The origin of spin current in YIG/nonmagnetic metal multilayers at ferromagnetic resonance
The origin of spin current in YIG/nonmagnetic metal multilayers at ferromagnetic resonance
复制标题
铁磁共振下 YIG/非磁性金属多层中自旋电流的起源
DOI：
10.1088/1674-1056/26/4/047202
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发表时间：
2017
影响因子：
1.7
通讯作者：
Wu Yon
中科院分区：
文献类型：
--
作者：
Kang Yun;Zhong Hai;Hao Runrun;Hu Shujun;Kang Shishou;Liu Guolei;Yan Shishen;Yu Shuyun;Han Guangbing;Mei Liangmo;Kang Yun;Zhong Hai;Hao Runrun;Hu Shujun;Kang Shishou;Liu Guolei;Yan Shishen;Yu Shuyun;Han Guangbing;Mei Liangmo;Zhang Yin;Wang Xiangrong;Wu Yon
铁磁共振（FMR）条件下钇铁石榴石（YIG）/非磁性金属（NM）层系统中的自旋泵浦是在NM层中产生自旋电流的常用方法。充分了解自旋电流源对于提取纳米粒子的自旋霍尔角和潜在的自旋电子学应用至关重要。人们普遍认为，自旋电流是从进动 YIG 磁化强度泵入 NM 层的。在这里，通过结合薄 YIG/Pt 和 YIG/NM 1/NM 2（NM 1= Cu 或 Al，NM 2= Pt 或 Ta）上的微波吸收和直流电压测量，我们明确地表明，NM 中的自旋电流不是来自进动的 YIG 磁化强度，而是来自磁化的 NM 表面（与薄 YIG 接触），这要么是由于磁邻近效应 (MPE)，要么是由于 YIG 中不可避免的扩散 Fe 离子到新墨西哥州。这个结论是通过分析 FMR 微波吸收峰和逆自旋霍尔效应 (ISHE) 的直流电压峰得出的。电压信号归因于磁化的纳米材料表面，在传统的FMR实验中很难观察到，并且当电检测电路打开时被大大放大。
Spin pumping in yttrium-iron-garnet (YIG)/nonmagnetic-metal (NM) layer systems under ferromagnetic resonance (FMR) conditions is a popular method of generating spin current in the NM layer. A good understanding of the spin current source is essential in extracting spin Hall angle of the NM and in potential spintronics applications. It is widely believed that spin current is pumped from precessing YIG magnetization into NM layer. Here, by combining microwave absorption and DC-voltage measurements on thin YIG/Pt and YIG/NM 1/NM 2 (NM 1= Cu or Al, NM 2= Pt or Ta), we unambiguously showed that spin current in NM, instead of from the precessing YIG magnetization, came from the magnetized NM surface (in contact with thin YIG), either due to the magnetic proximity effect (MPE) or from the inevitable diffused Fe ions from YIG to NM. This conclusion is reached through analyzing the FMR microwave absorption peaks with the DC-voltage peak from the inverse spin Hall effect (ISHE). The voltage signal is attributed to the magnetized NM surface, hardly observed in the conventional FMR experiments, and was greatly amplified when the electrical detection circuit was switched on.