Co2FeAl合金薄膜在垂直外磁场下的超快自旋动力学  

Ultrafast spin dynamics in Co_2FeAl alloy film under perpendicular external magnetic field

作　　者：袁启弘 周洁林 黄汉山 梁宇翔 陈桂才 陈志峰[1] YUAN Qi-hong;ZHOU Jie-lin;HUANG Han-shan;LIANG Yu-xiang;CHEN Gui-cai;CHEN Zhi-feng(School of Physics and Materials Science,Guangzhou University,Guangzhou 510006,China)

机构地区：[1]广州大学物理与材料科学学院,广东广州510006

出　　处：《广州大学学报（自然科学版）》2024年第3期65-70,共6页Journal of Guangzhou University:Natural Science Edition

基　　金：广东省自然科学基金资助项目(2020A1515010411);广东省高等教育教学改革资助项目(2019-N466);广州市科技计划资助项目(2023A03J0125);国家级大学生创新训练资助项目(202211078116)。

摘　　要：文章通过使用时间分辨磁光克尔光谱技术研究了Co2FeAl赫斯勒合金薄膜在施加垂直外磁场下的激光诱导超快自旋动力学。实验结果表明,在严格垂直外磁场下同时激发出表面波模和驻波模两种自旋波模式,且均呈现出自旋波频率随磁场增大而减小的特殊现象。此外,通过衰减特性研究发现,驻波模的磁阻尼因子与外磁场并无明显依赖关系,而表面波模的磁阻尼随磁场增大而增大。通过分析表面波模的群速度讨论了该模式磁阻尼外场依赖特性的成因。实验揭示了钴基赫斯勒合金薄膜在严格垂直外磁场下的自旋波动力学性质,对于推进该类材料在新一代自旋电子器件中的应用具有积极意义。This study investigated the laser-induced ultrafast spin dynamics of Co_2FeAl Heusler alloy film under a perpendicular external magnetic field by using the time-resolved magneto-optical Kerr spectroscopy technique.The experimental results indicate that two spin-wave modes,the surface wave mode and the standing wave mode,are excited simultaneously in the strictly perpendicular external magnetic field,and both modes exhibit the special phenomenon of decreasing spin-wave frequencies with increasing magnetic field strength.Furthermore,the analysis of the decay characteristics reveals that the magnetic damping factor of standing wave mode remains constant regardless of the external magnetic field.Conversely,the magnetic damping of surface wave mode increases as the external magnetic field strength increases.The group velocity of the surface wave mode was analyzed to determine the causes of the external field-dependent properties of the magnetic damping of this mode.Our experiment reveals the spin-wave dynamic characteristics of Co-based Heusler alloy film under the strictly perpendicular external magnetic field,which has positive significance for advancing the application of such materials in next-generation spintronic devices.

关 键 词：赫斯勒合金 超快自旋动力学 时间分辨 自旋波模式 

分 类 号：O433[机械工程—光学工程] O469[理学—光学]