Element‐Specific Magnetization Damping in Ferrimagnetic DyCo5 Alloys Revealed by Ultrafast X‐ray Measurements
Element‐Specific Magnetization Damping in Ferrimagnetic DyCo5 Alloys Revealed by Ultrafast X‐ray Measurements
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超快 X 射线测量揭示了亚铁磁 DyCo5 合金中元素特定的磁化阻尼
DOI：
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
I. Radu
中科院分区：
文献类型：
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作者：
R. Abrudan;M. Hennecke;F. Radu;T. Kachel;K. Holldack;R. Mitzner;A. Donges;S. Khmelevskyi;A. Deák;L. Szunyogh;U. Nowak;S. Eisebitt;I. Radu
磁有序材料对超短刺激的动态响应依赖于微观参数，如磁矩、交换和自旋-轨道相互作用。众所周知，在多元磁性合金和化合物中，退磁和自旋转换过程的速度具有元素特有的特征，但磁化衰减被认为是所有组成磁性元素的通用参数，无论它们的自旋-轨道耦合和电子结构如何。本文通过研究高各向异性铁磁DyCo5合金对飞秒激光激发的超快磁化响应，为元素特有的磁阻尼系数提供了实验和理论依据。用飞秒激光泵浦X射线磁性圆二色探针测量和原子自旋动力学(ASD)模拟相结合的从头计算参数，揭示了Dy和Co磁矩的退磁和再磁化动力学特性。这些观测结果得到ASD模拟的充分证实，它们与Dy和Co元素特定的自旋-轨道耦合强度有关，这些强度包含在唯象磁化衰减参数中。这些发现可以作为调整激光驱动的磁性过程的速度和大小的配方，从而允许控制多组分磁性材料的各种动态功能。
The dynamic response of magnetically ordered materials to an ultrashort external stimulus depends on microscopic parameters, such as magnetic moment, exchange, and spin–orbit interactions. Whereas it is well established that, in multicomponent magnetic alloys and compounds, the speed of demagnetization and spin switching processes has an element‐specific character, the magnetization damping was assumed to be a universal parameter for all constituent magnetic elements irrespective of their different spin–orbit couplings and electronic structure. Herein, experimental and theoretical evidence for an element‐specific magnetic damping parameter is provided by investigating the ultrafast magnetization response of a high‐anisotropy ferrimagnetic DyCo5 alloy to femtosecond laser excitation. Strikingly different demagnetization and remagnetization dynamics of Dy and Co magnetic moments is revealed by employing femtosecond laser pump–X‐ray magnetic circular dichroism probe measurements combined with atomistic spin dynamics (ASD) simulations using ab initio calculated parameters. These observations, fully corroborated by the ASD simulations, are linked to the element‐specific spin–orbit coupling strengths of Dy and Co, which are incorporated in the phenomenological magnetization damping parameters. These findings can be used as a recipe for tuning the speed and magnitude of laser‐driven magnetic processes and consequently allow control over various dynamic functionalities in multicomponent magnetic materials.
gadolinium金属中巡回和局部磁矩的不同超快动力学。
影响因子：
16.6
作者：
Frietsch B;Bowlan J;Carley R;Teichmann M;Wienholdt S;Hinzke D;Nowak U;Carva K;Oppeneer PM;Weinelt M
通讯作者：
Weinelt M