A5MO6新型岩盐结构介质材料设计与结构/性能调控机理研究

For the development of microwave devices with lower sintering temperature and ultra-low loss, the novel A5MO6 microwave dielectric materials with rock salt structure are to be prepared by using structure modifications such as six-coordinated A-site using Li+ and Mg2+/Zn2+ ions, six-coordinated B-site using Ti4+, Sn4+, Zr4+, or Mn4+ ion in this project. The results of X-ray diffraction, in-situ Raman spectra, Far-infrared reflection spectrum, and first-principles calculations are employed to explore the relationship between structure and microwave dielectric properties of A5MO6 rock salt structure dielectrics from the perspective of electron-phonon interaction, ionic radius, polarizability, electro negativity, bond valence and packing fraction. Constructing the structures factors and resolving the problem of relationship between the structure/performance for A5MO6 rock salt structure dielectric ceramics. All the results will contribute to better understand the structure-property-relation of A5MO6 rock salt structure dielectrics. The aim is to realize the modification of the constitutions, structure and dielectric properties of A5MO6 rock salt structure dielectrics, and provide theoretical references for exploration new rock salt structure microwave dielectrics with lower sintering temperature and high quality factor.

本项目针对微波元器件对低烧结温度、低损耗的新型微波介质材料的应用需求，拟通过A位离子取代(碱金属离子Li+和二价离子（Mg2+、Zn2+）以2：3比例联合占据六配位A位)、M位离子取代(四价离子Ti4+、Sn4+、Zr4+、Mn4+占据六配位M位)等结构调节方式制备一系列A5MO6新型岩盐结构微波介质材料。利用XRD、原位Raman谱、远红外反射光谱、第一性原理计算等手段从电子-声子相互作用、离子有序度、离子半径、极化率、电负性、键价特性、晶胞原子堆积密度等角度探讨A5MO6型材料晶体结构与微波介电性能间的关系及其调控机理；构建A5MO6型岩盐结构的结构因子，解决其结构/性能间关系问题，实现A5MO6型岩盐结构材料组分、结构与介电性能的可调控性，为开发具有低本征烧结温度和高品质因数的新型岩盐结构微波介质材料提供理论依据。

本项目针对微波元器件对低烧结温度、低损耗的新型微波介质材料的应用需求，对A5MO6型岩盐结构材料，利用A 位离子取代(碱金属离子Li+和二价离子(Mg2+)以2:3比例联合占据六配位A位)、M位离子取代(四价离子Ti4+、Sn4+、Zr4+占据六配位M位)等结构调节方式，成功的制备了一系列A5MO6型Li2Mg3MO6(M=Ti、Sn、Zr)岩盐结构微波介质陶瓷。研究了离子有序度、离子半径、极化率、晶胞原子堆积密度等对Li2Mg3MO6(M=Ti、Sn、Zr)基陶瓷结构及其性能的影响。引入LiF作烧结助剂，在低温液相和晶格活化的共同作用下降低Li2Mg3MO6(M=Ti、Sn、Zr)陶瓷烧结温度至950°C以下。制备了Li2Mg3TiO6-CaF、Li2Mg3TiO6-SrTiO3、Li2Mg3TiO6-Ca0.8Sr0.2TiO3、Li2Mg3SnO6-Ca0.9Sr0.1TiO3、Li2Mg3SnO6-SrTiO3及Li2Mg3ZrO6-CaTiO3等复合陶瓷材料。成功调控了Li2Mg3MO6(M=Ti、Sn、Zr)基陶瓷的微波介电性能，实现了Li2Mg3MO6(M=Ti、Sn、Zr)基陶瓷的低温烧结，获得了一系列Li2Mg3MO6(M=Ti、Sn、Zr)基LTCC材料。本项目还拓展了研究内容，开发了 [Mg0.98(Li0.5Bi0.5)0.02]2SiO4/Ca0.8Sm0.4/3TiO3、Li3Mg2NbO6、Mg0.5Ti0.5NbO4等低介电常数、高Q×f值新型微波介质材料。研究结果发表SCI论文13篇，申请国家发明专利3项(已授权2项)。