Co基过渡金属合金团簇的结构和磁性理论研究

项目名称： Co基过渡金属合金团簇的结构和磁性理论研究

项目编号： No.21301112

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 吕瑾

作者单位： 山西师范大学

项目金额： 30万元

中文摘要： 结合近期的实验和理论工作，采用第一性原理方法研究过渡金属合金团簇的几何、电子结构和磁性，探究其之间的相互关联规律，阐释现有实验现象并揭示其物理内涵，为合金团簇进行Stern-Gerlach实验检测提供理论指导。在无对称性限制的条件下，充分考虑过渡金属合金团簇的化学有序性，对CoxMny、CoxRhy(7≤x+y≤13)和FexCoyNiz(x+y+z=13)团簇进行理论计算，寻找具有高稳定性大磁矩的最佳化学计量比合金团簇，获得此类合金团簇的磁性剪裁调控规律。开展相同小尺寸Co-Rh，Co-Pt和Co-Mn团簇的自旋非线性磁性和自旋-轨道耦合效应研究工作，分析3d-3d、3d-4d和3d-5d自旋-轨道相互作用对轨道磁性和磁各向异性的影响，全面理解合金团簇几何结构稳定性与磁各向异性能之间的相互关系。检验准束缚态模型对过渡金属合金团簇磁性计算的普适性，预测实验尚未发现的合金团簇磁性质。

中文关键词： 过渡金属合金团簇；化学有序性；几何结构；磁性；密度泛函理论

英文摘要： Based on the latest experimental and theoretical works, the structural, electronic and magnetic properties of transition metal alloy clusters are studied by using ab initio method, aimed to disclose the interplay among these properties, clarify the physical origin of the experimental phenomena, and offer theory guidance for the prospective Stern-Gerlach research. Without any symmetry restriction, the chemical order of the CoxMny，CoxRhy (7≤x+y≤13) and FexCoyNiz (x+y+z=13) structures are fully considered and investigated theoretically to search better stoichiometries of the high stable structure with large magnetic moment, and obtain the general low of control and tailor of their magnetic properties. The noncollinear magnetism and spin-orbit coupling effect of similar Co-Rh，Co-Pt and Co-Mn clusters with small size are also explored, and the spin-orbit interactions of 3d-3d, 3d-4d and 3d-5d as well as their influence to the orbital magnetism and magnetic anisotropy are studied, helped to comprehend the interaction between geometry and magnetic anisotropy energy of transition metal alloy clusters. Significantly, our work also extensively tests the universality of the virtual bond state model, and helps to predict the magnetic behavior of the alloy clusters unidentified in experiments.

英文关键词： Transition metal alloy clusters；Chemical order；Geometry；Magnetism；Density functional theory