受有序空位缺陷调制阻挫系统的第一性原理研究

项目名称： 受有序空位缺陷调制阻挫系统的第一性原理研究

项目编号： No.11274006

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 曹超

作者单位： 杭州师范大学

项目金额： 75万元

中文摘要： 具有磁相互作用竞争关系的正方晶格铁基超导材料与六角晶格的石墨烯一样，都是阻挫系统的典型代表。2010年以来，一类具有空位有序结构的铁基超导材料AyFe(2-x)Se2引起了广泛关注。由于有序空位的存在破坏了完整正方晶格的连接性，对材料中的磁相互作用产生了调制，同时改变了近邻的个数，从而形成了更为复杂的相互作用竞争关系，最终导致其更加丰富的物理性质。本项目申请从第一性原理出发，以AyFe(2-x)Se2材料为主要对象，研究受有序空位调制相互作用阻挫体系中的新电子态和磁性态，以及掺杂和高压对这类系统中电子结构的影响。具体研究包括元素掺杂和元素替代在AyFe(2-x)Se2材料245相中形成的新磁性序，以及其他具有有序空位调制特征的新材料的电子结构和物性。

中文关键词： 第一性原理计算；磁阻挫；自旋轨道耦合；电子关联；

英文摘要： Similar to the hexagonal lattice graphene, square lattice iron-pnictides / chalcogenides are also typical frustrated systems due to the competing magnetic interactions within the system. Since 2010, a new series of iron-chalcogenides, AyFe(2-x)Se2 with ordered vacancy structures has attracted considerable attention. Since the ordered vacancies broke the connectivity of the square lattice, modulated the magnetic interactions, and altered the number of the nearest neighbors, the competition among interactions becomes much more complicated in these materials, which eventually leads to rich physical phenomena and properties. Here, we propose to study the vacancy order modulated frustrated system using the first principles calculations. Employing the AyFe(2-x)Se2 materials as our primary system of interest, it is proposed to study the new electronic states and magnetism, as well as impurity effects and high pressure effects in the vacancy order modulated frustrated systems. New magnetic order due to doping and element substitution in the 245 phase of AyFe(2-x)Se2, as well as the electronic structure and physical properties of other possible vacancy order modulated materials will be studied in detail.

英文关键词： first principles calculation；magnetic frustration；spin-orbit coupling；electron correlation；