Photo-enhanced magnetization in semiconductors thin films incorporating magnetic dots

包含磁点的半导体薄膜中的光增强磁化

基本信息

批准号：
12450007
负责人：
MUNEKATA Hiroo
金额：
$ 9.22万
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：
2000
资助国家：
日本
起止时间：
2000 至 2003
项目状态：
已结题

项目摘要

Enhancement of magnetization by the light illumination at room temperature (RT) has been reported in the year 2000 for semiconductor-magnetic composite films prepared by the alternative deposition of Fe and GaAs on GaAs(001) substrates at high substrate temperature of 580 "C. While this was a very encouraging achievement for the future applications such as the wireless micro-electronic mechanical system, the origin of the photo-enhanced magnetization (PEM) has remained unclear. It was partly because of the fact that those samples consisted of polycrystalline, granular structures whose constituent ingredients were not well engineered nor controlled. This research was initiated with the aim to identify the key materials and elucidate the mechanism of PEM.Systematic studies of samples prepared by the alternative deposition of Fe_3Ga_<2-x>As_x and GaAs were carried out with various deposition sequences and different substrate temperatures T_<s-> GaN-based composite structures were also inv … More estigated. It was found that the samples prepared by molecular beam deposition with the stacking the unit of [100-nm GaAs/50-nm Fe_3Ga_<2-x>As_x/100-nm GaAs] at T_s = 600℃ exhibit significant PEM effect. Metallurgical evaluation by nano-electron probe analysis has revealed that metamagnetic metal Fe_3Ga_4 is responsible for the observed PEM. It was discussed that this compound was formed as a consequence of the interlayer diffusion process between GaAs and Fe_3Ga_<2-x>As. The hypothesis of the inter-particle interaction model, which was introduced at the initial stage of the study in 2000. was found not to be the principle mechanism for the observed PEM effect.Systematic studies on power dependence of PEM suggest that the increase of magnetization is primarily dominated by the light-induced heating, whereas pure photonic excitation may also contribute the PEM, as manifested itself by the fact that the magnitude of PEM exceeds beyond the maximum value that can be expected from simple heating. This novel effect should be pursued in the future work. Less

2000年报道了在580℃的高衬底温度下在GaAs(001)衬底上交替沉积Fe和GaAs制备的半导体磁性复合薄膜通过室温(RT)光照射增强磁化强度。虽然这对于无线微电子机械系统等未来应用来说是一个非常令人鼓舞的成就，但光增强磁化 (PEM) 的起源仍不清楚，部分原因在于。事实上，这些样品属于多晶颗粒结构，其组成成分没有得到很好的设计和控制。本研究的目的是确定关键材料并阐明质子交换膜的机理。对 Fe_3Ga_ 交替沉积制备的样品进行系统研究。 <2-x>As_x 和 GaAs 采用不同的沉积顺序和不同的衬底温度 T_<s-> GaN 基复合结构进行了评估，结果发现样品。采用分子束沉积法制备的[100-nm GaAs/50-nm Fe_3Ga_<2-x>As_x/100-nm GaAs]单元在T_s = 600℃下堆叠，通过纳米电子探针评价表现出显着的PEM效果。分析表明，变磁性金属 Fe_3Ga_4 是造成所观察到的 PEM 的原因。据讨论，该化合物是由于层间扩散过程而形成的。 GaAs和Fe_3Ga_<2-x>As的粒子间相互作用模型的假设是在2000年研究初期提出的，但发现并不是所观察到的PEM效应的主要机制。 PEM 的功率依赖性表明磁化强度的增加主要由光诱导加热决定，而纯光子激发也可能对 PEM 做出贡献，这一点可以通过以下事实来证明：PEM 的幅度超过了最大值这种新颖的效果应该在未来的工作中得到实现。