Effect of sintering temperature on dielectric, piezoelectric and ferroelectric properties of BZT-BCT 50/50 ceramics

摘要

Lead free 0.5[Ba(Zr_(0.2)Ti_(0.8))O_3]-0.5[(Ba_(0.7)Ca_(0.3))TiO_3]/[BZT-BCT 50/50] ceramics were synthesized by conventional solid state reaction route. The effect of sintering temperature on structural and electrical properties of BZT-BCT 50/50 ceramics were studied in detail. The coexistence of tetragonal-monoclinic structures confirmed the MPB nature of BZT-BCT 50/50 ceramics. Grain size, density and dielectric constant at room temperature of BZT-BCT 50/50 ceramics increased with the increase of sintering temperature. Increase of T_c with sintering temperature confirmed the effect of relieving of internal stress by grain-boundary sliding. Increase of diffuse phase transition indicated that with the increase in sintering temperature the competition between Ti and Zr ions increased to occupy the same crystallographic site B, which leads to increase in composition fluctuations of different polar micro-regions. A max. strain as high as ～0.36% has been obtained in BZT-BCT 50/50 ceramic samples sintered at 1300 °C.