Low-firing and microwave dielectric properties of Ba2Ti9O20 with BaO-B2O3-ZnO glass addition

A low-firing ceramic material was fabricated by sintering a mixture of Ba2Ti9O20 with a BaO-B2O3-ZnO (BBZ) glass between 830 and 940 degrees C for 2 h, and the effects of BBZ glass additives on the sintering behavior and microwave dielectric properties were investigated. The results of this showy that its the content of glass increased. the sintering temperature of material decreased. The material can be fully sintered at 900-920 degrees C with glass additives higher than 15 wt %. Two main crystalline phases, Ba2Ti9O20 and BaTi(BO3)(2), were found in the ceramics, and the latter was formed by the reaction between Ba2Ti9O20 and the BBZ glass. The dielectric constant epsilon(r) and the temperature coefficient of resonant frequency tau(f) decreased and quality factor Q x f increased as the content of glass additive increased; ceramics containing 20 wt % BBZ glass additive sintered at 900 degrees C had epsilon(r) = 26.6, Q x f = 11952 GHz, tau(f) = -6.6 ppm/-C.