Microwave Dielectric Properties of LiKSm 2 (MoO 4 ) 4 Ceramics with Ultralow Sintering Temperatures

In this work, a novel low‐temperature firing microwave dielectric ceramic LiKSm 2 (MoO 4 ) 4 was prepared via solid‐state reaction method. Ceramic samples with relative densities about 94.6% were obtained at sintering temperature 640°C–680°C. The best microwave dielectric properties was obtained in ceramic sample sintered at 620°C with a permittivity about 11.5, a Q  ×  f value about 39 000 GHz and a temperature coefficient of frequency about −15.9 ppm/°C. According to XRD patterns and backscattered electron micrograph, combined with Energy Dispersive Spectra analysis, of cofired samples with 30 wt% aluminum sintered at 620°C/4 h, the LiKSm 2 (MoO 4 ) 4 ceramic was found to be chemically compatible with Al but react seriously with Ag, forming AgSmMo 2 O 8 phase, at its sintering temperature.