VO2 nanosheets: controlling the THz properties through strain engineering

TL;DR

This paper explores how strain engineering in VO2 nanosheets affects their far-infrared and THz properties, revealing anisotropic behavior and Mott-Hubbard characteristics along the rutile c-axis.

Contribution

It demonstrates the control of THz properties in VO2 nanosheets through epitaxial strain, highlighting anisotropic phase transition and electronic behavior.

Findings

Large uniaxial strain induces uniform cracks along the c-axis.

Significant anisotropy in metal-insulator transition temperature and conductivity.

Evidence of Mott-Hubbard like behavior along the rutile c-axis.

Abstract

We investigate far-infrared properties of strain engineered vanadium dioxide nanosheets through epitaxial growth on a (100)R TiO2 substrate. The nanosheets exhibit large uniaxial strain leading to highly uniform and oriented cracks along the rutile c-axis. Dramatic anisotropy arises for both the metal-insulator transition temperature, which is different from the structural transition temperature along the cR axis, and the metallic state conductivity. Detailed analysis reveals a Mott-Hubbard like behavior along the rutile cR axis.