Microstructures and Microwave Dielectric Properties of Bi2O3-Deficient Bi12SiO20 Ceramics

Abstract

The Microstructure and microwave dielectric properties of Bi2O3-deficient Bi12SiO20 ceramics were investigated. A small amount of unreacted Bi2O3 phase melted during sintering at 825 degrees C and assisted with densification and grain growth in all samples. The melted Bi2O3 reacted with remnant SiO2 during cooling to form a Bi4Si3O12 secondary phase. The nominal composition of Bi11.8SiO19.7 ceramics sintered at 825 degrees C for 4h had a high relative density of 97% of the theoretical density, and good microwave dielectric properties: epsilon(r)=39, Qxf=74000GHz, and (f) = -14.1ppm/degrees C. Moreover, this ceramic did not react with Ag at 825 degrees C.