Development of galvanomagnetic and magneto-optical devices with III-V-based diluted magnetic semiconductors

开展这项研究的目的是发展由半导体材料(硅、III-V化合物和II-VI化合物)和各种磁性材料组成的磁性-半导体杂化超结构的制备和设计知识，并追求基于载流子自旋和磁性离子相互作用的新的物理效应。1)研究了一系列(In，Mn)As基稀磁半导体异质结，发现载流子(空穴)浓度和异质结参数对磁性有很强的依赖关系。2)在(In，Mn9As/GaSb)异质结中发现了光感应铁磁性。4)对EXAFS数据进行了重新分析，确定了均匀的(In，Mn)As中的局域Mn结构(MnS_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，7)制备并表征了一种新型的基于宽禁带的混合超结构--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)研究了新型磁光存储器件的概念。

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 materials (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 9 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.