Improvement in sintering behavior and microwave dielectric properties in CaMgGe2O6 via zn substitution

A series of CaMgGe2O6 ceramics doped with Zn2+ ions were designed and fabricated using the solid-state reaction method. The impact of cation doping on sintering behavior, crystal structure, microstructure, and dielectric properties was systematically investigated. Incorporating Zn2+ ions into the crystal structure optimized the sintering process to enhance densification. Analysis of the crystal structure revealed slight changes in lattice parameters and unit cell volume upon introduction of Zn2+ dopants, indicating successful incorporation without significant alteration to the overall structure. Microstructural characterization revealed that increasing Zn2+ content resulted in a finer microstructure with a more uniform grain size distribution. Furthermore, substitution of Zn2+ effectively reduced dielectric loss in CaMgGe2O6 ceramics while maintaining a stable dielectric constant, making them suitable for high-frequency applications. Among all compositions tested, CaMg0.8Zn0.2Ge2O6 exhibited exceptional performance with a Qxf value reaching 64,980 GHz along with an epsilon(r) of 7.88 and tau(f) of -36.9 ppm/degrees C.