Effect of B2O3-Bi2O3-SiO2-ZnO glass on the sintering and microwave dielectric properties of 0.83ZnAl2O4-0.17TiO2

The 0.83ZnAl(2)O(4)-0.17TiO(2) (ZAT) ceramics were synthesized by solid state ceramic route. The effect of 27B(2)O(3)-35Bi(2)O(3)-6SiO(2)-32ZnO (BBSZ) glass on the microwave dielectric properties of ZAT was investigated. The crystal structure and the microstructure of the ceramic-glass composites were studied by X-ray diffraction and scanning electron microscopic techniques. The low frequency dielectric loss was measured at 1 MHz, The dielectric properties of the sintered samples were measured in the microwave frequency range by the resonance method. Addition of 0.2 wt% of BBSZ improved the dielectric properties with quality factor (Q(u) x f) > 120,000 GHz, temperature coefficient of resonant frequency (tau(f)) = -7.3 ppm/degrees C and dielectric constant (epsilon(r)) = 11.7. Addition of 10 wt% of BBSZ lowered the sintering temperature to about 950 degrees C with Qu x f > 10,000 GHz, epsilon(r) = 10 and tau(f) = -23 ppm/degrees C. The reactivity of 10 wt% BBSZ added ZAT with silver was also studied. The results show that ZAT doped with suitable amount of BBSZ glass is a possible material for low-temperature co-fired ceramic (LTCC) application. (C) 2007 Elsevier Ltd. All rights reserved.