Temperature-Compensated LiMgPO4: A New Glass-Free Low-Temperature Cofired Ceramic

The feasibility of LiMgPO4 (LMP) ceramic for low-temperature cofired ceramic (LTCC) application was investigated. The ceramic was prepared by the conventional solid-state ceramic method. The ceramic sintered at 950°C showed a relative permittivity (ɛr) of 6.6 and high quality factor (Qu×f) of 79 100 GHz with a τf of −55 ppm/°C. The relatively large negative τf value was lowered by preparing LMP–TiO2 composite. The composite with 0.12 volume fraction TiO2 showed good microwave dielectric properties: ɛr=10, Qu×f=26 900 GHz, and τf=+1.2 ppm/°C. LMP–TiO2 composite did not react with the commonly used electrode material silver.