Effects of B2O3 addition on sintering behavior and microwave dielectric properties of (Sr0.6Ca0.4)LaAlO4 ceramics

(Sr0.6Ca0.4)LaAlO4 ceramics were prepared by conventional solid-state reaction with 0.1-0.4 wt% of B2O3 as sintering aid. The effects of B2O3 addition on the sintering behavior, microstructure, and microwave dielectric properties of (Sr0.6Ca0.4)LaAlO4 ceramics were investigated. The densification temperature for (Sr0.6Ca0.4)LaAlO4 ceramics was as high as 1400 °C, while it could be obviously decreased with B2O3 addition, and the dense ceramics could be obtained around 1300 °C. The fine microstructures were achieved in the B2O3 doped samples sintered at the lower temperatures, and good microwave dielectric properties with a dielectric constant (ϵr) of 18.9, Q × f value of 63,000 GHz, and temperature coefficient of resonant frequency (τf) of −24.5 ppm/°C were obtained for 0.15 wt% B2O3 doped (Sr0.6Ca0.4)LaAlO4 ceramics.