Study on magneto-transport properties of semiconductor/magnetic-material heterostructures by ballistic electron emission microscopy

弹道电子发射显微镜研究半导体/磁性材料异质结构的磁输运特性

基本信息

批准号：
13450009
负责人：
YOSHINO Junji
金额：
$ 8.13万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

The aim of this study is to explore the spin-dependent electron tunneling in semiconductor/magnetic-material nano-structures by using ballistic electron emission microscopy and spectroscopy (BEEM/BEES). The major results obtained are as follows.1.We have developed low temperature BEEM/BEES measurement systems, which make it possible that the whole the measurement procedures from sample preparation to LT-MEEM/BEES measurements under ultrahigh vacuum.2.On preparation of novel surface semiconductor/magnetic materials nano-structures(1)We have investigated Fe deposition on GaAs(001) surface with various surface reconstructions, and find that 4x6 reconstructed surfaces give most reliable Shottky contact.(2)In order to clarify the properties of MnAs and CrAs crystallized in zincblende structures, which is expected to have half-metallic band structures based on first principle calculation, surface structure model of GaAs(001) covered with sub-monolayer MnAs was presented based on STM observat … More ions and LEED IV analysis.(3)In order to prepare iron silicide related semiconductor/magnetic materials surface nanostructures, Fe deposition on Si surface was investigated. It was found that Ag-terminated Si(111)√<3>x√<3>-Ag surface allow us to prepare Fe_3Si nano-dot having 10-20 nm in diameter.3.BEES observations of GaAs(001)/Fe Schottky contacts with different Fe layer thickness reveal that electron attenuation length in Fe layers is to be ranging from 1.52 to 2.74 nm depending on electron energy, which is fairly longer than previous reports.4.Careful examination of GaAs(001)c(4x4) surfaces by RHEED rocking curve and LEED IV analysis reveals that GaAs(00l)c(4x4) is not single structure, and have at least two similar but different structures. Furthermore it was demonstrated that phase transition between them can be taken place even at substrate temperatures as low as 300℃ and that confusing behaviors of low temperature MBE growth on GaAs(001)c(4x4) surfaces seems to be well accounted base on its multi-structure nature of c(4x4) surfaces. Less

这项研究的目的是使用弹道电子发射显微镜和光谱学（BEEM/BEES）探索半导体/磁性纳米结构中的自旋依赖性电子隧道。所获得的主要结果如下。1。我们已经开发了低温Beem/Bees测量系统，这使得整个测量程序从样品制备到Ultrahigh真空下的LT-Meem/Bees测量。2。在新型表面半导体/磁性材料结构的新型表面纳米结构（1）中，我们已经研究了差距（1）。重建的表面给出了最可靠的振动接触。（2）为了阐明在锌蓝结构中结晶的MNA和CRA的特性，预计该结构具有基于第一原理计算的半金属条带结构，基于第一个原理的表面结构模型（001）涵盖了基于Subonolayer MNAS的Irrane Irlive Irter Inter Inter Inter Inter Inter Inter Inter Inter Inter Inter Inter（3）。研究了相关的半导体/磁性材料表面纳米结构，在SI表面上的Fe沉积物。 It was found that Ag-terminated Si(111)√<3>x√<3>-Ag surface allow us to prepare Fe_3Si nano-dot having 10-20 nm in Diameter.3.BEES observations of GaAs(001)/Fe Schottky contacts with different Fe layer thickness reveal that electron attenuation length in Fe layers is to be ranging from 1.52 to 2.74 nm depending on electronic energy, which is fairly 4.通过Rheed摇摆曲线和LEED IV分析对GAAS（001）C（4x4）表面进行的较长的检查表明，GAAS（00l）C（4x4）不是单个结构，并且至少具有两个相似但不同的结构。此外，即使在底物温度低至300℃的底物温度下，它们之间的相变也可以进行，并且在GAAS（001）C（4x4）表面上，低温MBE生长的混乱行为似乎在其C（4x4）表面的多结构性质上似乎是很好的基础。较少的