Microwave Dielectric Properties of Li2Mg2[WxMo(1−x)O4]3 (0 ≤ x ≤ 1) Ceramics Sintered at Low Temperatures

In this work, Li2Mg2[WxMo(1−x)O4]3 (i.e., 0 ≤ x ≤ 1) ceramics with high Q×f values were successfully fabricated at low temperatures (i.e., ≤ 950°C). The sintered specimens were found to exhibit of a single orthorhombic phase when x ≤ 0.6, whereas a secondary phase of MgWO4 was detected in the specimens when x ≥ 0.8. The ceramic samples exhibited homogenous microstructures and relatively high densities (i.e., > 90%) . In the sample with x = 0.2, outstanding microwave dielectric properties of εr = 8.05, Q×f = 50,780 GHz, and τf = −73.6 ppm/°C were achieved at the sintering temperature of 825°C. Furthermore, no apparent reaction between a Ag electrode and the ceramic matrix was observed during the sintering process. As a result, Li2Mg2[WxMo(1−x)O4]3 ceramics proved to be promising candidate materials for low temperature co-fired ceramic (LTCC) technology.