Nonvolatile resistive switching behaviour and the mechanism in Nd:BiFeO₃/Nb:SrTiO₃ heterostructure

This paper reports the bipolar resistive switching (RS) effect of the Nd_0.05Bi_0.95FeO₃/Nb:SrTiO₃ heterostructure fabricated by pulsed laser deposition. This heterostructure shows a high RS ratio of over 600 at a read voltage of -0.3V after applying 5V/-8V pulse voltages. Moreover, the resistance states could be switched reversibly among multilevel resistance states by changing the magnitude of set or reset pulse voltages, which shows promise for multilevel nonvolatile memory application. The mechanism of the RS between high- and low-resistance states could be attributed to the carrier injection-trapped/detrapped process, which changes the height and thickness of the barrier at the Nd_0.05Bi _0.95FeO₃/Nb:SrTiO₃interface.