SPIN ELECTRONICS: Electronic and Magneto-Optic Properties of Rare-Earth and Transition Metal based Materials for Spintronics

自旋电子学：用于自旋电子学的稀土和过渡金属基材料的电子和磁光特性

• 批准号: 0223634
• 负责人: Walter Lambrecht
• 金额: $ 24万
• 依托单位: Case Western Reserve University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0223634&HistoricalAwards=false
• 关键词: SPIN; ELECTRONICS; Electronic; Magneto; Optic

This proposal was received in response to the Spin Electronics for the 21st century Initiative, Program Solicitation NSF-02-036. The proposal focuses on the study of novel magneto-electronic and magneto-optic materials and the computational methods that need to be developed to understand their properties. The potential of alternative magnetic semiconductors based on rare-earth (RE) compounds such as GdN and Transition metal (TM) and/or RE doped semiconducting ScN. Related metallic compounds, such as Mn-N compounds will also be studied. It is anticipated that the different nature of magnetic couplings of RE and TM atoms will enhance the magnetic effects when the two are combined. The main perceived advantage of the class of materials are: 1) full intersolubility because of the common rocksalt structure, 2) the complementary character of TM and RE exchange interactions and magnetic moments, 3) the possibility of n-type based spintronics. Heterostructures of these materials with the compatible high temperature semiconductor GaN will be studied.To develop a better understanding of the origin of magnetism in these and more traditional magnetic semiconductors, a new computational approach is proposed, based on the screened exchange method. This method will be extended to be capable of dealing with both the band gap problem of semiconductors and strongly correlated narrow band open shell systems and will be implemented within the context of the linear muffin-tin orbital band structure method. It will further be made compatible with the non-collinearmagnetism approach based on the rigid spin approximation within atomic spheres.The calculations will provide information on the electronic structure and on the origin and the nature of the magnetism in the systems under study. To validate the new method, it will first be applied to systems for which experimental data are available already and subsequently will be used in a predictive character for new materials. To aid in the comparison with experimental data, magneto-optical properties will be calculated as well as basic electronic structure and magnetic exchange interactions. Extensions of currently available optical calculation methods to incoporate the new screened exchange methodology and its application to magneto-optical properties such as the magneto-optical Kerr effect and the Faraday rotation effectwill be developed.

这项建议是为了响应21世纪的自旋电子学倡议，计划征集NSF-02-036。该提案的重点是研究新型磁电材料和磁光材料，以及需要开发的计算方法来了解它们的性质。基于稀土化合物(如GDN)和过渡金属(TM)和/或稀土掺杂半导体SCN的替代磁性半导体的潜力。相关的金属化合物，如锰氮化合物也将被研究。预计当稀土和Tm原子结合时，不同性质的稀土和Tm原子的磁耦合将增强磁效应。这类材料的主要优点是：1)由于共同的岩盐结构，完全互溶；2)Tm和RE交换作用和磁矩的互补性；3)基于n型自旋电子学的可能性。为了更好地理解这些材料和更传统的磁性半导体材料的磁性起源，提出了一种新的基于屏蔽交换方法的计算方法。这种方法将被扩展到能够处理半导体的带隙问题和强关联的窄带开壳系统，并将在线性松饼-锡轨道能带结构方法的背景下实现。它将进一步与基于原子球内刚性自旋近似的非共线磁性方法相兼容。计算将提供有关电子结构以及所研究系统中磁性的来源和性质的信息。为了验证新方法，它将首先应用于已经有实验数据的系统，随后将用于新材料的预测特征。为了便于与实验数据的比较，将计算磁光性质以及基本的电子结构和磁交换相互作用。将发展现有光学计算方法的扩展，以补充新的屏蔽化交换方法，并将其应用于磁光性质，如磁光克尔效应和法拉第旋转效应。