Duplex structure in K_0.5Na_0.5NbO₃-SrZrO₃ ceramics with temperature-stable dielectric properties

详细信息    查看全文

• 作者：Zhiyong Liu ; ^{zyliumail@163.com" class="auth_mail" title="E-mail the corresponding author} ; Huiqing Fan ; ^{hqfan3@163.com" class="auth_mail" title="E-mail the corresponding author} ; Shenhui Lei ; Xiaohu Ren ; Changbai Long
• 关键词：KNN-based ; X8R specification ; Core-shell structure ; TEM
• 刊名：Journal of the European Ceramic Society
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：37
• 期：1
• 页码：115-122
• 全文大小：2679 K

文摘

Temperature-stable dielectric properties have been developed in the 0.86 K_0.5Na_0.5NbO₃-0.14SrZrO₃ solid solution system. High dielectric permittivity (ε′ = 2310) with low loss sustained in a broad temperature range (−55–201 °C), which was close to that of the commercial BaTiO₃-based high-temperature capacitors. Transmission electron microscopy with energy dispersive X-ray analysis directly revealed that submicron grains exhibited duplex core-shell structure. The outer shell region was similar to the target composition, whilst a slightly poor content of Sr and Zr presented in the core region. Based on Lichtenecker’s effective dielectric function analysis along with Lorentz fit of the temperature dependence of dielectric permittivity, a plausible mechanism explaining the temperature-stable dielectric response in present work was suggested. These results offer an opportunity to achieve the X8 R specification high-temperature capacitors in K_0.5Na_0.5NbO₃ based materials.