Enhanced effect of non-stoichiometry on the sinterability and microwave dielectric properties of Mg sub(2+x) SnO sub(4) ceramics

Mg sub(2+x)SnO sub(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 sub(2+x)SnO sub(4) ceramics was investigated. The sinterability and microwave dielectric properties were improved for the samples with slightly excessive amount of Mg (x less than or equal to 0.15). Especially, the quality factor (Q f) was significantly enhanced compared with the stoichiometric Mg sub(2)SnO sub(4) (Q f = 45, 300 GHz). The best overall performance was obtained for the Mg sub(2.15)SnO sub(4) ceramics sintered at 1,620 degree C for 4 h ( epsilon sub(r) = 7.42, Q f = 76,800 GHz, tau sub(f) = -50 ppm/ degree C); this suggests a potential for applications in the millimeter wave range.