芯-壳结构超高温多层陶瓷电容器介质材料的制备与性能调控

项目名称： 芯-壳结构超高温多层陶瓷电容器介质材料的制备与性能调控

项目编号： No.21501007

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 程花蕾

作者单位： 宝鸡文理学院

项目金额： 20万元

中文摘要： 困扰超高温多层陶瓷电容器介质材料应用的突出问题是介电温度稳定性较差和介电电容较低。针对介电温度稳定性差的问题，申请者提出通过分步式液相法制备芯-壳结构介电陶瓷，按照 Lichtenecher对数叠加原理及介电多峰叠加效应，具有不同居里温度的介质层进行包覆生长后，陶瓷材料介电常数呈现“多峰效应”，介温特性得到改善。在此基础上，本申请通过在芯-壳结构陶瓷钙钛矿的A位引入含6s电子对Bi，以提高铁电材料的极化强度，进而提高其本征介电电容，探索提高高温介电陶瓷介电电容的新途径，并揭示A位6s电子对对其宏观介电电容的影响规律，阐明其影响机制。本项目的完成不仅能够丰富超高温陶瓷电容器介质材料的材料体系，为超高温介电陶瓷的研究探索新的发展方向，而且能够为今后高性能高温铁电陶瓷的组分设计和性能调控研究提供实验和理论支持，为研发高温MLCC提供优秀的候选材料。

中文关键词： 无铅陶瓷；芯-壳结构；介电性能；相结构；微观形貌

英文摘要： 　　Two disadvantages limit the ultra-high temperature multilayer ceramic capacitor (MLCC) applications: firstly, the temperature stability of dielectric properties are poor; secondly, the dielectric permittivity are still not high enough. In order to improve the dielectric temperature stability of the capacitor materials, new core/shell structure grain systems were designed and will be prepared using the hierarchical liquid phase method. Every dielectric layer in the grain has different Curie temperature. When the grain grow layer by layer, its performance will be the stack results of all the dielectric layers according to the Lichtenecher's law and multimodal effect. On this basis, Bi3+ shows a valence electron configuration of 6s26p0, which allows it to hybridize with the surrounding oxygen anions to improve the polarization of the ferroelectric material, and thus to improve its intrinsic dielectric capacitors. Therefore, Bi3+ will be introduced into A-sites of core/shell structure perovskite ceramic to improve the high temperature dielectric permittivity, as well as their interdependent relationships will be systematically and deep investigated. Consequently, this application not only enrich the ultra high-temperature ceramic capacitor dielectric material system but also provide an alternative direction for searching and developing the ultra-high temperature multilayer ceramic capacitor material. In additional, this study provide the experimental and theoretical supports for the design and performance of high performance high-temperature ceramic capacitor dielectric material to meet the ultra high-temperature MLCC applications.

英文关键词： Lead-free ceramics;Core/shell structure;Dielectric properties;Phase transition;Microstructure