Preparation of magnetic-semiconductor hybrid super-structures and exploration of novel physical effects

本研究旨在为由半导体材料（硅、III-V和II-VI化合物）和各种磁性材料组成的磁-半导体杂化超结构的制备和设计提供知识，并基于载流子自旋与磁性离子之间的相互作用寻求新的物理效应。1)表征了一系列（In, Mn） as基稀释磁性半导体异质结构，发现载流子（空穴）浓度和异质结构参数对磁性能有很强的依赖性。2)在（in, Mn） As/GaSb异质结构中发现了光致铁磁性。得出的结论是，这种现象是基于多余的载流子产生的光照射。3)开始用（In, Mn） as基异质结构制造场效应器件。4)重新分析了EXAFS数据，确定了均匀（in, Mn） As中的局部Mn结构（MnAs_4）。5)研究了（in, Mn） As/ (Al, Ga) Sb异质结构中的磁克尔效应，阐明了能带结构与光学响应的关系。6)研究了（In, Mn） As: MnAs薄膜的电学行为，发现铁磁性的MnAs簇可以强烈地改变（In, Mn） As层中的载流子输运。7)制备并表征了新型宽间隙杂化超结构ZnSe/Fe多层结构，并在磁光光谱中发现了与组成材料无关的新特征。8)考虑过新型磁光器件和信息存储器件的概念。

The research has been carried out with the aim to develop knowledge for the preparation and design of magnetic-semiconductor hybrid super-structures composed of semiconductors inaterials (silicon, III-V,and II-VI compounds) and various magnetic materials, and to pursue new physical effects based on the interactions between carrier spins and magnetic ions. Results obtained under this project are summarized as follows :1) Have characterized a series of (In, Mn) As-based diluted magnetic semiconductor heterostructures, and found a strong dependencies of carrier (hole) concentrations and heterostructure parameters on magnetic properties.2) Have found light-induced ferromagnetism in (In, Mn) As/GaSb heterostructures. Have concluded that the phenomenon is based on excess carriers generated by the light irradiation.3) Have initiated the fabrication of field-effect devices with the (In, Mn) As-based heterostructures.4) Have re-analyzed EXAFS data, and determined the local Mn structures (MnAs_4) in homogeneous (In, Mn) As.5) Have studied magneto-Kerr effect in (In, Mn) As/ (Al, Ga) Sb heterostructures, and elucidate the relation between band structures and optical response.6) Have investigated electrical behavior of (In, Mn) As : MnAs thin films, and found that the ferromagnetic MnAs clusters can strongly modify carrier transport in the (In, Mn) As layrs.7) Have prepared and characterized ZnSe/Fe multi-layred structures, a new wide-gap based hybrid super structures, and found new features in magneto-optical spectra which are not due to constituent materials.8) Have considered concepts of novel magneto-optical and information storage devices.