Microstructures and microwave dielectric properties of Li2ZnTi3O8 ceramics prepared by reaction-sintering process

Abstract

The Li2ZnTi3O8 ceramic was prepared by reaction-sintering process and its microwave dielectric properties were investigated. With increasing sintering temperature or dwell time, the relative densities, er values and Q × f values of Li2ZnTi3O8 ceramic increased initially and then decreased. The smaller τf value of Li2ZnTi3O8 ceramic sintered at 975 °C was due to the low degree of oxygen octahedral distortion. When the sintering temperature exceeded 975 °C, the τf values of Li2ZnTi3O8 ceramics were independent of sintering temperature. The tetragonal-shaped grains tend to appear in Li2ZnTi3O8 ceramics sintered at higher temperature and longer dwell time, which was dominated by phase boundary reaction mechanism. Typically, The Li2ZnTi3O8 ceramic sintered at 1,025 °C for 6 h had a maximum relative density of 97.4 % and good microwave dielectric properties of er = 25.8, Q × f = 77,100 GHz, τf = −12.4 ppm/°C. The results show that the reaction-sintering process is a simple and effective method to produce dense Li2ZnTi3O8 ceramics with excellent dielectric properties.