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

Microwave dielectric ceramics with the composition of (1-x)Li2Zn3Ti4O12 (LZT)-xTiO(2) (0 <= x <= 1) were prepared by the solid-state reaction method. The crystal structures were determined by X-ray diffraction. (1-x)LZT-xTiO(2) solid solutions show a cubic structure [P4(3)32 (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 (epsilon(r)) and temperature coefficients of resonant frequency (tau(f)) were adjusted with increasing x values. Especially, 0.4LZT-0.6TiO(2) ceramic exhibits good microwave dielectric properties with a epsilon(r) of 25.1, a high Q x f of 62,000 GHz and a near-zero tau(f) of -5.2 ppm/degrees C. (C) 2011 Elsevier B. V. All rights reserved.