Low-fired (Zn,Mg)TiO₃ microwave dielectrics

A dielectric ceramic comprised of (Zn_1-xMg_x)TiO₃ (x = 0 to x = 0.5) with low sintering temperature and promising microwave properties was prepared by applying a semichemical synthesis route and a microbeads milling technique. X-ray diffractometry and thermal analyses results indicated that the phase stability region of the hexagonal (Zn,Mg)TiO₃ extended to higher temperatures as the amount of magnesium increased. The dielectric properties in this system exhibited a significant dependence on the sintering conditions, especially near the phase decomposition temperature. From 950 °C, the temperature compensation characteristics occurred as the phase composition changed from hexagonal (Zn,Mg)TiO₃ to two phases: (Zn,Mg)₂TiO₄ and rutile. The magnesium content for zero temperature coefficient (τ_f) was approximately 3 mol% at 950 °C; however, τ_f increased with the sintering temperatures because of the shift of the decomposition temperature.