Journal of Advanced Ceramics


tungsten bronze type, high permittivity, microwave dielectric properties


(Ba1−xSrx)4(Sm0.4Nd0.6)28/3Ti18O54 (x = 0.02, 0.04, 0.06, 0.08, 0.1) solid solutions were prepared by the conventional solid-state reaction process. It was found that (Ba1−xSrx)4(Sm0.4Nd0.6)28/3 Ti18O54 ceramics are fully composed of BaSm2Ti4O12 and BaNd2Ti5O14 phases for all the compositions. The increasing x value (0.02 ≤ x ≤ 0.1) in (Ba1−xSrx)4(Sm0.4Nd0.6)28/3Ti18O54 ceramics can not only obtain high Q × f value but also effectively enhance the permittivity (εr). The (Ba1−xSrx)4(Sm0.4Nd0.6)28/3Ti18O54 ceramic with x = 0.08, sintered at 1440 ℃ for 4 h, shows excellent microwave dielectric properties of permittivity (εr) ≈ 93.19, quality factor (Q × f) ≈ 9770.14 GHz (at 3.415 GHz), and almost near-zero temperature coefficient of resonant frequency (τf) ≈ +4.56 ppm/℃.


Tsinghua University Press