A novel temperature-stable and low-loss microwave dielectric composite ceramics Li2Mg3SnO6-SrTiO3

Phase structure, microstructure and microwave dielectric properties of temperature-stable (1 − x)Li2Mg3SnO6-xSrTiO3 (x = 0.08, 0.12, 0.16, 0.20, 0.24, 0.28) composite ceramics were investigated. The results showed that ceramics contain Li2Mg3SnO6 and SrTiO3 phases and well-densified microstructure were obtained at 1375 °C. The microwave dielectric properties strongly depended on SrTiO3 content x. With increasing x, the dielectric constant (εr) increased from 11.0 to 17.0, the quality factor (Q × f) decreased from 105,100 GHz to 30,770 GHz, and the temperature coefficient of resonant frequency (τf) significantly increased from −35.4 ppm/°C to 37.3 ppm/°C. 0.8Li2Mg3SnO6-0.2SrTiO3 composite ceramics displayed a higher relative density of 97.2% and well microwave dielectric properties of εr = 14.2, Q × f = 67,260 GHz, τf = −4.8 ppm/°C.