Dielectric and Piezoelectric Properties of 0.36BiScO3 - 0.64PbTiO3 Ceramic Doped with Calcium Fluoride

Abstract

BiScO3-xPbTiO3 (BS-PT) of perovskite type structure (with x~0.64) were prepared by solid state ceramic process with addition of calcium fluoride (CaF2) in different molar ratios (0.5, 1.0 and 4.0 mol%). The doped compositions were found to have different symmetry compared with parent material. The 0.5 mol% doped sample was found to possess enhanced rhombohedral phase as compared to other compositions while he Curie temperature (Tc) was not affected appreciably. Small dielectric peaks were observed, indicating phase transition, at temperature lower than Tc in all the samples except 4.0% doped composition. At room temperature doping reduced the loss factor. d33 and Pr reduced rapidly with doping. The characteristics of BS-PT ferroelectric ceramics became harder with the addition of CaF2.