Microwave Dielectric Properties of CaTiO3-CaAl1/2Nb1/2O3 Ceramics Doped with Li3NbO4 |
| |
Authors: | Sergey Kucheiko Dong-Hun Yeo Ji-Won Choi Seok-Jin Yoon Hyun-Jai Kim |
| |
Affiliation: | Korea First Microwave Company, Ltd., Kyunggido, Ichon 467–860, South Korea;Thin Film Research Center, Korea Institute of Science and Technology, Seoul 130-650, South Korea |
| |
Abstract: | The microwave dielectric properties of CaTi1? x (Al1/2Nb1/2) x O3 solid solutions (0.3 ≤ x ≤ 0.7) have been investigated. The sintered samples had perovskite structures similar to CaTiO3. The substitution of Ti4+ by Al3+/Nb5+ improved the quality factor Q of the sintered specimens. A small addition of Li3NbO4 (about 1 wt%) was found to be very effective for lowering sintering temperature of ceramics from 1450–1500° to 1300°C. The composition with x = 0.5 sintered at 1300°C for 5 h revealed excellent dielectric properties, namely, a dielectric constant (?r) of 48, a Q × f value of 32 100 GHz, and a temperature coefficient of the resonant frequency (τf) of ?2 ppm/K. Li3NbO4 as a sintering additive had no harmful influence on τf of ceramics. |
| |
Keywords: | microwaves dielectric materials/properties dopants/doping |
|
|