Effects of Cu substitution on microstructures and microwave dielectric properties of Li₂ZnSiO₄ ceramics

¹ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China
² Yangtze River Delta Research Institute of UESTC (Huzhou), Huzhou, 313000, China

^* Corresponding author: zqin747@163.com

Abstract

Herein, the influence of Cu²⁺ substitution on the phase composition, bulk density, microstructures, and microwave dielectric properties of Li₂Cu_xZn_1−xSiO₄ (0 ≤ x ≤ 0.06) ceramics prepared by a solid-state reaction were investigated. The results of XRD and mapping showed that Cu²⁺ substitution can avoid the influence of secondary phase on the properties of samples. According to the analysis of bulk density, microstructure and microwave dielectric properties, a proper amount of Cu substitution not only improved the sintering characteristics of Li₂Cu_xZn_1−xSiO₄ ceramics, reduced the densification temperature from 1250 °C to 950 °C, but also increased the Q×f value. Furthermore, Cu²⁺ substitution also improved the temperature stability of the samples. Particularly, the Li₂Cu_0.04Zn_0.96SiO₄ ceramics sintered at 950 °C for 5 h possessed excellent microwave dielectric properties: ε_r = 5.624, Q×f = 12,764 GHz, and τ_f = −77 ppm/°C, exhibiting a potential for the low temperature co-fired ceramic applications.