Role of growth conditions and Bi-content on the properties of SrBi2Ta2O9 thin films

Ex-situ and in-situ crystallised films of SrBi2Ta2O9 (SBT) were grown using pulsed laser ablation. Different growth parameters were used for ablation. Both low temperature grown films, followed by annealing and high temperature grown ones were used for comparison. It was found that in-situ crystallised films showed better electrical properties over the annealed films, vis-ci-vis the hysteresis loops and dielectric constants. It was also observed that the Bi concentration (which was estimated by EDS analysis) had a marked influence on the ferroelectric properties. With stoichiometric or excess Bi content, growth of in-situ crystallised films resulted in the observation of square hysteresis loops with a P-r value of 10 mu C/cm(2) and a coercive field of 24 kV/cm, which appears very attractive for NVRAM applications. (C) 1998 Elsevier Science Ltd. All rights reserved.