Sintering Behavior and Microwave Dielectric Properties of Li_2O-B_2O_3-SiO_2 Doped 0.67CaTiO_3-0.33LaAlO_3 Ceramics

摘要

A low temperature sintering method was used to avoid the relatively high sintering temperatures typically required to prepare 0.67CaTiO_3-0.33LaAlO_3 (CTLA) ceramics. 0.67CaTiO_3-0.33LaAlO3 ceramics doped with Li_2O-B_2O_3-SiO_2 (LBS) were prepared by a conventional two-step solid-state reaction process. The sintering behavior, crystal structure, surface morphology, and microwave dielectric proprieties of the prepared ceramics were studied. As the small amount of LBS content increased, the small amount of liquid phase formed in an amorphous state around the surface of the grain boundaries. With the increase the content of LBS glass, the quality factor (Q×f) value decreased. CTLA+0.05 wt.% LBS ceramics sintered at 1320°C for 4h exhibited the optimal microwave dielectric properties of dielectric permittivity (ε_r) = 45.02, quality factor (Q×f) = 37400 GHz, and temperature coefficient of resonant frequency (τ_f) = 9.84 ppm/°C.