Stress-induced domain dynamics and phase transitions in epitaxially grown VO₂ nanowires

Nanotechnology. 2012 May 25;23(20):205707. doi: 10.1088/0957-4484/23/20/205707.

Abstract

We demonstrate that surface stresses in epitaxially grown VO₂ nanowires (NWs) have a strong effect on the appearance and stability of intermediate insulating M₂ phases, as well as the spatial distribution of insulating and metallic domains during structural phase transitions. During the transition from an insulating M1 phase to a metallic R phase, the coexistence of insulating M₁ and M₂ phases with the absence of a metallic R phase was observed at atmospheric pressure. In addition, we show that, for a VO₂ NW without the presence of an epitaxial interface, surface stresses dominantly lead to spatially inhomogeneous phase transitions between insulating and metallic phases. In contrast, for a VO₂ NW with the presence of an epitaxial interface, the strong epitaxial interface interaction leads to additional stresses resulting in uniformly alternating insulating and metallic domains along the NW length.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Computer Simulation
  • Electric Conductivity
  • Materials Testing
  • Models, Chemical*
  • Models, Molecular*
  • Molecular Conformation
  • Nanostructures / chemistry*
  • Nanostructures / ultrastructure*
  • Particle Size
  • Phase Transition
  • Stress, Mechanical
  • Surface Properties
  • Vanadium Compounds / chemistry*

Substances

  • Vanadium Compounds
  • vanadium pentoxide