Nonvolatile bipolar resistive switching in Au/BiFeO3/Pt
  Nonvolatile bipolar resistive switching has been observed in an Au/BiFeO3/Pt structure, where a Schottky contact and a quasi-Ohmic contact were formed at the Au/BiFeO3 and BiFeO3/Pt interface, respectively. By changing the polarity of the external voltage, the Au/BiFeO3/Pt is switched between two stable resistance states without an electroforming process. The resistance ratio is larger than two orders of magnitude. The resistive switching is understood by the electric field - induced carriers trapping and detrapping, which changes the depletion layer thickness at the Au/BiFeO3 interface. 
Yao Shuai, Shengqiang Zhou, Danilo B\"urger, Manfred Helm, Heidemarie   Schmidt
cond-mat.mtrl-sci cond-mat.mes-hall