Mg0.95Ni0.05TiO3 ceramics were prepared by traditional solid-state route using sintering temperatures between 1300 and 1425 °C and holding time of 2-8 h. The sintered samples were characterized for their phase composition, micro-crystalline structure, unit-cell constant, and dielectric properties. A two-phase combination region was identified over the entire compositional range. The effect of sintering conditions was analyzed for various properties. Both permittivity (εr) and Q factor (Qf) were sensitive to sintering temperatures and holding times, and the optimum performance was found at 1350 °C withholding time of 4 h. The temperature coefficient of resonant frequency (τf) in a range from -45.2 to -52 (ppm/°C) and unit-cell constant were not sensitive to both the sintering temperature and holding time. An optimized Q factor of 192,000 (GHz) related with a permittivity (εr) of 17.35 and a temperature coefficient (τf) of -47 (ppm/°C) was realized for the specimen sintered at 1350 °C withholding time of 4 h. For applications of 5G communication device (filter, antennas, etc.), Mg0.95Ni0.05TiO3 is considered to be a suitable candidate for substrate materials.
Keywords: Mg0.95Ni0.05TiO3; low-loss ceramics; microwave performances; sintering temperature.