Memristive Behavior in Thin Anodic Titania

A common material in creating memristors is titanium dioxide (TiO2), grown by atomic layer deposition, sputtering, or sol-gel process. In this letter, we study the memristive behavior in thin TiO2 films fabricated by brief electrochemical anodization of titanium. The effects of different anodization times and annealing are explored. We discover that inherent oxygen-vacancies at the bottom Ti/TiO2 interface naturally lead to memristive switching in nonannealed films. Annealing induces extra oxygen vacancies near the top metal/oxide interface, which leads to symmetric and ohmic current-voltage characteristics with a collapse of memristive switching. No clear dependence on anodization time was observed for times between 1 s and 1 min.