Separating electric field and thermal effects across the metal-insulator transition in vanadium oxide nanobeams

Abstract

We present results from an experimental study of the equilibrium and non-equilibrium transport properties of vanadium oxide nanobeams near the metal-insulator transition (MIT). Application of a large electric field in the insulating phase across the nanobeams produces an abrupt MIT, and the individual roles of thermal and non-thermal effects in driving the transition are studied. Transport measurements at temperatures (T) far below the critical temperature (Tc) of MIT, in nanoscale vanadium oxide devices, show that both T and electric field play distinctly separate, but critical roles in inducing the MIT. Specifically, at T≪Tc, electric field dominates the MIT through an avalanche-type process, whereas thermal effects become progressively critical as T approaches Tc.