Geometry dependence on inverse spin Hall effect induced by spin pumping in Ni81Fe19/Pt films
Geometry dependence on inverse spin Hall effect induced by spin pumping in Ni81Fe19/Pt films
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DOI：
10.1103/physrevb.85.144408
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发表时间：
2012-04-12
影响因子：
3.7
通讯作者：
Saitoh, E.
中科院分区：
文献类型：
--
作者：
Nakayama, H.;Ando, K.;Saitoh, E.
定量地研究了铁磁共振驱动自旋泵浦引起的逆自旋霍尔效应（ISHE）的几何效应。我们测量了Ni_（81）Fe_（19）/Pt薄膜的铁磁共振谱和随薄膜尺寸和厚度变化的ISHE感应电动势。ISHE产生的电荷电流强度随着薄膜几何形状的变化而系统地变化，这与ISHE的预测一致。实验结果表明，由自旋泵浦引起的ISHE的Ni_（81）Fe_（19）和Pt厚度依赖性之间存在明显的差异。在Pt厚度不变的情况下，所产生的电荷电流的强度与注入的自旋电流密度成正比，而注入的自旋电流密度随着界面效应引起的Ni_（81）Fe_（19）层中自旋弛豫的增加而减小，与其膜厚成反比。另一方面，反映自旋扩散机制在Pt层中，充电电流显着降低与Pt厚度的减少，而注入的自旋电流密度几乎保持不变。
Geometric effects on the inverse spin Hall effect (ISHE) induced by the spin pumping driven by the ferromagnetic resonance (FMR) have been investigated quantitatively. We measured the FMR spectra and the electromotive force induced by the ISHE with changing the size and the thickness in Ni81Fe19/Pt films. The intensity of generated charge currents due to the ISHE changes systematically with changing the film geometry, which is consistent with the prediction of the ISHE. The experimental results show a clear difference between Ni81Fe19 and Pt thickness dependence of the ISHE induced by the spin pumping. With a constant Pt thickness, the intensity of the generated charge current is kept proportional to that of the injected spin-current density, which decreases with increased spin relaxation in the Ni81Fe19 layer due to interfacial effect, inversely proportional to its film thickness. On the other hand, reflecting the spin diffusion mechanism in the Pt layer, the charge current decreases significantly with the decrease of the Pt thickness, while injected spin-current density is almost kept constant.