Structural studies of BiFeO3 modified BMZ-PT ceramics

Bismuth perovskites have been attracting attention as a family of piezoelectric ceramics in place of the widely used Pb (Zr,Ti)O-3 (PZT) system. The advantages of bismuth perovskites over PZT are environmentally more-friendly materials, a higher mechanical strength and Curie temperature. Most recently BiMgZrO3-PbTiO3 has been reported to be high temperature morphotropic phase boundary (MPB) piezoelectric with appreciably good ferroelectric and piezoelectric properties. Bismuth containing crystalline solutions [(BiMgZrO3)(1-y)-(BiFeO3)(y)](x)-(PbTiO3)(1-x), (BMZ-BF-PT) have been synthesized by high temperature solid-state reaction technique. The crystalline symmetry varied with the composition, indicating good solid-state solubility of BMZ and BF with PT. X-ray diffraction (XRD) reveals that BMZ-BF-PT has a single-phase perovskite structure. The Morphotropic Phase Boundary (MPB) of BMZ-PT system lies in the region x=0.55 to x=0.6 which is supported by the transformation from tetragonal to rhombohedral phase. The SEM photographs reveal the uniform distribution of grains in the matrix. Variation of dielectric parameters with frequency (at room temperature) exhibit typical dielectric behavior for all compositions. (C) 2006 Elsevier B.V. All rights reserved.