Effects of Sintering Process on Microstructure and Microwave Dielectric Properties of Ba(Co1/3Nb2/3)O3 Ceramics

Ba(Co1/3Nb2/3)O-3 (BCN) ceramics were prepared using a conventional solid-state route. Effects of sintering on microstructure and microwave dielectric properties of Ba(Co1/3Nb2/3)O-3 ceramics were systematically investigated. Appropriate sintering temperature could restrain the evaporation of CoO and the formation of Nb-rich phase. The dielectric constants and temperature coefficients of resonant frequency changed slightly with the variation in sintering temperatures. The high Q x f value with prolonged sintering time was related to the improvement of 1: 2 ordered arrangement in the B site, rather than the compactness of ceramics. Excellent microwave dielectric properties (epsilon(r) = 32.6, Q x f = 86857 GHz, tau(f) = -14 ppm/degrees C) were obtained in the Ba(Co1/3Nb2/3)O-3 ceramics sintered at 1380 degrees C for 12 h.