高温高压下典型IV族氧化物MO2(M=C,Si)的相变边界行为与性质研究

项目名称： 高温高压下典型IV族氧化物MO2(M=C,Si)的相变边界行为与性质研究

项目编号： No.11474127

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 李芳菲

作者单位： 吉林大学

项目金额： 90万元

中文摘要： 含有不同成键类型和结构特点的典型IV族氧化物MO2(M=C,Si)具有丰富的相图结构，在它们相变边界附近的行为和性质变化蕴藏了丰富的物理问题，其研究对于深刻理解相变机制等具有重要科学意义，但目前还没有关于此类研究的系统报道。本项目拟采用原位高温高压布里渊与拉曼(红外)散射相结合的可见光谱技术，及同步辐射x射线衍射、吸收、非弹性散射等实验方法和理论模拟计算，通过对单晶态样品的高温高压研究，获得相变边界附近的弹性和晶格振动等行为特征与变化规律，积累在相变边界附近与晶格/电子结构、性质变化有关的高温高压实验数据和现象，总结分子晶体与原子晶体在相变边界附近的弹性、晶格振动等物理参数的变化规律，探索其对相变机制和相变动力学的影响。通过该项目的实施不仅可以加深对高压下典型IV族氧化物的相变边界行为与性质的认知，而且还可以为建立具有普适性的高温高压下相变边界行为及性质研究的新途径提供实验和理论依据。

中文关键词： 相变边界；高温高压；弹性；晶体/电子结构；IV族氧化物

英文摘要： The phase diagram of group IV dioxides MO2(M=C,Si), containing different bonding type and structural characteristics, possesses plenty of high temperature and high pressure (HTHP) structures, so these phase boundary behavior and properties are complicated, and contain numerous physical content and problems. In this project, using in-situ HTHP Brillouin scattering and Raman/infrared scattering spectrum technique, together with synchrotron x ray diffraction, absorption and inelastic scattering techniques and theoretical simulations, the elastic and lattice vibrations of single crystal carbon dioxide and silica would be investigated around the phase boundaries. The HTHP data and phenomenon related with lattice/electronic structure and property change around phase boundaries would be systematically accumulated and analyzed. The feature and variation of physical properties near phase boundary in molecular and ionic crystal, such as elastic, lattice vibration, would be summarized, and their influence on phase transition mechanism and dynamics would be investigated. This research may provide not only a way of getting better knowledge of phase boundary behavior and properties in group IV dioxides, but also the experimental and theoretical base for establishing a universal method to study the phase boundary behavior and properties under HTHP conditions.

英文关键词： Phase boundary;high temperature high pressure;Elasticity;Lattice/Electron structure;MO2(M=C;Si)