B‐site internal‐strain regulation engineering of tungsten bronze structural dielectric ceramics

Abstract

AbstractInternal strain is considered to be related to the dielectric loss of tungsten bronze structural ceramics, while its effects often cannot be effectively distinguished from non‐intrinsic factors. To quantitatively determine the influential mechanism of dielectric loss by internal strain, B‐site controllable co‐substituted (Al3+, Ga3+, and Sc3+) Ba4Nd9.33Ti18O54 ceramics with single phase were designed and synthesized, and the ratio is designed with the equivalent radius of substituted ions is equal to Ti4+. Through calibrating the global instability index, the relatively straightforward relationship between internal strain and Q×f value is established. As a result, a loss gradient (Q×f value from 8468 to 14311 GHz) and an almost stable real part of permittivity (εr ∼ 68 with near‐zero τf) can be obtained. Not only does it provide direct evidence for the effectiveness of internal strain control on dielectric loss, but also decouples three key parameters of microwave dielectric ceramics, which may be of great significance in future device physics, especially for all‐ceramic non‐Hermitian devices.