High-performance ferroelectric nonvolatile memory based on Gd-and Ni-codoped BiFeO(3) films

BiFeO(3) (BFO), Bi(0.92)Gd(0.08)FeO(3) (BGFO) and Bi(0.92)Gd(0.08)Fe(0.95)Ni(0.05)O(3) (BGFNO) films are epitaxially grown on 0.7 wt% Nb-SrTiO(3) (NSTO) substrates. The strong ferroelectric property in BGFNO film is confirmed by piezoresponse force microscopy (PFM) and polarization versus voltage (P–V) measurement. It is also found that the Au/BGFNO/NSTO devices possess a ferroelectric resistance switching (RS) effect. Gd- and Ni-codoped BiFeO(3) is found to strongly enhance the resistance on/off ratio. A resistance on/off ratio as large as 3 × 10(6) is achieved with an applied pulse voltage of −8 V and +4 V. In addition, the devices exhibit excellent retention and anti-fatigue characteristics. The memristor behavior of Au/BGFNO/NSTO is attributed to the switching of polarization states, which modulate the width and height of the barrier at the BGFNO/NSTO interface. The excellent resistive switching properties in Au/BGFNO/NSTO devices indicate the promising application in nonvolatile memory.