Spin pumping damping and magnetic proximity effect in Pd and Pt spin-sink layers
Spin pumping damping and magnetic proximity effect in Pd and Pt spin-sink layers
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DOI：
10.1103/physrevb.94.014414
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发表时间：
2016-07-12
影响因子：
3.7
通讯作者：
Bailey, W. E.
中科院分区：
文献类型：
--
作者：
Caminale, M.;Ghosh, A.;Bailey, W. E.
我们研究了顺磁层（Pd、Pt）与铁磁 Ni81Fe19 薄膜直接和间接接触所产生的自旋泵浦阻尼。我们发现直接接触 Ni81Fe19/(Pd, Pt) 结中与界面相关的 Gilbert 阻尼增强 Delta α 对重金属自旋下沉层厚度 t(N) 具有近乎线性的依赖性，而当 Ni81Fe19 和 (Pd, Pt) 相距 3 nm Cu 时则观察到指数依赖性。我们将准线性厚度依赖性归因于 Pt、Pd 与 Ni81Fe19 界面附近存在感应矩，并使用 X 射线磁圆二色性测量进行量化。我们的结果表明，纯自旋电流的散射在这些系统中取决于配置，并且不能用单一特征长度来描述。
We investigated the spin pumping damping contributed by paramagnetic layers (Pd, Pt) in both direct and indirect contact with ferromagnetic Ni81Fe19 films. We find a nearly linear dependence of the interface-related Gilbert damping enhancement Delta alpha on the heavy-metal spin-sink layer thicknesses t(N) in direct-contact Ni81Fe19/(Pd, Pt) junctions, whereas an exponential dependence is observed when Ni81Fe19 and (Pd, Pt) are separated by 3 nm Cu. We attribute the quasilinear thickness dependence to the presence of induced moments in Pt, Pd near the interface with Ni81Fe19, quantified using x-ray magnetic circular dichroism measurements. Our results show that the scattering of pure spin current is configuration-dependent in these systems and cannot be described by a single characteristic length.