Interface Resistance Switching Characteristics of Metal/Nb-Doped SrTiO3 Junctions

Abstract

We report on the transport properties of junctions consisting of metal electrodes (M = Ti, Ni, and Pt) and (001)-oriented Nb-doped SrTiO3 (Nb:STO) single crystals. The junctions with M = Ti, which had a shallow work function, exhibited linear current-voltage (I-V ) characteristics without hysteresis. For M = Ni and Pt, with a large work function, the junctions showed rectifying I-V characteristics and notable hysteresis upon polarity reversal. The resistance change ratio for M = Ni (Pt) did (not) depend on the doping ratio of Nb:STO. This clearly suggests that the metal work function may not be sufficient to explain the resistance switching.