Thermopower analysis of the electronic structure around the metal-insulator transition in V1-x Wx O2

Abstract

The electronic structure across the metal-insulator (MI) transition of electron-doped V1-xWxO2 epitaxial films (x=0-0.06) grown on α-Al2O3 substrates was studied by means of thermopower (S) measurements. Significant increase of |S| values accompanied by MI transition was observed, and the transition temperatures of S (TS) decreased with x in a good linear relation with MI transition temperatures. |S| values of V1-xWxO2 films at T>TS were constant at low values of 23μVK-1 independently of x, which reflects a metallic electronic structure, whereas those at T