Microwave dielectric properties of LiNb3O8 ceramics with TiO2 additions

The microwave dielectric properties of LiNb3O8 ceramics were investigated as a function of the sintering temperature and the amount of TiO2 additive. LiNb3O8 ceramics, which were calcined at 750 °C and sintered at 1075 °C for 2 h, showed a dielectric constant (ɛr) of 34, a quality factor (Q × f0) of 58,000 GHz and a temperature coefficient of resonance frequency (τf) of −96 ppm/°C, respectively. The density of the samples influenced the properties of these properties. As the TiO2 content increased in the LiNb3O8–TiO2 system, ɛr and τf of the material were increased due to the mixing effect of TiO2 phase, which has higher dielectric constant and larger positive τf. The 0.65LiNb3O8–0.35TiO2 ceramics showed a dielectric constant ɛr of 46.2, a quality factor (Q × f0) of 5800 GHz and a temperature coefficient of resonance frequency τf of near to 0 ppm/°C.