Theoretical study of the resistance switching mechanism in rutile TiO2−x for ReRAM: The role of oxygen vacancies and hydrogen impurities

We study the resistance switching mechanism of rutile TiO<inf>2</inf> using ab initio calculations based on DFT. Ordering of the oxygen vacancies substantially increases the conductivity of TiO<inf>2</inf> by forming a conductive channel, i.e. “ON”-state. We find that the diffusion of either oxygen or hydrogen atoms into the conductive channel causes the rupture of the conductive filament resulting in the transition from “ON”-state to “OFF”-state.