Molecular beam epitaxy and magnetotransport of manganese monosilicide layers on (111) silicon substrates

(111) 硅衬底上单硅化锰层的分子束外延和磁输运

• 批准号: 234487974
• 负责人: Professor Dr. Karl Brunner
• 金额: --
• 依托单位: Lehrstuhl für Experimentelle Physik III
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/234487974?language=en
• 关键词: Molecular; beam; epitaxy; magnetotransport; manganese

We will develop methods for molecular beam epitaxy of Manganese monosilicide (MnSi) layers on Si(111) substrates and characterize the structural, magnetic and magnetotransport properties of these layers. MnSi is a magnetic metal with a cubic B20 crystal structure without inversion symmetry. This results in a complex magnetotransport behavior and a rich magnetic phase diagram which depends on temperature and external magnetic field. The most interesting phase, which consists of a Skyrmion lattice of about 20 nm period, has been recently observed by neutron scattering in bulk MnSi. Our project objectives are the growth of epitaxial MnSi and MnSi/Si layer structures. Fundamental studies of crystal properties and in-plane and cross-plane magnetotransport will be performed. Processing of the material will be developed so that structures with comparable dimensions to the skyrmion lattice can be realized and studied. The interaction of ordered magnetic states and partly spin-polarized current within nanostructures promise novel spintronic effects in this Si-based material system.MnSi/Si(111) layers of high crystal quality can be grown by MBE. A thin MnSi seed layer needs to be formed by an initial solid phase epitaxial process. This seed layer and adequate MBE conditions then enable layer-by-layer growth of MnSi and prevent the formation of other silicide phases. The layers will be characterized and optimized for single crystallinity, smoothness and low defect density. Heteroepitaxy of an epitaxial Si cap layer is intended to prevent formation of Mn oxides and interface defects. An e-beam lithography process for tunneling transport and Hall bar structures with sub-100nm dimensions will be developed. Magnetometry and electronic studies of macroscopic and mesoscopic test structures will be performed and form the foundation to future high quality MnSi/Si(111) spintronic structures.

我们将开发用于在Si（111）衬底上的锰硅化物（MnSi）层的分子束外延方法，并表征这些层的结构、磁性和磁输运性质。MnSi是具有立方B20晶体结构的磁性金属，没有反转对称性。这导致了复杂的磁输运行为和丰富的磁相图，这取决于温度和外部磁场。最有趣的相，其中包括一个Skyrmion晶格约20 nm的周期，最近已被观察到的中子散射体MnSi。我们的项目目标是外延MnSi和MnSi/Si层结构的生长。将进行晶体性质和面内和跨面磁输运的基础研究。将开发材料的处理，以便可以实现和研究与skyrmion晶格尺寸相当的结构。纳米结构中有序磁态和部分自旋极化电流的相互作用，为该Si基材料体系提供了新的自旋电子学效应，利用分子束外延技术可以生长出高质量的MnSi/Si（111）薄膜。薄MnSi晶种层需要通过初始固相外延工艺形成。然后，该种子层和适当的MBE条件能够实现MnSi的逐层生长，并防止形成其他硅化物相。这些层将被表征和优化为单一结晶度、光滑度和低缺陷密度。外延Si盖层的异质外延旨在防止Mn氧化物和界面缺陷的形成。将开发用于隧道传输和亚100 nm尺寸的霍尔条结构的电子束光刻工艺。将进行宏观和介观测试结构的磁学和电子学研究，并为未来高质量MnSi/Si（111）自旋电子结构奠定基础。

项目成果

Twin domains in epitaxial thin MnSi layers on Si(111)

Si(111) 上外延薄 MnSi 层中的孪晶域

• DOI: 10.1063/1.4990284
• 发表时间: 2017
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: M. Trabel;N. V. Tarakina;C. Pohl;J. A. Constantino;C. Gould;K. Brunner;L. W. Molenkamp
• 通讯作者: L. W. Molenkamp