3d过渡族铁磁金属的自旋热输运研究  

Spin Heat Transport of 3d Transition Ferromagnetic Metals

作　　者：张兵兵 杨凡黎 易立志 许云丽[1] 黄秀峰[1] ZHANG Bingbing;YANG Fanli;YI Lizhi;XU Yunli;HUANG Xiufeng(College of Science,China Three Gorges University,Yichang 443002,Hubei,China)

机构地区：[1]三峡大学理学院,湖北宜昌443002

出　　处：《材料导报》2022年第S02期280-283,共4页Materials Reports

基　　金：国家自然科学基金(51371105)。

摘　　要：关于铁磁金属体系中的自旋热输运实验研究,目前遇到的困难有:温度梯度的不均匀、铁磁金属中自旋流的分布不均匀,以及界面的各种散射等,这都会对铁磁金属多层膜体系的自旋塞贝克效应(SSE)产生显著影响,另外,诸多热相关效应引起的干扰信号,也会导致测量结果不准确。以上问题的存在是相关实验研究很少,且实验结果备受争议的原因。这些问题的解决,对于深入理解自旋热输运过程以及成功将自旋塞贝克效应于自旋电子器件中,均具有重要的理论和实践价值。本工作研究了FM/NM、FM_(1)/FM_(2)/NM结构中的纵向自旋塞贝克效应(LSSE),通过差分方法,扣除了研究体系中FM自身的反常能斯特信号和FM自身所产生的逆自旋霍尔效应信号,从而得到了体系的单一自旋塞贝克效应(SSE)信号。在此基础上,进一步研究了SSE信号对温度及铁磁层厚度的依赖关系。结果表明,SSE信号随温度升高而减小,随厚度增加而增大,值得注意的是,相较于单层FM体系,双层FM体系的信号并非各FM层信号的简单叠加;通过与文献的对比研究发现,采用本实验方法提取的SSE信号与理论模型计算值符合较好。The experimental study of spin heat transport in ferromagnetic metal system has encountered great difficulties at present,mainly including the non-uniform temperature gradient,the non-uniform distribution of spin current in ferromagnetic metal,and various scattering at the interface,which will have a significant impact on the spin Seebeck effect of ferromagnetic metal multilayer film system.In addition,the interference signals caused by various thermal correlation effects will also lead to inaccurate measurement results.The existence of the above problems is the reason why there are few relevant experimental studies and the experimental results are controversial.The solution of these problems has important theoretical and practical value for the deep understanding of spin thermal transport process and the successful application of spin Seebeck effect in spin electronic devices.In this paper,the longitudinal spin Seebeck effect(LSSE)in FM/NM and FM_(1)/FM_(2)/NM structures has been studied.Through the difference method,the anomalous Nernst signal of FM and the reverse spin Hall effect signal generated by FM in the studied system have been deducted,and the single SSE signal of the system has been obtained.What’s more,the dependence of SSE signal on temperature and ferromagnetic layer thickness is further studied.The results show that the SSE signal decreases with the increase of temperature and increases with the increase of thickness.It is worth noting that compared with the single-layer FM system,the signal of the double-layer FM system is not a simple superposition of the signals of each FM layer.The comparative study with the literature shows that the SSE signal extracted by the experimental method in this paper is in good agreement with the calculated value of the theoretical model.

关 键 词：3d过渡族铁磁金属 自旋塞贝克效应 反常能斯特效应 逆自旋霍尔效应 

分 类 号：O469[理学—凝聚态物理]