Low-temperature sintering and microwave dielectric properties of Li₂Mg₃ZrO₆ ceramics derived from high-energy ball milling

The effects of synthesis temperature, milling time and dwell time on phase formation and phase constitutes of Li₂CO₃–MgO–ZrO₂ mixtures were investigated by high-energy ball milling (HEBM). The Li₂Mg₃ZrO₆ (LMZ) nanopowders were obtained from the mixtures by HEBM 20 h and calcined at 900 °C for 2 h, 300 °C lower than that required by a conventional ball milling method. The sintering characteristics, microstructures and microwave dielectric properties of Li₂Mg₃ZrO₆ ceramics doped with x wt% LiF (0 ≤ x ≤ 8) were investigated. Addition of 6 wt% LiF reduced the sintering temperature of Li₂Mg₃ZrO₆ ceramics to 850 °C, with the fantastic microwave dielectric properties: ε_r = 12.94, Q f = 131,420 GHz, τ_f = − 35.84 ppm/°C. The good effect of LiF on sintering process is due to substitution of F⁻ for O²⁻ and liquid-sintered process.