Carrier induced ferromagnetism and its control in III-V diluted magnetic semiconductors

III-V族稀磁半导体中的载流子感应铁磁性及其控制

基本信息

批准号：
08455002
负责人：
OHNO Hideo
金额：
$ 4.8万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

The purpose of this research is to clarify the relationship between magnetism and semiconductor properties such as carrier concentration, and to explore the possibility of control of magnetism by the control of carrier concentration, using III-V based diluted magnetic semiconductor quantum structures. Here, we concentrated mainly on (Ga, Mn) As which we showed earlier that it can be grown by lowtemperature molecular-beam epitaxy and shows hole-induced ferromagnetic order at low temperaturcs.The summary of results is as follows ;1.From magnetotransport measuremens, the dependence of ferromagnetic transition temperature (T_c) and hole concentration (p) of (Ga, Mn) As on the Mn concentration (x) was determined. It is showm that both T_c and p monotonically increase with increase of x up to about 0.05. The highest T_c obtained so far is 110 K for a sample with x=0.053.2.All semiconductor-based ferromagnetic/non-magnetic quantum structures, (Ga, Mn) As/(Al, Ga) As heterostructures were realized. Even in such structures, where the thickness of (Ga, Mn) As layrs is below 10 nm, the ferromagnetic order is preserved.3.From the analysis of the magnetoresistance in the paramagnetic region, the magnitude of exchange interaction (J_<pd>) between magnetic spins and holes was determined. This J_<pd> is shown to be large enough to explain the observed T_c by the well RKKY formula remarkably well.These results strongly indicates that it is possible to control the magnetism of (Ga, Mn) As by changing the carrier concentration of the layrs by electric fields using field effect transistor structures.

这项研究的目的是阐明使用基于III-V的稀释磁性半导体量子结构，磁性与载体浓度等半导体特性（例如载体浓度）之间的关系。 Here, we concentrated mainly on (Ga, Mn) As which we showed earlier that it can be grown by lowtemperature molecular-beam epitaxy and shows hole-induced ferromagnetic order at low temperaturcs.The summary of results is as follows ;1.From magnetotransport measuremens, the dependence of ferromagnetic transition temperature (T_c) and hole concentration (p) of (Ga, Mn) As on the确定Mn浓度（X）。据表明，随着X的增加，T_C和P单调增加到约0.05。到目前为止获得的最高T_C对于X = 0.053.2的样品为110 K。所有基于半导体的铁磁/非磁量量子结构，（GA，MN）为/（Al，GA），因为实现了异质结构。即使在这样的结构中，（ga，mn）作为layrs的厚度低于10 nm，也保留了铁磁顺序。3。从磁磁区域中的磁倍率分析中，确定了磁旋转和孔之间的交换相互作用（J_ <pd>）的大小。该J_ <pd>显示出足够大的大小，可以通过良好的配方来解释观察到的T_C。这些结果强烈表明，可以通过使用田间效应晶体管结构来改变电场的载磁（GA，MN）来控制（GA，MN）的磁性。