Microwave Dielectric Properties of Li2(M2+)2Mo3O12 and Li3(M3+)Mo3O12 (M=Zn, Ca, Al, and In) Lyonsite-Related-Type Ceramics with Ultra-Low Sintering Temperatures

In this work, the Li2(M2+)2Mo3O12 and Li3(M3+)Mo3O12 (M=Zn, Ca, Al, and In) lyonsite‐related structures were prepared using a solid‐state reaction method. Single‐phase lyonsite materials were formed for the following compositions Li2Zn2Mo3O12, Li3AlMo3O12, and Li3InMo3O12 ceramics. Whereas, the Li2Ca2Mo3O12 batched compositions produced Li2MoO4 and CaMoO4 phases. All the four ceramics did not react with Ag and Al powders at their optimal sintering temperatures, which will permit the possibility of cofired electrodes with these metallurgies. The Li2Zn2Mo3O12 ceramic can be sintered at 630°C with a relative permittivity of 11.1, a Q×f value of ∼70 000 GHz, and a temperature coefficient of −90 ppm/°C at 14.6 GHz. The Li3AlMo3O12 ceramic sintered at 570°C has a relative permittivity of 9.5, a Q×f value of ∼50 000 GHz, and a temperature coefficient of −73 ppm/°C at 14.1 GHz. The Li3InMo3O12 ceramic sintered at 630°C has a relative permittivity of 9.8, a Q×f value of ∼36 000 GHz, and a temperature coefficient of −73 ppm/°C at 15.0 GHz. These ceramics are a good candidate for the expanding family of ultra‐low temperature cofired ceramic technologies, for filter and substrate applications at the high‐frequency range.