Microwave Dielectric Properties of Li_2TiO_3 Ceramics Doped with ZnO-B_2O_3 Frit

摘要

A type of new low sintering temperature ceramic, Li_2TiO_3 ceramic, has been found. Although it is difficult for the Li_2TiO_3 compound to be sintered compactly at temperatures above 1000℃ for the volatilization of Li_2O, dense Li_2TiO_3 ceramics were obtained by conventional solid-state reaction method at the sintering temperature of 900℃ with the addition of ZnO-B_2O_3 frit. The sintering behavior and microwave dielectric properties of Li_2TiO_3 ceramics with less ZnO-B_2O_3 frit (≤3.0 wt%) doping were investigated. The addition of ZnO-B_2O_3 frit can lower the sintering temperature of the Li_2TiO_3 ceramics, but it does not apparently degrade the microwave dielectric properties of the Li_2TiO_3 ceramics. Typically, the good microwave dielectric properties of ε~r = 23.06, Q×f= 32 275 GHz, τ_f = 35.79 ppm/℃ were obtained for 2.5 wt% ZnO-B_2O_3 frit-doped Li_2TiO_3 ceramics sintered at 900℃ for 2 h. The porosity was 0.08%. The Li_2TiO_3 ceramic system may be a promising candidate for low-temperature cofired ceramics applications.