Ultra-high quality factor of Mg6Ti5O16-based microwave dielectric ceramics with temperature stability

Mg6Ti5O16-based ceramics with ultra-high quality factor and temperature stability were prepared by a conventional solid-state reaction route. The effects of Ca2+ on phase composition, microstructure, and microwave dielectric properties of Mg6Ti5O16 ceramics were systematically investigated. X-ray diffraction (XRD) patterns and energy dispersive spectroscopy (EDS) analysis confirmed that the ceramics were composed of MgTiO3, MgTi2O4, and CaTiO3 with all Ca2+ contents. A kind of microwave dielectric ceramics based on Mg6Ti5O16 was developed, and the microwave properties of Mg6Ti5O16 ceramics can be effectively improved by doping of Ca2+. After sintering at 1360 °C for 4 h, Mg6Ti5O16 ceramics doped with x = 0.35 Ca2+ exhibited an ultra-high quality factor of 100432 GHz (at 9 GHz) and a dielectric constant of 19.87. The resonant frequency temperature coefficient was − 3.0 ppm/°C during the temperature range of 25–85 °C. It is a promising material in the field of microwave communication.