90 degree switching of polarization in [La.sup.3+]-doped Sr[Bi.sub.2][Ta.sub.2][O.sub.9] thin films

The polarization switching in [La.sup.3+]-doped Sr[Bi.sub.2][Ta.sub.2][O.sub.9] thin films is analyzed with the help of piezoresponse force microscopy and the effect of polarization switching on the fatigue behavior is discussed. The stress is created due to the 90 degree polarization switching in Sr[Bi.sub.1.4][La.sub.0.6][Ta.sub.2][O.sub.9] (SBLT) thin films, the internal stress increases with the repeated switching cycles and hence the polarization reorientation in SBLT is constrained.