Mechanism of antimony ion doping to optimize microwave dielectric properties of zinc zirconate tantalate ceramic

Abstract

Herein, first-principles calculations predicted the atomic-scale variation of Sb5+ substitution for ZnZrTa2O8, and combined with the solid-phase reaction method to prepare ZnZr(Ta1-xSbx)2O8 (0.0 ≤ x ≤ 0.10) ceramics. ZnZr(Ta0.94Sb0.06)2O8 ceramics demonstrated the optimum microwave dielectric properties after sintering at 1350 °C for 6 h: εr = 24.92, Q × f = 134053 GHz (@7.18 GHz), and τf = −46.21 ppm/°C. For the non-intrinsic factors, the relative density increased from 96.54 % to 97.74 % and the average grain size increased from 19.88 μm to 21.85 μm, both of which reduced the dielectric loss. Regarding intrinsic factors, the progressive elevation of the Raman characteristic peak wave number and the heightened ionicity of Ta/Sb–O bonds predominantly account for the observed enhancement in εr. In addition, the attenuation of lattice vibrational damping behavior, the augmentation in electron cloud density, and the escalation of lattice energy collectively contribute to a decrement in dielectric loss. This study refines the examination of ionic substitution in ZnZrTa2O8 ceramics, offering theoretical insights for optimizing their dielectric properties and promoting their application in microwave communications.