Investigation of Microwave Dielectric Properties of (Mg1-xZnx)2SiO4 (0≤x≤1) Ceramics

The phase evolutions, microstructures, and microwave dielectric properties of (Mg1-xZnx)(2)SiO4 (0 <= x <= 1) ceramics were investigated. The XRD results show that Mg2SiO4 and Zn2SiO4 are partly limited solid solution in the systems of (Mg1-xZnx)(2)SiO4 ceramics, due to the large differences between their crystal structures. BESEM images show that with the increases of x, the second phase of MgSiO3 will be suppressed, and the occurrence of liquid phase sintering accelerates the growth of crystal grain and aggradations of glass phase in the boundary of grain. The dielectric constants of (Mg1-xZnx)(2)Sig(4) ceramics gradually increase because of the polarization of Zn2+ ion is larger than that of Mg2+ ion. The microwave properties of (Mg1-xZnx)(2)SiO4 ceramics change with the variant of x value, together with external factors of the secondary phase, porosity and grain size of (Mg1-xZnx)SiO4 ceramics. When x is equal to 0.6, the optimum microwave dielectric properties of (Mg0.4Zn0.6)(2)SiO4 ceramics is obtained; epsilon(r) = 6. 6, Qf = 95650GHz, tau(f) = -60 x 10(-6)/degrees C.