Enhanced Grain Orientation in Pb(Zr,Ti)O3 Powder-Modified SrBi2Ta2O9 Ferroelectric Ceramics

Abstract

Abstract Pb(Zr,Ti)O3 (PZT) powder modified SrBi2Ta2O9 (SBT) ceramics, hereafter called SBT-PZT, were prepared by the solid phase synthesis method. With the aid of atomic force microscopy and x-ray diffractometry, the SBT-PZT ceramics were found to exhibit an enhanced c-axis orientation compared with SBT ceramics. Ferroelectric and dielectric properties of SBT-PZT ceramics were revealed to be anisotropic by relevant measurements. Because of differences in heteropolar valence and ionic radius between SBT and PZT, the PZT may be introduced into SBT as a heterogeneous system and embedded in the SBT grain boundaries. The large differences in crystal structures between SBT and PZT were proposed to be responsible for the SBT-PZT grain orientation mechanism. Obviously, the grain orientation resulted in electrical anisotropies of SBT-PZT ceramic. The internal stress, which was induced by heterogeneous system doping, was considered to affect the polarization reversal of SBT-PZT ceramics.