Low temperature sintering and microwave dielectric properties of Zr0.3(Zn1/3Nb2/3)0.7TiO4 ceramics doped with CuO-B2O3

The effects of CuO-B2O3 additive on sintering temperature and microwave dielectric properties of Zr0.3(Zn1/3Nb2/3)0.7TiO4 ceramics prepared by solid-state reaction method have been investigated. The phases and microstructure have also been evaluated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The pure Zr0.3(Zn1/3Nb2/3)0.7TiO4 ceramics show a high sintering temperature of about 1170 °C. However, the addition of CuO-B2O3 lowered the sintering temperature of Zr0.3(Zn1/3Nb2/3)0.7TiO4 ceramics from 1170 to 920 °C due to the CuO-B2O3 liquid-phase.The results showed that the microwave dielectric properties were strongly dependent on densification, crystalline phases and grain size. The Zr0.3(Zn1/3Nb2/3)0.7TiO4 ceramics with the addition of 4.0 wt.% CuO + 4.0 wt.% H3BO3 sintered at 920 °C afforded excellent dielectric properties of e r = 45.8, Q×f =10918 GHz (at 4.5 GHz) and τ f = 45.6 ppm/°C, which represent very promising candidates for LTCC dielectric materials.