Ultra low loss microwave dielectric properties of non-stoichiometry [(Mg_0.7Zn_0.3)]_0.95Co_0.05]_1+δ(Ti_1-xSn_x)O_3+δceramics

The prepared [(Mg_0.7Zn_0.3)]_0.95Co_0.05]_1+δ(Ti_1-xSn_x)O_3+δ(δ = 0.02) (x = 0, 0.03, 0.05, 0.07, 0.09, 0.1 and 0.2) ceramics are sintered at 1175-1300°C, the needed sintering temperatures of [(Mg_0.7Zn_0.3)]_0.95Co_0.05]_1+δ(Ti_1-xSn_x)O_3+δ(δ = 0.02) ceramics slightly increased with the increase of Sn⁴⁺content. The sintering characteristics of [(Mg_0.7Zn_0.3)]_0.95Co_0.05]_1+δ(Ti_1-xSn_x)O_3+δ(δ = 0.02) ceramics are developed by the X-ray diffraction patterns and SEM observations to find the influence of sintering temperatures and Sn⁴⁺content on the crystal structure and the grain growth. The influence Sn⁴⁺content and sintering temperatures on the quality values (Q × f) and the temperature coefficient of resonant frequency (τ_fvalues) of [(Mg_0.7Zn_0.3)]_0.95Co_0.05]_1+δ(Ti_1-xSn_x)-O_3+δ(δ = 0.02) ceramics at microwave frequency are well developed in this study. As an optimal compose, [(Mg_0.7Zn_0.3)]_0.95-Co_0.05]_1+δ(Ti_1-xSn_x)O_3+δ(δ = 0.02) successfully demonstrated a dielectric constant of 16.1, a Qxf of 300,000 GHz and a temperature coefficient of resonent frequency value of -53.8 ppm/°C after firing at a relatively lower sintering temperature of 1250°C.