Effect of B2O3 on the Sintering Condition and Microwave Dielectric Properties of Bi-4(SiO4)(3) Ceramics

Abstract

B2O3 was added to Bi-4(SiO4)(3) ceramics to aid the densification process at low temperatures (<= 900 degrees C). When the B2O3 content was < 3.0 mol%, a porous microstructure developed for the specimens sintered at 875 degrees C. However, when the amount of B2O3 exceeded 3.0 mol%, the Bi-4(SiO4)(3) ceramics were well sintered even at 875 degrees C for 0.5 h, due to the formation of a liquid phase containing B2O3. The microwave dielectric properties were influenced by the amount of B2O3, and the 3.0 mol% B2O3-added Bi-4(SiO4)(3) ceramic sintered at 875 degrees C for 1 h showed good microwave dielectric properties of epsilon(r)=15.6, Q x f=36 281 GHz, and tau(f)=-22 ppm/degrees C.