Fe含量渐变的未充满型钨青铜结构铌酸盐A5(Fe,Nb)10O30的组分设计、缺陷结构及介电性能

铁系钨青铜型铌酸盐A5B10O30在结构上具有强大的调控能力，在功能上具有丰富的介电性能，可以作为一种优秀的载体来探索类钙钛矿材料的成分、结构与性能之间的关系。为了明确这类材料的组分和结构畸变对介电、铁电等物理性能的影响，项目首先对阳离子的组成进行设计，调整不同比例的Fe3+离子和Nb5+离子占据B位，制备Fe含量渐变的系列未充满型钨青铜结构A5(Fe,Nb)10O30(A=Ba, Sr, La, Sm, Eu)铌酸盐陶瓷，其次系统研究成分和缺陷结构（A、B位有序/无序占位情况、Fe含量及价态变化、氧空位）对相变特性（铁电-顺电）、介电性能（弛豫、非弛豫）的影响机制，重点探讨离子占位、缺陷补偿对物理性能的影响规律，在此基础上，选择合适的离子及占位比例，开发具有优良介电性能的铌酸盐陶瓷材料，从而为铁系钨青铜结构铌酸盐陶瓷的性能调控与优化提供理论依据和实验基础。

Iron-serials tungsten bronze type niobates A5B10O30 have strong ability of structure controlling and rich functions of dielectric properties, which can be serve as a good carrier to study the relationship between composition, structure and performance of perovskite-like materials. In order to clarify effect of component and structure distortion on dielectric and ferroelectric properties of these kinds of materials, unfilled iron-serials tungsten bronze structure niobate ceramics with vary iron content will be synthesized though designing cation composition, controlling different proportion of Fe3+ and Nb5+ occupy B site in this application first. And then influence mechanism of composition and defect structure (order/disorder occupation of A and B site, content and valence state of Fe, oxygen vacancy) on dielectric phase transition (ferroelectric-paraelectric) and dielectric properties (relaxation and non-relaxation) will be systematic studied, mainly discussing the influence rule of cation occupation and defect compensation effect on physical properties. On this basis, selecting proper cations and occupied proportion, developing niobate ceramics with excellent dielectric properties, thereby, providing theoretical and experimental base for properties controlling and optimizing of iron-serials niobate ceramics with tungsten bronze structure.