Influence of glass compositions on the microstructure and dielectric properties of low temperature fired BaTi4O9 microwave material with copper electrodes in reducing atmosphere

BaTi4O9 (BT4) dielectric ceramics, containing 10 wt% BaO-ZnO-B2O3-SiO2 (BZBS) glass frit as sintering aid were co-fired with copper paste under reducing atmosphere at 950 degrees C and investigated on microstructures and dielectric properties. Experimental results show the microstructures and microwave dielectric properties of BT4 BZBS glass composite materials are strongly dependent on the Ba-Zn-B-Si ratio, especially for the content of SiO2 addition, in BZBS glass. XRD and EDS results indicate that Cu reacts with BZBS glass-added BT4 ceramics seriously to form complicated reaction products such as BaCuO2 phase, when the BZBS glass composition with lower content of SiO2 (less than 20 wt%), and transformation of some BaTi4O9 into barium titanate with various ratios of Ba/Ti, which, fortunately, does not seriously degrade the dielectric properties. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.