Important role of magnetization precession angle measurement in inverse spin Hall effect induced by spin pumping
Important role of magnetization precession angle measurement in inverse spin Hall effect induced by spin pumping
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DOI：
10.1063/1.4973704
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发表时间：
2017-01-09
影响因子：
4
通讯作者：
Fukuma, Yasuhiro
中科院分区：
文献类型：
--
作者：
Gupta, Surbhi;Medwal, Rohit;Fukuma, Yasuhiro
本文通过宽带自旋泵浦和逆自旋霍尔效应测量，研究了Ni80Fe20/Pt双层体系中Pt的自旋霍尔角。利用垂直于电荷电流方向的外加磁场的面外激励几何结构来抑制不需要的磁效应。根据各向异性磁阻（AMR）的整流电压和微波功率在共面波导中的传统利用方法，估计了宽激励频率范围（4-14 GHz）下铁磁共振的磁化进动角（θ (C)）。观察到不同方法的θ (C)曲线有显著差异，导致Ni80Fe20/Pt界面处的自旋电流密度估计值变化很大。利用AMR效应估计的自旋电流密度的频率依赖性与逆自旋霍尔电压的频率依赖性相似。我们得到频率不变的自旋霍尔角为0.067+/-0.002。AIP出版社出版。
Here, we investigate the spin Hall angle of Pt in a Ni80Fe20/Pt bilayer system by using a broadband spin pumping and inverse spin Hall effect measurement. An out-of-plane excitation geometry with an application of external magnetic field perpendicular to the charge current direction is utilized in order to suppress unwanted galvanomagnetic effects. Magnetization precession angle (theta(C)) on ferromagnetic resonance for wide excitation frequency range (4-14 GHz) is estimated from the rectification voltage of anisotropic magnetoresistance (AMR) and a conventional method of using the microwave power in a coplanar waveguide. A marked difference in theta(C) profiles for the different methods is observed, resulting in the large variation in estimated values of spin current density at Ni80Fe20/Pt interface. The frequency dependence of the spin current density estimated using the AMR effect is found to be similar to that of the inverse spin Hall voltage. We obtain the frequency-invariant spin Hall angle of 0.067+/-0.002. Published by AIP Publishing.