Phase structure and microwave dielectric properties of (1−x)Li2Zn3Ti4O12−xTiO2 ceramics

Microwave dielectric ceramics with the composition of (1−x)Li2Zn3Ti4O12 (LZT)–xTiO2 (0 ≤ x < 1) were prepared by the solid-state reaction method. The crystal structures were determined by X-ray diffraction. (1−x)LZT–xTiO2 solid solutions show a cubic structure [P4332 (2 1 2)] similar to Zn2Ti3O8 in the range of 0.2 ≤ x ≤0.4. When the x value reaches 0.6, the rutile TiO2 phase appears. The microwave dielectric properties were studied by a Network Analyzer. The relative permittivity (ɛr) and temperature coefficients of resonant frequency (τf) were adjusted with increasing x values. Especially, 0.4LZT–0.6TiO2 ceramic exhibits good microwave dielectric properties with a ɛr of 25.1, a high Q × f of 62,000 GHz and a near-zero τf of −5.2 ppm/°C.