Effects of light irradiation and thermal heating on interlayer coupling in Fe-Si ferromagnetic metal/semiconductor superlattices

光照射和热加热对 Fe-Si 铁磁金属/半导体超晶格层间耦合的影响

基本信息

批准号：
20310078
负责人：
YOSHITAKE Tsuyoshi
金额：
$ 12.73万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2008
资助国家：
日本
起止时间：
2008 至 2010
项目状态：
已结题

项目摘要

Spin-dependent phenomena have recently received much attention. Particularly, interlayer couplings between ferromagnetic layers separated by nonmagnetic metal and insulator spacer layers have been investigated to a large extent since they can induce the spin-dependent scattering of conduction carriers and spin-dependent tunneling, which are exploited for achieving the giant magnetoresistance (GMR) and tunnel magnetoresistance (TMR) effects, respectively. At present, the switching of interlayer couplings is made by applied magnetic fields. In this study, in order to switch them by the other methods such as light irradiation, thermal heating, and current injection, semiconducting interlayers were employed. Actually ferromagnetic Fe_3Si/semiconducting FeSi_2 superlattices were prepared by sputtering and interlayer couplings were attempted to be switched by their methods. Although current in plane (CIP) films exhibited a change in the electrical resistivity for irradiation with a 1.3-μm la … More ser, which was expected to be due to a change in the interlayer coupling from antiferromagnetic (AF) to ferromagnetic (F) coupling, the change in the electrical resistivity was extremely small to be detected. Thus, we adapted current perpendicular plane (CPP) geometry for the detection. Owing to that, the magnetoresistance ratio was enhanced to be approximately 10%. This value is an order of magnitude larger than that of the CIP films. The CPP films exhibited hysteresis loops for the injection current. From the change in the hysteresis loop under magnetic field, the origin of the hysteresis loops was expected to be a change in the interlayer coupling. It was confirmed that the interlayer coupling of the CPP films was obviously changed from AF coupling at room temperature to F coupling at temperatures of lower than 100 K. The CPP films also exhibited temperature-dependent interlayer couplings : AF coupling in a direction perpendicular to the plane induced at room temperature gradually weakened with a decrease in temperature and it finally disappeared at low temperatures. Less

旋转抑郁现象最近最近的音乐。互联网耦合的座席是通过磁场进行的。通过他们的方法，MS的电阻变化以用1.3-μmla ...更多的ser，这是由于隔间耦合从抗firogerom（F）造成的（F）。）耦合，对电阻率的变化非常小，因此我们适应了垂直平面（CPP）。注入电流的环将是一个变化的层间耦合。当时是当时是当时是当时是当时是当时是当时是从室温下的AF耦合变为在低于100 k的温度下的f耦合。 CPP膜还表现出依赖温度的层间耦合：在垂直于在室温下诱导的平面的方向逐渐减弱，温度降低，最终在低温下消失了