Neutron Scattering Studies of Ferromagnetic Semiconductor Superlattices Based on III-V and IV-VI Compounds

9972586 Giebultowicz这是一个凝聚态物理学项目，使用中子衍射和反射来研究由铁磁（FM）和半导体组成的新型异质结构和超晶格（SL）。 衍射测量提供了有关自旋结构和SL层间磁相关性的详细信息。含FM组分的半导体纳米结构是最具实际应用前景的结构。然而，直到最近，只有多层材料制备的强反铁磁（AFM）相互作用。该领域的突破是基于III-V族半导体化合物制备新的外延FM膜和异质结构。这些GaAsMn异质结构和其他材料的潜力，表现出铁磁耦合将作为本项目的一部分进行调查。所有衍射和反射率测量将在位于盖瑟斯堡的NIST中子研究中心进行，马里兰州本研究将为博士后和与本项目相关的研究生提供良好的教育培训。磁性半导体显示出一系列不寻常的性质，这些性质具有极大的根本利益以及在未来技术中的潜在用途。本计画将利用中子散射作为研究半导体与磁性材料组成的磁性超晶格的有力工具。中子技术允许确定组成超晶格的原子层中的磁相互作用和自旋结构。这项工作将集中在材料的相互作用是铁磁的，导致大的磁矩的材料，因此显示出潜在的实际应用。自旋电子学的实际应用依赖于材料中的电输运受磁相互作用的调制，如巨磁阻现象。一些待研究的材料，GaAsMn铁磁体，与现有的半导体技术兼容，并可能导致实际设备。参与这项工作的学生和博士后在基础物理学的一个令人兴奋的领域获得了良好的培训，这对未来的实际应用具有巨大的潜力。所有衍射和反射率测量将在位于盖瑟斯堡的NIST中子研究中心进行，马里兰州

9972586GiebultowiczThis is a condensed matter physics project that uses neutron diffractometry and reflectometry to investigate novel heterostructures and superlattices (SLs) composed of ferromagnetic (FM) and nonmagnetic semiconductors. Diffraction measurements provide detailed information about the spin structures and about the interlayer magnetic correlations in the SLs. Semiconducting nanos-tructures containing FM constituents are the most attractive ones for practical applications. However, until recently only multilayers prepared from materials with strongly antiferromagnetic (AFM) interactions were available. A break-through in this area has been the preparation of new epitaxial FM films and heterostructures based on the Ill-V semiconducting compounds. These GaAsMn heterostructures and additional materials with potential to exhibit ferromagnetic couplings will be investigated as part of this project. All diffraction and reflectivity measurements will be carried out at the Center for Neutron Research at NIST, Gaithersburg., MD. The research will provide excellent education training for the post-doctoral associate and the graduate students associated with the project.%%%Magnetic semiconductors show a range of unusual properties that are of great fundamental interest as well as of potential use in future technologies. This project will use neutron scattering as a powerful tool to investigating magnetic superlattices composed of semiconducting and magnetic materials. The neutron technique allows a determination of the magnetic interactions and spin structures in the atomic layers composing the superlattices. The work will focus on materials where the interactions are ferromagnetic, lead to large magnetic moments in the materials, and hence show potential for practical applications. The practical applications or spintronics field depend on the fact that the electrical transport in the materials is modulated by the magnetic interactions, as in the phenomenon of giant magneto resistance. Some of the materials to be studied, the GaAsMn ferromagnet, are compatible with existing semiconductor technologies, and may lead to practical devices. The students and post-doc involved in this work obtain excellent training in an exciting area of fundamental physics, which has great potential for future practical applications. All diffraction and reflectivity measurements will be carried out at the Center for Neutron Research at NIST, Gaithersburg., MD.