低维磁性材料磁晶各向异性的表面和界面效应及其人工调控

项目名称： 低维磁性材料磁晶各向异性的表面和界面效应及其人工调控

项目编号： No.11474245

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： 曹觉先

作者单位： 湘潭大学

项目金额： 92万元

中文摘要： 低维磁性材料是一种重要的智能材料，在特种功能材料中占据重要地位，在军事、民用高新技术领域显示出广阔的应用前景。特别是作为重要的信息存储材料，低维磁性材料在电子信息技术领域占有很重要的地位。随着存储密度的提高，磁性记录单元必须纳米化。然而，阻碍磁记录单元纳米化的主要瓶颈在于微结构单元的超顺磁效应。解决问题的基本途径就是提高微结构单元的磁晶各向异性。微结构的磁晶各向异性主要取决于原子周围环境，因此表面效应、界面效应是影响低维磁性材料各向异性的关键因素。在本项目中将采用我们发展的新方法系统研究不同表面与低维磁性材料的相互作用，通过分析电荷转移等揭示表面、界面效应与低维磁性材料各向异性的耦合关联；研究应变、电场对低维磁性材料各向异性的调控机理，发展调控磁晶各向异性的可行性手段和方法；设计以磁电耦合系数为目标函数的计算软件，设计新型磁电耦合材料，拓展低维磁性材料的应用领域，指导其原理性器件的研制。

中文关键词： 磁性薄膜；微结构；纳米材料；转矩法；磁各向异性

英文摘要： As an important smart material, low-dimensional magnetic material occupied a special position in funcational materials due their potential application in military affair and civil area. Magnetic record and magnetic memory play important roles in informational technology. The greatest expectation for the scientific researchers is the enhancement of the magnetic record density of magnetical medium. However, the super paramagnetism of the supersmall structure blocked the further decreasing size of the magnetic record element. The important subject is to find a magnetic medium with super-large magnetocrystalline anisotropy. In general, the magnetocrystalline anisotropy is determined by the type of the element,the local symmetry, the number of nearest atoms and the distance between the atoms. Hence, the surface and interface effects play key roles in magnetocrystalline anisotropy of low-dimensional magnetic material. In this project, we pay our attention on interface and surface effects on the magnetic anisotropy of low-dimensional magnetic material, especially for the magnetic anisotropy of low-dimensional magnetic material on metallic surface, polar surface and non-polar surface. Furthermore, we will manipulate the magnetic anisotropy through the control of spin-orbit coupling by applying strain and electrical field. With the results of electronic structure, charge distribution, spin and orbital coupling, effect of surface and interface, effect of strain and stress, one can understand the underline physical mechanism for magnetic anisotropy and give advice for the design of original magnetic device. Moreover, we will develop a program to design magnetoelectric materials with high magnetoelectric coupling coeffiecents.

英文关键词： magnetic film;microstructure;nanomaterial;Torque method;magnetocrystalline anisotropy