Hysteretic current–voltage characteristics and resistance switching at an epitaxial oxide Schottky junction SrRuO3∕SrTi0.99Nb0.01O3

Transport properties have been studied for a perovskite heterojunction consisting of $\mathrm{Sr}\mathrm{Ru}{\mathrm{O}}_3$ (SRO) film epitaxially grown on $\mathrm{Sr}{\mathrm{Ti}}_{0.99}{\mathrm{Nb}}_{0.01}{\mathrm{O}}_3$ (Nb:STO) substrate. The SRO/Nb:STO interface exhibits rectifying current–voltage $(I–V)$ characteristics agreeing with those of a Schottky junction composed of a deep work-function metal (SRO) and an $n$ -type semiconductor (Nb:STO). A hysteresis appears in the $I–V$ characteristics, where high resistance and low resistance states are induced by reverse and forward bias stresses, respectively. The resistance switching is also triggered by applying short voltage pulses of $1\mu \mathrm{s}–10\mathrm{ms}$ duration.