Superior temperature‐stable dielectrics for MLCCs based on Bi0.5Na0.5TiO3‐NaNbO3 system modified by CaZrO3 |
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| Authors: | Wenxu Jia Yudong Hou Mupeng Zheng Yuru Xu Xiaole Yu Mankang Zhu Kuiyong Yang Huarong Cheng Shuying Sun Jie Xing |
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| Affiliation: | 1. College of Materials Science and Engineering, Beijing University of Technology, Beijing, China;2. Materials R&D Department, Beijing Yuanliu Hongyuan Electronic Technology Company Ltd., Beijing, China |
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| Abstract: | An ultra‐wide temperature stable ceramic system based on (1?x) 0.94(0.75Bi0.5Na0.5TiO3?0.25NaNbO3)?0.06BaTiO3]?xCaZrO3 (CZ100x) is developed for capacitor application in this study. All samples exhibit characteristics of pseudocubic structures in XRD patterns. With CaZrO3 addition, the coupling effect of polar nanoregions (PNRs) is weakening, leading to greatly improved temperature stability of dielectric properties. Among all samples, the most attractive properties are obtained in the composition of CZ10 at <15% variation in dielectric permittivity spanning from ?55°C to 400°C and lower than 0.02 of dielectric loss of between ?60°C and 300°C, accompanied by high DC resistivity (107 Ω m at 300°C, calculated by fitting Jonscher's power law). Furthermore, tentative multilayer ceramic capacitors (MLCCs) composed of CZ10 dielectric and Ag:Pd (70:30) internal electrode layers were fabricated by tape casting and cofiring processes. Temperature‐stable dielectric property in formation of MLCC was successfully realized, with small ΔC/C25°C (<15%) and loss factor (≤ 0.02) between ?55°C and 340°C. Meanwhile, CZ10‐based MLCC showed temperature‐insensitive energy storage density of 0.31?0.35 J/cm3 and high‐energy efficiency of above 77% at 120 kV/cm in the range of ?55 to 175°C. All of these exhibit wonderful temperature‐stable dielectric properties and indicate the promising future of CZ10 dielectric as high‐temperature ceramic capacitors. |
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| Keywords: | capacitor ultra‐high temperature ceramics dielectric materials/properties |
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