Decoupling of structural and electronic phase transitions in VO$_2$

ORAL

Abstract

Using optical, TEM and ultrafast electron diffraction experiments we find that single crystal VO$_2$ microbeams gently placed on insulating substrates or metal grids exhibit different behaviors, with structural and metal-insulator transitions occuring at the same temperature for insulating substrates, while for metal substrates a {\it new monoclinic metal phase} lies between the insulating monoclinic phase and the metallic rutile phase. The structural and electronic phase transitions in these experiments are strongly first order and we discuss their origins in the context of current understanding of multi-orbital splitting, strong correlation effects and structural distortions that act cooperatively in this system.

*Research at Michigan State University is supported by Department of Energy under Grant No. DE-FG02-06ER46309. J.W. acknowledges support from the National Science Foundation under Grant No. ECCS-1101779

–

Authors

  • Zhensheng Tao

    • Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824, USA

  • Tzong-Ru T. Han

    • Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824, USA

  • Subhendra D. Mahanti

    • Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824, USA

  • Phillip M. Duxbury

    • Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824, USA

  • Fei Yuan

    • Physics and Astronomy Department, Michigan State University
    • Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824, USA

  • Chong-yu Ruan

    • Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824, USA
    • Physics and Astronomy Department, Michigan State University

  • Kevin Wang

    • Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA

  • Junqiao Wu

    • Department of Material Science and Engineering, University of California, Berkeley
    • Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA