Enhanced dielectric and piezoelectric properties of BZT-BCT system near MPB

Lead free ferroelectric ceramics of x[Ba(Zr0.2Ti0.8)O3]-(1−x)[(Ba0.7Ca0.3)TiO3]/(BZT-BCT) system for x=(0.48, 0.50, 0.52), were synthesized by conventional solid state reaction route at different sintering temperatures ranging from 1300 to 1400 °C. The dielectric, ferroelectric and piezoelectric properties of the (BZT-BCT) system, sintered at different temperatures, were studied in detail. X-ray diffraction (XRD) study revealed the single perovskite phase at room temperature (RT) for all the MPB compositions. Scanning electron microscopy (SEM) study of the sintered (BZT-BCT) ceramics revealed dense and homogeneous packing of grains. A morphotropic phase boundary (MPB), consisting of monoclinic and tetragonal structures, was identified for x=0.50. Enhanced dielectric constant (εr) ~3888 at room tempearture, and the maximum piezoelectric constant (d33)=281 pC/N were observed in the MPB composition, sintered at 1400 °C, for x=0.50. Polarization vs. electric field (P-E) hysteresis loop study of the (BZT-BCT) samples showed the increase in polarization with the increase of sintering temperature.