Temperature Stability of Li2TiO3-Zn2SiO4 Microwave Dielectric Ceramics

In this work, microstructure, composition, and microwave dielectric properties of nominal compositions (1-x)Li2TiO3-xZn(2)SiO(4) (x=0.1, 0.2, 0.3, 0.4), which were prepared by conventional solid-state ceramic route, have been investigated. Li2TiO3 and Zn2SiO4 reacted to form Li2ZnSiO4 and Zn2Ti3O8, where Zn2Ti3O8 is formed during Zn2TiO4 cooling. The microwave dielectric properties of samples are mainly affected by the characteristics and relative content of crystal phase and densification. With the increase of x, the relative dielectric constant (epsilon(r)) decreases gradually. The quality factor (Qf) value increases at first, reaches the maximum value at x=0.2, and then decreases. The temperature coefficient of resonance frequency (tau(f)) value has a sharp decrease due to the increase of Li2ZnSiO4. A near zero tau(f) of about -2.0 ppm/degrees C was obtained in 0.8Li(2)TiO(3)-0.2Zn(2)SiO(4) ceramic sintered at 1150 degrees C for 4 h with epsilon(r) value of 17.67, Qf value of 19,600 GHz. Thus, it could be a candidate for microwave devices.