Correlation of crystal structure and microwave dielectric characteristics of temperature stable Zn_1−xMn_xZrNb₂O₈ (0.02≤x≤0.1) ceramics

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• 作者：Jinxin Bi ; Changhong Yang ; Haitao Wu ; ^{mse_wuht@ujn.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Zn1&minus ; xMnxZrNb2O8 ; Microwave dielectric properties ; Crystal structure ; Complex bond theory
• 刊名：Ceramics International
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：43
• 期：1
• 页码：92-98
• 全文大小：1184 K

文摘

Wolframite-structured Zn_1−xMn_xZrNb₂O₈ (x=0.02, 0.04, 0.06, 0.08, 0.10) ceramics were synthesized by the conventional solid-state method. The effects of Mn²⁺ substitution on the crystal structure, crystal chemistry and microwave dielectric properties of ZnZrNb₂O₈ were investigated. Bond ionicity, lattice energy and thermal expansion of the ceramics were calculated by the complex chemical bond theory, which were used to investigate the correlation between intrinsic factors and microwave dielectric properties. The ε_r values were dependent on the electronic oxide polarizabilities of Zn_1−xMn_xZrNb₂O₈ ceramics. The Q·f values decreased from 51,300 to 44,900 GHz, which could be explained in terms of packing fraction and lattice energy. The τ_f values were shifted to positive direction with the increase of Mn²⁺ contents, which indicated that the distortion of the [BO6] octahedral was closely related to τ_f values. In addition, thermal expansion coefficient also affected the temperature stability of ceramics. Typically, an excellent microwave dielectric property was obtained in the Zn_0.9Mn_0.1ZrNb₂O₈ with a ε_r of 29.43, an appropriate Q·f of 44,900 GHz and a near zero τ_f of −5.61 ppm/°C.