Crystal structure and microwave dielectric properties of the low dielectric loss ZnZr_{1∿span style='font-style: italic'>x}Sn_xNb₂O₈ ceramics

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• 作者：Lingxia Li ; ^{llx_tju@163.com" class="auth_mail" title="E-mail the corresponding author} ; Shuai Zhang ; Jing Ye ; Xiaosong Lv ; Hao Sun ; Sai Li
• 关键词：Ceramics ; Sintering ; Crystal structure ; Microwave dielectric properties
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：15 May 2016
• 年：2016
• 卷：42
• 期：7
• 页码：9157-9161
• 全文大小：1158 K

文摘

ZnZr_1−xSn_xNb₂O₈ (x=0.10, 0.15, 0.20, and 0.25) ceramics with improved microwave dielectric properties were prepared by conventional mixed oxide route. The effects of Sn⁴⁺ ion substitution on the microwave dielectric properties based on structural characteristics in this system were investigated systematically. Rietveld refinement was used to analyze the structure change of the sintered samples. Microscopic analysis showed that all the samples maintained the ZnZrNb₂O₈ phase with monoclinic structure. With the increase of Sn⁴⁺ content, the dielectric constant decreased attributed to the decrease of ionic polarizability. The Q×f value was dependent on, and increased monotonically with packing fraction. The temperature coefficient of resonant frequency (τ_f) correlated with the variation of bond valence of B-site. The excellent microwave dielectric properties of ε_r=27.37, Q×f=76,814 GHz (where f=7 GHz), and τ_f=−55.09 ppm/°C were obtained for ZnZr_1−xSn_xNb₂O₈ (x=0.20) ceramics sintered at 1275 °C for 6 h.