硅基铁磁半导体材料制备、微结构和磁学性质研究

项目名称： 硅基铁磁半导体材料制备、微结构和磁学性质研究

项目编号： No.61274016

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 无线电电子学、电信技术

项目作者： 蒋最敏

作者单位： 复旦大学

项目金额： 83万元

中文摘要： 铁磁半导体为自旋电子学的研究开辟了一个新天地，它使得人们可以从能带工程的角度设计自旋电子学新型器件。然而，如何获得真正意义下的或者较高居里温度的铁磁半导体材料仍是目前面临的重大挑战。由于成熟的Si集成电路技术，硅基铁磁半导体的研究具有特别重要的地位。 项目着眼于材料制备过程探索和材料的新型结构设计，提出硅基铁磁半导体材料制备、微结构和磁学性质研究。材料制备方法利用分子束外延技术。主要包括以下两条途径的探索。一条途径基于的界面效应，制备MnSi超薄膜， MnSi/Si等超晶格薄膜。另一条途径基于量子点的尺寸和量子限制效应，以及量子点之间的耦合效应，制备磁性量子点晶体。通过对这些材料的微结构、磁学性质研究，寻找材料微结构、生长工艺和过程与磁学特性三者之间的关系和规律。探索硅基铁磁半导体磁有序的新机制和新型结构。为进一步认识铁磁半导体磁有序机制，提供科学依据和初步的理论阐述。

中文关键词： 铁磁半导体；MnGe量子点；Si-SiGe/MnGe核壳纳米线；分子束外延生长；

英文摘要： Ferromagnetic Semiconductors (FMSs) open up a new research area for spintronics, which allow us to design novel spintronic devices from band engineering point of view. However, how to obtain intrinsic FMSs with high Curie temperatures still remains a great challenge so far. Due to advanced Si integration technology, exploration on Si based FMSs is of particular importance. Based on investigations of fabrication processes and designs of novel structures of materials, the project focuses on the fabrications, microstructures and magnetic properties of Si based FMS materials. The materials will be grown by MBE with two major approaches. One approach is based on interface effects, MnSi ultrathin film and MnSi/Si superlattice films will be explored to be grown epitaxially on Si substrates. The other approach is based on size and quantum confinements of quantum dots (QDs) and the coupling between them, the growth of FMS QD crystals will be investigated. The microstructures and magnetic properties of those materials will be studied. With all results obtained, the microstructures, the growth processes and the magnetic properties of the materials will be correlated. The mechanism for magnetic ordering in Si based FMSs will further be investigated. The novel structures for Si based FMSs will be explored. The work carrie

英文关键词： Ferrmagnetic senmiconductor；MnGe quantum dots；Si-SiGe/MnGe core-shell nanowires；Molecular beam epitaxy growth；