项目名称: 两类多铁性材料(RMnO3 (R=Y或Tb等)和BiFeO3)性能的掺杂对比研究和微结构同步辐射研究
项目编号: No.U1232133
项目类型: 联合基金项目
立项/批准年度: 2013
项目学科: 物理学II
项目作者: 李旗
作者单位: 东南大学
项目金额: 70万元
中文摘要: 近几年来多铁性材料的研究取得了很大的发展。利用它们奇特的物理性质发展新型功能材料和特种复合材料,是自旋电子学发展的基础。RMnO3(R=Y或Tb)和BiFeO3这两类材料均具有多铁性,但是在多铁性的机理和性能的提高上,尚需进一步研究。由于材料的微结构对上述研究起到十分重要的作用,我们计划通过掺杂不同元素或控制样品制备条件制备出不同掺杂的多晶样品或薄膜,改变材料中有关的键长和键角以及磁矩或价态等微结构以利于产生偶极矩和净磁矩,对锰氧化物和BiFeO3这两类材料开展对比研究,测试它们的磁性质,再利用同步辐射XAFS、XRD、XPS以及MXCD等实验技术,研究样品局域原子结构、电子结构和自旋态,分析局域结构在其物性变化中所起的影响,研究掺杂离子的属性(价态、半径大小和离子磁矩)对材料性质和微结构的影响;试图从局域结构的角度探讨产生多铁性的物理机理和改善其性能的有效途径。
中文关键词: 多铁性材料;同步辐射;物理性能;微结构;
英文摘要: In recent years, much progress has been made in the study of multiferoics. Newly developed functional materials and composites based on the unique physical properties of multiferroics are the basis of spintronics. In RMnO3 (R=Y or Tb) and BiFeO3 systems, multoferroicity (coexistence of ferroelectricity, ferromagnetism/antiferromagnetism and/or ferroelasticity, etc.) has been found, however, the mechanism of multiferroicity and their properties improvement still need further investigation. As microstruture of materials plays a crucial role for the above mentioned study, we plan to prepare polycrystalline or film samples by doping different elements or by controlling preparation conditions inorder to induce dipolar electric moment and/or net magnetic moment, and to comparatively study the magnetic and electric properties of doped RMnO3 and BiFeO3, to analyze their local atomic and electronic structures and spin states by synchrotron radiation based XAFS, XRD, XPS and MXCD experiments, and to further study the effects of microstructure on the variation of physical properties, and to investigate the influences of dopants (valence, ionic radius and ionic magnetic moment) on physical properties and microstructure. Insight into microstructure, electronic structure and can provide beneficial information for the study o
英文关键词: multiferroics;synchrotron radiation;physical properties;microstructure;