Crossing Thermal Lubricity and Electronic Effects in Friction: Vanadium Dioxide under the Metal-Insulator Transition

Abstract

The remarkable turnover of friction on a vanadium dioxide (VO2) surface driven by the metal-insulator transition is revealed using temperature-variable atomic force microscopy in ultrahigh vacuum. Phononic and electronic contributions are known as two major components in mediating friction energy dissipation. Here, a VO2 thin film is prepared on a silicon wafer with preferential orientations of (100) and (120) in the monoclinic phase using pulsed laser deposition. Corresponding friction and conductivity images show that friction decreases below the critical temperature, above which two trends are seen as the temperature increases: less friction on the insulating domains and higher friction on the metallic domains. This distinct temperature dependence of friction is attributed to the combined effects of thermal lubricity and electronic contributions. This study indicates the promising potential for vanadium oxide to tune friction in the electric regime as well as with temperature.