Characterization of electronic structure around metal-insulator transition in V1-xWxO2 thin films by thermopower measurement

Abstract

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 good linear relation with MI transition temperatures. |S| values of V1-xWxO2 films at T > TS were constant at low values of 23 μVK-1 independently of x, which reflects a metallic electronic structure, whereas, those at T