Element-selectively tracking ultrafast demagnetization process in Co/Pt multilayer thin films by the resonant magneto-optical Kerr effect
Element-selectively tracking ultrafast demagnetization process in Co/Pt multilayer thin films by the resonant magneto-optical Kerr effect
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DOI：
10.1063/5.0005393
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发表时间：
2019-10
影响因子：
4
通讯作者：
Kohei Yamamoto;S. Moussaoui;Y. Hirata;S. Yamamoto;Y. Kubota;S. Owada;M. Yabashi;T. Seki;K. Takanashi;I. Matsuda;H. Wadati
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文献类型：
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作者：
Kohei Yamamoto;S. Moussaoui;Y. Hirata;S. Yamamoto;Y. Kubota;S. Owada;M. Yabashi;T. Seki;K. Takanashi;I. Matsuda;H. Wadati
我们使用 X 射线自由电子激光器在 Pt~N${}_{6,7}$ 和 Co~M${}_{2,3}$ 边缘进行共振极磁光克尔效应测量，研究了铁磁 Co/Pt 薄膜的光致动力学，该薄膜展示了具有元素特异性的垂直磁各向异性。所得结果显示光致退磁时间尺度具有明显的元素依赖性：$\tau_\textrm{demag.}^\textrm{Co}=80\pm60~\textrm{fs}$和$\tau_\textrm{demag.}^\textrm{Pt}=640\pm140~\textrm{fs}$。这种依赖性可以通过电流从 Co 层流过界面而引起的 Pt 原子感应力矩来解释。观察到的 Co 和 Pt 磁化动力学可归因于光致 Co/Pt 薄膜现象（包括全光开关）的特征。
We examined the photo-induced dynamics of ferromagnetic Co/Pt thin films demonstrating perpendicular magnetic anisotropy with element specificity using resonant polar magneto-optical Kerr effect measurements at Pt~N${}_{6,7}$ and Co~M${}_{2,3}$ edges with an x-ray free electron laser. The obtained results showed a clear element dependence of photo-induced demagnetization time scales: $\tau_\textrm{demag.}^\textrm{Co}=80\pm60~\textrm{fs}$ and $\tau_\textrm{demag.}^\textrm{Pt}=640\pm140~\textrm{fs}$. This dependence is explained by the induced moment of the Pt atom by current flow from the Co layer through the interfaces. The observed magnetization dynamics of Co and Pt can be attributed to the characteristics of photo-induced Co/Pt thin film phenomena including all-optical switching.