–metal phase coexistence remains poorly explored on the meso- and nanoscales. Here we present real-space evolution of the insulator–metal transition in a V2O3 thin film imaged at high spatial resolution by cryogenic near-field infrared microscopy. We resolve spontaneously nanotextured coexistence of metal and correlated Mott insulator phases near the insulator–metal transition (160–180 K) associated with percolation and an underlying structural phase transition. Augmented with macroscopic temperature-resolved X-ray diffraction measurements of the same film, a quantitative analysis of nano-infrared images acquired across the transition suggests decoupling of electronic and structural transformations. Persistent low-temperature metallicity is accompanied by unconventional critical behaviour, implicating the long-range Coulomb interaction as a driving force through the film’s first-order insulator–metal transition.

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Acknowledgements

A.S.M., E.v.H., M.G., L.A., P.K., A.M., M.K.L. and D.N.B. were supported by DOE-DE-SC0012375 and DOE-DE-SC0012592. J.G.R., S.W., T.S., S.G. and I.K.S. were supported by AFOSR Grant No. FA9550-12-1-0381. A.S.M. acknowledges support from a US Department of Energy Office of Science Graduate Fellowship (SCGF). Development of methods for cryogenic nano-infrared imaging is supported by ARO-w911NF-13-1-0210 and ONR-N00014-15-1-2671. D.N.B. is the Gordon and Betty Moore Foundation’s Investigator in Quantum Materials award under the EPiQS Initiative through Grant GBMF4533. E.v.H. acknowledges the support of the US National Science Foundation I2CAM International Materials Institute Award, Grant DMR-0844115.

Author information

Author notes

    • J. G. Ramirez
    • , T. Saerbeck
    •  & M. K. Liu

    Present addresses: Universidad de los Andes, Bogotá 111711, Colombia (J.G.R.); Institut Laue-Langevin, 71 avenue des Martyrs, 38000 Grenoble, France (T.S.); Stony Brook University, Stony Brook, New York 11794, USA (M.K.L.).

Affiliations

  1. University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA

    • A. S. McLeod
    • , E. van Heumen
    • , J. G. Ramirez
    • , S. Wang
    • , T. Saerbeck
    • , S. Guenon
    • , M. Goldflam
    • , L. Anderegg
    • , P. Kelly
    • , A. Mueller
    • , M. K. Liu
    • , Ivan K. Schuller
    •  & D. N. Basov
  2. University of Amsterdam, Sciencepark 904, 1098 XH Amsterdam, Netherlands

    • E. van Heumen
  3. Department of Physics, Columbia University, 538 West 120th Street New York, New York 10027, USA

    • D. N. Basov

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Contributions

Experiments were conceived jointly by all authors. S.W. and J.G.R. grew the V2O3 film. A.S.M. and E.v.H. performed nano-IR measurements on the film, while J.G.R. and T.S. performed ex situ X-ray diffraction and resistance measurements. A.S.M., E.v.H., M.G., L.A. and P.K. developed the nano-IR instrumentation. All authors prepared the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to A. S. McLeod.

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https://doi.org/10.1038/nphys3882