Structural and dielectric behavior of giant permittivity SrNb_xTi_1−xO₃ ceramics sintered in nitrogen atmosphere

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• 作者：Nana Wang ; Minghe Cao ; ^{caominghe@whut.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Zichen He ; Chunli Diao ; Qi Zhang ; Yaping Zhang ; Jinqiang Dai ; Fanzhou Zeng ; Hua Hao ; Zhonghua Yao ; Hanxing Liu
• 关键词：Nb-doped SrTiO3 ; Solid state reaction ; Microstructure ; Dielectric properties ; Defect-dipoles
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：42
• 期：12
• 页码：13593-13600
• 全文大小：2989 K

文摘

SrNb_xTi_1−xO₃ (0.000≤x≤0.015, SNT) ceramics were prepared via a traditional solid state reaction method and sintered in nitrogen atmosphere at 1530 °C. SrNb_0.003Ti_0.997O₃ ceramics exhibit a giant permittivity of about 40,000 and low dielectric loss of 0.027 measured at room temperature and 1 kHz, which is better than that of SNT ceramics sintered in oxygen atmosphere. The crystalline structure, surface morphology, element valance state and dielectric properties of SNT ceramics were investigated, and the mechanism of this giant permittivity effect was explored. The results indicated that the introduction of Nb⁵⁺ would be the likely reason for the partial reduction of Ti⁴⁺ to Ti³⁺ (Ti⁴⁺∙e${\mathrm{Ti}}^{4+}\bullet \mathrm{e}$) in SNT ceramics. Both Nb⁵⁺ and fully ionized oxygen vacancies caused by oxygen-poor sintering environment contributed to this giant permittivity and low dielectric loss existed in SNT ceramics sintered in nitrogen atmosphere.