Anisotropic structure deformation in the VO2 metal-insulator transition.
X-ray absorption fine structure data of tungsten (VI)-doped vanadium dioxide in the insulating phase, and during the metal-insulator transition, are presented for the first time. Tungsten L(III)- and vanadium K-edge data suggest that significant expansion in the [110] and [110] directions occurs across the phase transition from low to high temperature. This distortion breaks the bonds between Peierls-paired vanadium ions, opening a band gap, and reveals the nature of the mechanism by which tungsten doping lowers the transition temperature and enthalpy.
CSIRO Materials Science and Engineering, Private Bag 33, Clayton South, 3169, Victoria, Australia.
Jamie M
JM
Booth
Philip S
PS
Casey