Synthesis and Microwave Dielectric Properties of Bi-4(SiO4)(3) Ceramics

Abstract

Bi-4(SiO4)(3) ceramics were synthesized and their microwave dielectric properties were investigated. The Bi12SiO20 second phase was formed at approximately 400 degrees C, while the Bi2O2SiO3 and Bi-4(SiO4)(3) phases started to form at 600 degrees C. The amount of the Bi12SiO20, and Bi2O2SiO3 second phases decreased as the firing, temperature exceeded 650 degrees C. A homogeneous Bi-4(SiO4)(3) phase is-as obtained for the specimen fired at 850 degrees C. For the specimens sintered at 900 degrees C for more than 5 h, high-density Bi-4(SiO4)(3) ceramics were obtained. In particular, the Bi-4(SiO4)(3) ceramics sintered at 900 degrees C for 8 h exhibited the good microwave dielectric properties of epsilon(r) = 14.9, Q x f = 36 101 GHz and tau(f) = -9.42 ppm/degrees C.