Low-fire BiTaO 4 dielectric ceramics for microwave applications

Abstract

The dielectric properties at microwave frequencies and the microstructures of BiTaO 4 ceramics with 0.5 wt.% doping of CuO have been investigated. The BiTaO 4 ceramics can be sintered to approach 95% theoretical density at 960°C. Sintered ceramic samples were characterized by X-ray and scanning electron microscopy (SEM). The dielectric constant values ( ε r) saturate at 44–45. The Q× f values of 8000–12 000 (at 6 GHz) can be obtained when the sintering temperatures are in the range of 920–960°C. The temperature coefficient of resonant frequency τ f was −40 ppm/°C. The BiTaO 4 ceramics have applications for multilayer microwave devices requiring low sintering temperatures.