Low-fired microwave dielectrics in ZnO-TiO2 ceramics doped with CuO and B2O3

The microwave dielectric properties and the microstructure of low-firing zinc titanate ceramics have been investigated. The microstructure of these ceramics have been studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and it was found that CuO addition has the important effect of stabilizing the Zn2TiO4 phase. When the sintering temperatures are in the range of 870-950 degreesC, dielectric constant values (epsilon(r)) saturate at 21-25, the Qxf value is 20 000 GHz (at 10 GHz). The temperature coefficient of resonant frequency (tau(f)) was 10 ppm degreesC(-1). Therefore, the 0.5 wt %-CuO and 1.0 wt %-B2O3 doped ZnO-TiO2 ceramics can be used in multi-layer microwave devices requiring low sintering temperature. (C) 2002 Kluwer Academic Publishers.