Electrically induced insulator to metal transition in epitaxial SmNiO3 thin films

Abstract

We report on the electrically induced insulator to metal transition (IMT) in SmNiO3 thin films grown on (001) LaAlO3 by pulsed laser deposition. The behavior of the resistivity as a function of temperature suggests that the primary transport mechanism in the SmNiO3 insulating state is dominated by Efros-Shklovskii variable range hopping (ES-VRH). Additionally, the magnetic transition in the insulating state of SmNiO3 modifies the characteristics of the ES-VRH transport. Systematic DC and pulsed current-voltage measurements indicate that current-induced joule heating is the fundamental mechanism driving the electrically induced IMT in SmNiO3. These transport properties are explained in context of the IMT in SmNiO3 being related to the strong electron-lattice coupling.