On the resistive switching mechanisms of

We use convincing experimental evidences to demonstrate that the nonpolar resistive switching phenomenon observed in Cu/ZrO2:Cu/Pt memory devices conforms to a filament formation and annihilation mechanism. Temperature-dependent switching characteristics show that a metallic filamentary channel is responsible for the low resistance state (ON state). Further analysis reveals that the physical origin of this metallic filament is the nanoscale Cu conductive bridge. On this basis, we propose that the set process (switching from OFF state to ON state) and the reset process (switching from ON to OFF state) stem from the electrochemical reactions in the filament, in which a thermal effect is greatly involved.