Sintering behavior and microwave dielectric properties of Li2O–B2O3–SiO2 doped MgTiO3–CaTiO3 ceramics

The influence of the addition of low-melting point Li2O–B2O3–SiO2 (LBS) on the sintering behavior and microwave dielectric properties of commercial 0.95MgTiO3–0.05CaTiO3 (95MCT) was systematically investigated by means of an X-ray diffractometer, a scanning electron microscope and a network analyzer. The results revealed that the addition of an appropriate amount of LBS enables the 95MCT composite ceramic to sinter in an obviously low sintering temperature, simultaneously leading to a more uniform and compact microstructure. Furthermore, favorable microwave dielectric properties of εr = 18.2, Qxf = 67,000 GHz (7.9 GHz), τf = −5.2 ppm/°C) were yielded in the 10 wt% LBS-doped 95MCT sample when sintered at 1025 °C for 4 h, indicating that LBS is an effective ternary firing agent when employed in 95MCT system. The relatively low sintering temperature together with acceptable microwave dielectric properties enable the composite ceramic to be a more potential alternative for the present patch antennas.