Influence of CaxSr1−x(0⩽x⩽1) Substitution for Zn on Microwave Dielectric Properties of Li2ZnTi3O8 Ceramic as Temperature Stable Materials

A temperature stable Li2Zn0.95(SrxCa1−x)0.05Ti3O8 (0⩽x⩽1) ceramics were fabricated using a conventional solid-state route sintered at 1100 °C for 4 h. The XRD results indicate that the main phase Li2ZnTi3O8 and secondary phase including Sr1Ca1−xTiO3 (0⩽x⩽1) solid solution and TiO2 co-exist in composite and form a stable composite system when the (CaxSr1−x) (0⩽x⩽1) substitutes for Zn of Li2ZnTi3O8 ceramic. As x is increased from 0 to 1, the relative permittivity (εr) increases from 26.65 to 27.12, and the quality factor (Q×f) increases from 63 300 to 66 600 GHz. With the increased of x, the temperature coefficient of resonant frequency (τf) increases from 0.27 to 8.23 ppm/°C, and then decreases to 3.51 ppm/°C. On the whole, the Li2Zn0.95(SrxCa1−x)0.05Ti3O8 (0⩽x⩽1) ceramics show excellent comprehensive properties of middle εr = 25–27, higher Q×f ⩾ 60000 GHz and τf ⩽±8.5 ppm/°C.