Neutron Scattering Studies of Magnetic Semiconductor Thin Films and Nanostructures

9803218 Furdyna教授的更新建议。J.J. Furdyna（圣母大学），J.J. Rhyne（密苏里大学/哥伦比亚大学），C.M. Sorensen教授（堪萨斯州立大学）作为分包商描述了利用中子散射实验研究半导体薄膜和纳米结构的研究，以获得对这些系统中的磁有序和磁相互作用的理解。提出的研究由三个相互关联的领域组成：确定MnSe和mnte基超晶格层间耦合的机制，系统研究以区分应变和稀释对Mn(1-x)IIxIV合金反铁磁跃迁的影响，以及磁性半导体纳米颗粒中自旋有序和交换相互作用的新探索性研究。具体的薄膜体系是MnTe/Zn(1-x)MnxTe超晶格和掺杂值不同的Mn(1- x)MgxTe。还需要研究Mn纳米晶体的磁性。本研究的目的是将中子散射技术应用于磁性半导体薄膜和纳米结构，以了解这些系统中的磁有序和磁相互作用。磁性半导体在磁学中具有重要的基础意义，因为它们的锰亚晶格构成了受短程相互作用支配的受挫海森堡反铁磁体。提出了三个调查领域。首先，将研究磁性/非磁性超晶格，如锰-碲/锌-碲，以阐明磁性层之间相互作用的耦合机制。在第二部分，研究人员将利用新开发的技术来生长由II族和VI族元素组成的材料，特别是与IIa族元素镁和铍组成的材料，以阐明稀释和应变对稀释磁性合金中反铁磁转变的影响。在第三部分，将启动一个探索性试点项目，重点研究含高浓度锰的ii - vi基纳米颗粒中的中子散射。这些研究将由首席研究员Furdyna教授（圣母大学）、联合首席研究员J.J. Rhyne教授（密苏里大学哥伦比亚分校）和分包商堪萨斯州立大学C.M. Sorensen教授合作进行。这些研究有望极大地促进对磁相互作用的理解，从而有助于开发新的和改进的实用设备。＊＊＊

9803218 Furdyna This renewal proposal by Profs. J. Furdyna (University of Notre Dame), J.J. Rhyne (University of Missouri/Columbia), with Prof. C.M. Sorensen (Kansas State University) as a sub-contractor describes research using neutron scattering experiments to study semiconductor thin films and nanostructures in order to gain an understanding of magnetic ordering and magnetic interactions in such systems. The proposed research is composed of three interrelated areas: the identification of mechanisms which determine interlayer coupling in MnSe- and MnTe-based superlattices, systematic investigations to enable distinguishing between the effects of strain and those of dilution on the antiferromagnetic transitions in Mn(1-x)IIxIV alloys, and a new exploratory investigation of spin ordering and exchange interactions in magnetic semiconductor nano-particles. Specific thin film systems are MnTe/Zn(1-x)MnxTe superlattices and Mn(1- x)MgxTe with varying doping values of x. Also to be studied are the magnetic properties of Mn nanocrystals. %%% The objective of this research is to apply neutron scattering techniques to magnetic semiconductor thin films and nanostructures in order to gain understanding of magnetic ordering and magnetic interactions in these systems. Magnetic semiconductors are of great fundamental interest in magnetism, because their manganese sublattices constitute frustrated Heisenberg antiferromagnets governed by short-range interactions. Three areas of investigation are proposed. First, magnetic/non-magnetic superlattices , such as manganese-tellurium/zinc-tellurium will be studied in order to elucidate the mechanisms responsible for the coupling between magnetic layers for magnetic interactions. In the second part the investigators will exploit newly developed techniques for growing materials composed of group II and group VI elements (II-VI all oys), specifically with the group IIa elements magnesium and berillium, in order to elucidate the effect of dilution and strain on the antiferromagnetic transition in diluted magnetic alloys. In the third part an exploratory pilot program will be started that focuses on neutron scattering in II-VI-based nanoparticles containing high concentrations of manganese. These studies will be performed in a collaboration between the principal investigator Prof. Furdyna (University of Notre Dame), the co-principal investigator Prof. J.J. Rhyne (University of Missouri - Columbia), and the sub-contractor Prof. C.M. Sorensen of the Kansas State University. The researches promise to contribute greatly to the understanding of magnetic interactions and thereby assist in the development of new and improved practical devices. ***