Strain Effects on the Structural and Metal-Insulator Transition in Vanadium Oxides

ORAL

Abstract

The concomitance of the structural phase transition (SPT) and metal-insulator transition (MIT) in vanadium oxides (VO2 and V2O3) is currently under debate following suggestions that these transitions may occur at different temperatures. This has important implications for the driving mechanism of the transition. To shed light on this, we correlated the MIT and SPT of vanadium oxide thin films by means of temperature dependent X-ray diffractometry and infrared reflectivity, while using the film resistance as an internal indicator of the state of the system. We measured films of varying thicknesses, grown on different crystallographic orientations of the substrate to study how strain affects the structural and electronic transitions.

Interestingly, depending on substrate orientation and film thickness, we find asymmetry in the transition between cooling and heating, giving rise to large differences in resistance for the same high temperature phase fraction. We also find unexpected behavior of the monoclinic twinning across the transition for certain films. The concomitance of the MIT and SPT and the implications thereof will be discussed.

*This research is supported by UC MRPI 15-328528, and a DOD Vannevar Bush fellowship. J. del Valle and J. Trastoy thank Fundación Ramón Areces.

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Presenters

  • Yoav Kalcheim

    • Department of Physics and Center for Advanced Nanoscience, Univ of California - San Diego
    • Department of Physics and Center for Advance Nanoscience, University of California San Diego
    • Physics Department and Center for Advanced Nanoscience, University of California San Diego

Authors

  • Yoav Kalcheim

    • Department of Physics and Center for Advanced Nanoscience, Univ of California - San Diego
    • Department of Physics and Center for Advance Nanoscience, University of California San Diego
    • Physics Department and Center for Advanced Nanoscience, University of California San Diego

  • Nikita Butakov

    • Electrical and Computer Engineering Department, University of California Santa Barbara

  • Minhan Lee

    • Department of Physics and Center for Advanced Nanoscience, Univ of California - San Diego
    • Physics Department and Center for Advanced Nanoscience, University of California San Diego

  • Javier Del Valle Granda

    • Department of Physics, Univ of California - San Diego
    • Department of Physics and Center for Advanced Nanoscience, Univ of California - San Diego
    • Department of Physics and Center for Advance Nanoscience, University of California San Diego
    • Physics Department and Center for Advanced Nanoscience, University of California San Diego

  • Juan Trastoy

    • Department of Physics and Center for Advanced Nanoscience, Univ of California - San Diego
    • Physics Department and Center for Advanced Nanoscience, University of California San Diego

  • Jon Schuller

    • UC Santa Barbara
    • Electrical and Computer Engineering Department, University of California Santa Barbara

  • Ivan Schuller

    • Department of Physics, Univ of California - San Diego
    • University of California, San Diego
    • Department of Physics and Center for Advanced Nanoscience, Univ of California - San Diego
    • UC San Diego
    • Department of Physics and Center for Advance Nanoscience, University of California San Diego
    • Physics Department and Center for Advanced Nanoscience, University of California San Diego
    • Univ of California - San Diego
    • Physics, University of California, San Diego