Metal-insulator transition and resistive switching in Y-doped CeO2 ceramics

Abstract

Y-doped ceria, Y_0.16Ce_0.84O_1.92, is an oxide ion conductor that shows n-type conductivity under a small applied voltage. With increasing voltage, resistive switching by 2–3 orders of magnitude occurs that is reversible with some hysteresis and is enhanced in atmospheres of reduced pO₂. The switching is a bulk effect, is not associated with Schottky barriers or with a crystallographic transition, occurs rapidly after a premonitory onset period depending on conditions and shows characteristics of a Mott transition. This is the third known example of low field-induced resistive switching in a bulk ceramic and represents an emergent phenomenon in materials that are taken outside their zone of thermodynamic stability.