Different fatigue behaviors of SrBi2Ta2O9 and Bi3TiTaO9 films:: Role of perovskite layers

To investigate the role of the perovskite layers on fatigue behaviors, SrBi2Ta2O9(SBT) and Bi3TiTaO9 (BTT) films were prepared by pulsed laser deposition using 15% Bi-excess bulk targets. The SBT and the BTT films grown at the similar deposition conditions showed similar growth behaviors, electrical properties, and retention characteristics. However, these films showed very different fatigue behaviors. The difference should come from the oxygen stability in the perovskite layer. Our work demonstrates that oxygen stability of the perovskite layers, as well as the self-regulating adjustment of the Bi2O2 layers, should be considered in the search for new candidate materials for nonvolatile ferroelectric memory devices. (C) 1999 American Institute of Physics. [S0003-6951(99)02243-3].