Bipolar resistive switching in polycrystalline TiO2 films

Abstract

Bipolar resistive switching was found in thin polycrystalline TiO2 films formed by the thermal oxidation of sputtered Ti films. With a Ag top electrode, TiO2 film, and Pt bottom electrode, bistable resistive switching with a low operating voltage and a good uniformity was observed repeatedly without an initial electrical “forming” process. This switching phenomenon might be described as the formation and rupture of a filamentary conductive path consisting of a chain of Ag atoms. The temperature dependence of the switching voltage is discussed in terms of interstitial ionic diffusion of Ag in the TiO2 matrix.