Enhanced effect of non-stoichiometry on the sinterability and microwave dielectric properties of Mg_(2+x)SnO_4 ceramics

摘要

Mg_(2+x)SnO_4 microwave dielectric ceramics were prepared by the solid state reaction method. The effect of Mg non-stoichiometry on the sintering behavior, phase structure and microwave dielectric properties of Mg_(2+x)SnO_4 ceramics was investigated. The sinterability and microwave dielectric properties were improved for the samples with slightly excessive amount of Mg (x ≤ 0.15). Especially, the quality factor (Q × f) was significantly enhanced compared with the stoichiometric Mg_2SnO_4 (Q × f = 45, 300 GHz). The best overall performance was obtained for the Mg_(2.15)SnO_4 ceramics sintered at 1,620 ℃ for 4 h (ε_r = 7.42, Q × f= 76,800 GHz, τ_f = -50 ppm/ ℃); this suggests a potential for applications in the millimeter wave range.