Microwave dielectric properties of Bi2O3-doped Ca[(Li1/3Nb2/3)1−xTix]O3−δ ceramics

The effect of the additive on the densification, low temperature sintering, and microwave dielectric properties of the Ca[(Li1/3Nb2/3)1−xTix]O3−δ(CLNT) was investigated. Bi2O3 addition improved the densification and reduced the sintering temperature from 1150 to 900 °C of CLNT microwave dielectric ceramics. As the Bi2O3 content increased, the dielectric constant (εr) and bulk density increased. The quality factor (Q·f0), however, was decreased slightly. The temperature coefficient of resonant frequency (τf) shifted to a positive value with increasing Bi2O3 content. The dielectric properties (εr, Q·f0, τf) of Ca[(Li1/3Nb2/3)0.95Ti0.05]O3−δ and Ca[(Li1/3Nb2/3)0.8 Ti0.2]O3−δ with 5 wt.% Bi2O3 sintered at 900 °C for 3 were 20, 6500 GHz, −4 ppm/°C, and 35, 11,000 GHz, 13 ppm/°, respectively. The relationship between the microstructure and dielectric properties was studied by X-ray diffraction (XRD), and SEM.