二维超薄半导体磁性纳米片的同步辐射研究

项目名称： 二维超薄半导体磁性纳米片的同步辐射研究

项目编号： No.11305172

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： 胡凤春

作者单位： 中国科学技术大学

项目金额： 29万元

中文摘要： 为了满足社会的可持续性发展和建设节约型社会的要求，电子器件亟待进一步小型化。把自旋和电荷结合起来进行信息处理和存储的自旋电子器件有望能够解决这一关键问题，成为当今相关领域的研究热点。本项目拟选择具有良好自旋极化载流子源的II-VI族半导体(如ZnS、ZnSe等)为基质，利用层状杂化中间体辅助的化学方法制备出过渡金属离子(Mn、Co等)掺杂的二维超薄半导体磁性纳米片结构材料，实现对其磁性的调控。利用同步辐射XAFS和XMCD等技术获得磁性离子的微观结构（局域结构和电子结构）和微观磁性（轨道磁距和自旋磁距）特点以及电子自旋性质与形貌、磁性离子组成等因素的关系，从原子分子水平上深刻理解其构效关系以及对磁性离子自旋态的调控作用；结合第一性原理理论计算给出磁性离子的电子态密度，阐明形貌结构、磁性离子组成对其磁性调控的微观物理机制，为探索新的小型化自旋电子学器件的支撑材料提供理论和实验基础。

中文关键词： 磁性纳米材料；同步辐射XAFS 和XMCD；几何形貌；电子结构；磁性调控

英文摘要： To meet the requirements of social sustainable development and construct an economical society, the future electronic devices need to be further minimized. In this respect, the spintronics devices that could simultaneously utilize charge and spin of electrons are likely to solve this crucial problem. In this proposal, we prepare to fabricate two-dimensional(2D) ultrathin magnetic nanosheets of transition-metal ions (Mn, Co) doped II-VI semiconductors (such as ZnS and ZnSe) by use of a lamellar hybrid intermediate strategy. The synchrotron X-ray absorption fine structure (XAFS) and X-ray magnetic circular dichroism (XMCD) spectroscopy are employed to reveal the microstructures (including the local atomic and electronic structures) and micromagnetism (spin and orbital moment) of the magnetic ions in the nanosheets. On the basis of these results, the electron spin properties and its relationship with morphology and ions composition are systematically investiaged. In combination of the first-principles calculations, the structure-activity relationship and the physical mechanisms of the magnetic interactions at the atomicl and molecular levels are clarified. The obtained results will provide solid theoretical and experimental foundations for the new generation of miniaturization spintronics devices.

英文关键词： magnetic nanomaterials；synchrotron XAFS and XMCD；morphology；electronic structures；magnetism manipulation