Transition Metal and Rare Earth Doped Sb2Te3 and Bi2Te3 Diluted Magnetic Semiconductors

过渡金属和稀土掺杂 Sb2Te3 和 Bi2Te3 稀磁半导体

• 批准号: 0604549
• 负责人: Ctirad Uher
• 金额: --
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0604549&HistoricalAwards=false
• 关键词: Transition; Metal; Rare; Earth; Doped

Technical: This project seeks new knowledge and greater understanding of the ferromagnetic state in Sb2Te3 and Bi2Te3. Little is known about the magnetic properties upon doping these materials. The approach of this project is to investigate: (i) the upper limits of incorporation of transition metal (TM) magnetic impurities in thin films of Sb2Te3 and Bi2Te3, (ii) the nature of the TM impurity centers in the host lattice, and (iii) the influence of charge carrier density on the magnetic state of the structure. Ultrafast spin dynamics studies will be used to assess fundamental interaction parameters such as the exchange integrals Jsp,d and Jd,d that govern the coupling energy between the TM ions and carriers, and between TM ions themselves. Additionally, studies of the influence of rare earths and their partially filled f-orbitals on stimulating magnetic interactions in Sb2Te3 and Bi2Te3 will be explored. It is expected, that since the orbital moment is not quenched, the s, p-f exchange interactions may be stronger which could lead to higher Curie temperature provided enough of the rare earth ions can be incorporated in the thin film matrix and antiferromagnetic superexchange is not too strong. Non-Technical: The project addresses basic research issues in a topical area of materials science having high technological relevance. The research will contribute basic materials science knowledge at a fundamental level to new understanding and capabilities for potential next generation electronic/spintronic devices. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. The project provides a rich training ground (MBE growth, structural, transport, and magnetic characterization) for graduate and undergraduate students in areas that have technological significance. Aspects of this research are presented to graduate students as part of regularly scheduled colloquia and the topic of spintronics is incorporated to enliven the curriculum of an introductory physics course. The project is cofunded by the DMR Electronic Materials and Condensed Matter Physics Programs.

技术：该项目寻求新的知识和对SB2TE3和BI2TE3中铁磁状态的新知识和更多了解。关于掺杂这些材料时的磁性特性知之甚少。该项目的方法是研究：（i）在SB2TE3和BI2TE3薄膜中掺入过渡金属（TM）磁杂质的上限，（ii）宿主晶格中TM杂质中心的性质，以及（iii）电荷载体密度对结构磁性状态的影响。超快自旋动力学研究将用于评估控制TM离子和载体之间以及TM离子本身之间的耦合能量的基本相互作用参数，例如Exchange积分JSP，D和JD，D。此外，将探讨稀有地球及其部分填充的F-轨道对SB2TE3和BI2TE3中刺激磁相互作用的影响的研究。预计，由于轨道矩没有被淬灭，因此S，P-F交换相互作用可能更强，如果可以将足够的稀土离子纳入薄膜矩阵中，并且反铁磁性superexchange不太强。非技术：该项目解决了具有高技术相关性的材料科学局部研究领域的基础研究问题。这项研究将在基本层面上为基本材料的知识提供贡献，以实现潜在的下一代电子/自旋设备的新理解和能力。该计划的一个重要特征是通过培训学生在根本和技术意义上的领域中培训研究和教育。该项目为具有技术意义的领域的研究生和本科生提供了丰富的培训（MBE增长，结构，运输和磁性表征）。作为定期安排的座谈会的一部分，将这项研究的各个方面介绍给研究生，并纳入了Spintronics的主题，以使入门物理课程的课程充满活力。该项目由DMR电子材料和冷凝物质物理计划进行了辅助。