Improved sintering characteristics and microwave dielectric properties of CaLa4Ti4O15 ceramics with BiVO4 addition

Effects of BiVO4 addition on the sintering behavior, crystal structure, microstructure and microwave dielectric properties of CaLa4Ti4O15 ceramics were investigated. When BiVO4 addition is below 3 %, the sintering temperature of CaLa4Ti4O15 ceramics is reduced from 1,550 °C to about 1,400 °C. And only phase CaLa4Ti4O15 is observed in the CaLa4Ti4O15 ceramics. However, the secondary phase CaLa4Ti5O17 appears when BiVO4 addition reached 3 %. It is important that a small amount of BiVO4 addition can not only lower the sintering temperature but also improve the microwave dielectric properties of CaLa4Ti4O15 ceramics. The CaLa4Ti4O15 ceramics with 1.0 % BiVO4 addition, which is sintered at 1,425 °C, exhibits excellent microwave dielectric properties of e = 44.3, Qf = 51,377 GHz, τ f = −9.0 ppm/°C. The variation of microwave dielectric properties had been also discussed with the structure evolution.