Effect of SiO_2 addition on the microstructure and microwave dielectric properties of ultra-low fire TiTe_3O_8 ceramics

摘要

In this study, calcined TiTe_3O_8 powder mixed with different amounts of SiO_2 was sintered at various temperatures. The effect of SiO_2 addition on the densification, microstructural evolution and dielectric properties of TiTe_3O_8 was investigated. Results indicate that SiO_2 addition inhibited the grain growth of TiTe_3O_8 and reduced the evaporation of TeO_2. TiTe_3O_8 ceramics with 1 wt percent SiO_2 addition and sintered at 750 deg C possesses the best dielectric properties: epsilon_r value of 47.6, Q X f value of 48,800, and tau_f value of +152ppm/deg C. Excess SiO_2 addition results in the poor densification and the existence of secondary phase (SiO_2) dissolved in a small amount of TeO_2. They degrade the dielectric properties and trade off the benefit from the SiO_2 addition.