低配位环境稀土离子磁各向异性研究

项目名称： 低配位环境稀土离子磁各向异性研究

项目编号： No.21301136

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： 郭云南

作者单位： 西安交通大学

项目金额： 25万元

中文摘要： "单分子磁体"作为一种分立的、磁学意义上没有相互作用的纳米尺度的磁性粒子一直是基于电子在自旋自由度上的热点研究领域。近年来，稀土离子由于具有显著的磁各项异性，因而成为新一代单分子磁体的"生力军"。然而复杂的晶体场效应阻碍了科学家们合理设计稀土离子单分子磁体的进程。本项目结合当前国内外稀土离子单分子磁体的学科发展前沿，选择具有大空间位阻效应的配体设计低配位环境的稀土材料，通过降低配位数实现稀土离子配位构型的绝对轴对称性,进而研究其与稀土离子磁各向异性的关系。此方案克服了常见的低对称性稀土离子磁各向异性的复杂性，使包括各向异性轴方向和轴向性等方面的研究得以简化。同时，在自选载体上选择电子结构最简单的轻稀土元素，探索轻、重稀土配合物磁各向异性的区别与联系，力争在稀土单分子磁体材料的设计提出规律性的结果，最终为开发新型稀土单分子磁体奠定实验研究基础。

中文关键词： 稀土离子；磁各向异性；单分子磁体；对称性；配体场

英文摘要： Single-molecule magnets (SMMs), where the magnetism is purely of isolated molecular origin rather than intermolecular interaction, has been the ongoing subject of a renovated interest in the field of magnetism and spintronics. Recent investigations demonstrated that lanthanides have attracted significant interest since the pioneering stages of single molecular magnetism because of their unparalleled magnetic anisotropy. However, the complexity of crystal field hampers the process of the rational design of lanthanide based Single Molecule Magnets. In this context, this project centers on the design and synthesis of low-coordinated 4f compounds by virtue of the geometrically constrained and sterically bulky ligands, aiming at designating the metallic centres in a perfectly axisymmetrical coordination sphere to shed light on the relation between the crystal field parameters and the anisotropy. This scheme will be of great help to simplify the complexity of magnetic anisotropy of 4f ions in a low point symmetry and the confirmation of the anisotropy axis and crystal axilarity. It also focuses on the CeIII ion with one electron as a spin sounce to obtain the necessary correlation of the magnetic anisotropy for systems incorporating the light or heavy lanthanide ions, providing an essential regularity and a very promi

英文关键词： Lanthanide；Magnetic anisotropy；Single-molecule magnets；Symmetrical coordination sphere；Coordination field