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

该研究的目的是开发由半导体材料（硅，III-V和II-VI化合物）和各种磁性材料组成的磁性半导体混合超级结构的制备和设计知识，并根据载流子自旋和磁性离子之间的相互作用寻求新的物理效应。本项目取得的主要成果如下：1）表征了一系列（In，Mn）As基稀磁半导体异质结构，发现了载流子（空穴）浓度和异质结构参数对磁性的强烈依赖性; 2）发现了（In，Mn）As/GaSb异质结构中的光致铁磁性。研究了（In，Mn）As/（Al，Ga）Sb异质结中的磁克尔效应，并对（In，Mn）As/（Al，Ga）Sb异质结中的磁克尔效应进行了研究。研究了（In，Mn）As：MnAs薄膜，发现铁磁MnAs团簇对（In，Mn）As层中的载流子输运有很强的调节作用。7）制备并表征了ZnSe/Fe多层结构，一种新的宽禁带混合超结构，并在磁光光谱中发现了与组成材料无关的新特征。8）考虑了新型磁光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.