Structural and ferroelectric characterization of BMZ–BF–PT ceramics

Bismuth containing crystalline solid solutions of [(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–PT and BMZ–BF–PT have a single-phase perovskite structure. The MPB of BMZ–PT lies in the region x = 0.55 to x = 0.6, which is supported by the transformation from rhombohedral to tetragonal phase. The SEM photographs exhibit the uniform distribution of grains in the matrix. Polarization–electric field hysteresis studies were carried out at Room Temperature for all the compositions up to an applied electric field of 3.5 kV/mm. It was found that with the increase of BiFeO₃ content in the composition the remnant polarization decreases and the ferroelectric loops get constricted. Variation of dielectric constant with temperature shows that there is an increase in Transition temperature (T _C) with the increase in applied frequency indicating a relaxor characteristic of the compound. Our results show that BMZ–BF–PT is a good low-lead (Pb) high-temperature ferroelectric ceramic.