Stable bipolar resistance switching behaviour induced by a soft breakdown process at the Al/La0.7Ca0.3MnO3 interface

The current-voltage characteristics, carrier transport processes and electric pulse induced resistance switching behaviour have been investigated in Al/La0.7Ca0.3MnO3 (LCMO)/Pt sandwich structures. A stable resistance switching effect was obtained when a soft breakdown process occurred during negative voltage sweeping. Moreover, the trigger condition of the high resistance state is completely different from that of the low resistance state. Based on the investigation on the carrier transport processes of different resistance states, it is suggested that the resistance switching effect is closely related to the resistance change of the AlOx layer formed at the Al/LCMO interface. The local oxidation/reduction of the AlOx layer associated with the rupture/formation of conductive filaments is proposed to explain the resistance switching effect. A simple method to control the oxidation/reduction of the AlOx layer has been devised to improve the resistance switching properties by adjusting the thickness of the Al electrode.