钛酸锶陶瓷晶界结构与性能的调控

项目名称： 钛酸锶陶瓷晶界结构与性能的调控

项目编号： No.51202272

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 无机非金属材料学科

项目作者： 邢娟娟

作者单位： 中国科学院上海硅酸盐研究所

项目金额： 25万元

中文摘要： 钛酸锶被称作电子陶瓷的模型材料，然而针对具有实际应用意义的钛酸锶陶瓷晶界的研究远不如结构较为简单的双晶晶界那么深入。本项目以分析电子显微镜为主，结合其它表征手段，多层次定性定量系统分析典型施受主掺杂钛酸锶陶瓷的晶界特征，包括晶界结构、成分、晶体学取向等。结合材料的微结构特点如晶粒尺寸、掺杂元素在晶粒内的固溶等，推演不同类型晶界的形成机制，建立不同类型晶界与晶粒生长间的动力学关系；另一方面，根据介电、复阻抗谱的表征测试，结合晶界成分的定量分析结果及原子键合状况，研究与空间电荷相关的特征弛豫过程，以及不同类型晶界对外加电场的响应机制，建立合适的模型，阐明不同类型的晶界对材料电学性能的贡献。研究结果有助于我们通过晶界的设计实现对材料微结构、性能的调控。本项目的特色之处在于分析电镜的定量研究将晶界的结构、成分及空间电荷分布等信息结合起来，把对材料微结构与性能关系的认识提高到更新更深的层面。

中文关键词： 钛酸锶；氧化锌；晶界；分析电镜；

英文摘要： Strontium titanate is regarded as the model material for electronic ceramics.Comparing with the bicrystal grain boundaries with simple structures,the grain boundaries in strontium titanate ceramics are more complicated and less deeply studied although they show more practical significance.In this study, the grain boundary characteristics including structure, composition, crystallographic orientations in typical donor and acceptor doped strontium titanate ceramics will be qualitatively and quantitatively analyzed by mainly using analytical electron microscopy.Combining with the microstructural features of the materials such as the grain size, the dopant solution in grain, the formation mechanisms of different types of grain boundaries will be proposed. The kinectics for grain growth related to different types of grain boundaries will be established. On the other hand, associating with the quantitative analysis of grain boundary compositions and the bondings of the atoms,the space charge related characteristic relaxations and the response mechanisms of different types of grain boundaries to the external electric field will be studied by the dielectric property measurements and the impedance spectroscopy. A proper model will be established to clarify the contributions of different types of grain boundaries to the

英文关键词： Strontium titanate；zinc oxide；grain boundary；analytical electron microscopy；