Significant changes in the ferroelectric properties of BiFeO3 modified SrBi2Ta2O9

The solid solution of BiFeO3 (BF)-SrBi2Ta2O9 (SBT) prepared at a concentration of 1:1 ratio, shows significant changes in the structure and dielectric properties. The obtained compound although similar to a three-layered Aurivillius phase, is noticeably a Bi and oxygen deficient SBT phase. Due to this, the unit cell shows a subtle decrease in its volume and the dielectric properties show a decline. The layered perovskite structure sustains the strain associated with the loss of Bi and oxygen. SrBi3Ta2FeO12 has been synthesized by solid-state route and the single phase was confirmed by x-ray diffraction. The Curie temperature shows a marginal increase (an increase of 20degreesC) compared to that of SBT. Polarization versus electric measurements show a slim hysteresis loop with a P-max of 4.3 muC/cm(2). The electromechanical coupling coefficient "K-P" values are evaluated from the resonance and antiresonance measurements. (C) 2003 American Institute of Physics.