Low-temperature sintering and microwave dielectric properties of LiF-doped Ba(Mg1/2W1/2)O3–TiO2 ceramics

• Addition of LiF lowered sintering temperature of Ba(Mg1/2W1/2)O3 ceramics from 1500–1600 °C to 900–975 °C.
• Well densified structures with high Q×f values have been obtained.
• LiF-doped Ba(Mg1/2W1/2)O3–TiO2 composite ceramics were produced.
• A near zero τf value was obtained at 950 °C for 0.96 Ba(Mg1/2W1/2)O3–0.04 TiO2–4.0 wt% LiF ceramic.
• These ceramics were compatible with Ag electrodes.

The Ba(Mg1/2W1/2)O3 (BMW)–x wt% LiF (x = 2.0, 4.0, 6.0, 8.0) ceramics were prepared by a conventional solid-state route. The effects of LiF addition on the sinterability, crystal structure, microstructures and microwave dielectric properties of BMW ceramics were investigated. With an amount of LiF addition, the sintering temperature of the ceramics was reduced to below 960 °C from 1550 °C without degradation of microwave dielectric properties, due to the enhancement of the apparent density at low temperature by liquid phase sintering. On this basis, TiO2 was used to adjust the temperature coefficient of resonant frequency, optimized microwave dielectric properties with εr = 20, Q×f = 48,000 GHz, and τf = 1.2 ppm/°C for 0.96 BMW–0.04 TiO2–4.0 wt% LiF composition. With low sintering temperature and good dielectric properties, these LiF-doped ceramics are promising materials for LTCC integration applications.

The novel (1−y) Ba(Mg1/2W1/2)O3–y TiO2–x wt% LiF composite ceramics sintered at 950 °C exhibited excellent microwave dielectric properties of εr = 20, Q × f = 48,000 GHz, and τf = 1.2 ppm/°C for x = 4.0 and y = 0.04 composition.Figure optionsDownload as PowerPoint slide