Two-Step Sintering, Microstructure and Electrical Properties of (Ba, Ca)(Ti, Zr)O_3 Lead-Free Ceramics

摘要

In this work, the (Ba_(1-x)Ca_x)(Ti_(1-y)Zr_y)O_3 lead-free ceramics were prepared by the two-step sintering method, and effects of Ca and Zr contents on phase structure, densification, microstructure, and electrical properties were investigated. It was found that all samples showed orthorhombic phase. The highest density of 5.84 ± 0.01 g/cm~3 was achieved in x = 0.05, y = 0.05 sample. The average grain size, phase transition temperature, dielectric and piezoelectric properties significantly decreased by introducing of the Ca/Zr content. The ceramics with a small amount of Ca and Zr maintain good piezoelectric properties, and a lower dielectric loss. The composition with x = 0.05, y = 0.025 demonstrated optimum electrical properties of d_(33) ～211 pC/N, T_C ～ 119°C, ε_r ～ 1788, and tanδ ～ 0.04.