Laser-induced transient strengthening of coupling in L10-FePt/FeNi exchange-spring film
Laser-induced transient strengthening of coupling in L10-FePt/FeNi exchange-spring film
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DOI：
10.1088/0022-3727/48/14/145002
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发表时间：
2015-03
期刊：
影响因子：
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通讯作者：
Zhifeng Chen;Shufa Li;T. Lai
中科院分区：
文献类型：
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作者：
Zhifeng Chen;Shufa Li;T. Lai
利用延迟磁光极克尔环研究了垂直交换弹簧L10-FePt/FeNi双层膜中耦合态的激光诱导演化。在超快退磁后的~50 ps处，耦合的瞬态强化过程与硬相磁性的显著降低同时发生。磁化强度随时间变化的分析和微磁学计算表明，这种延迟耦合强化现象源于激光对硬磁相和软磁相的调制效应，其中激光诱导FePt相磁各向异性的瞬态降低起着最重要的作用。
Laser-induced evolution of the coupling state in a perpendicular exchange-spring L10-FePt/FeNi bilayer film is studied via time-delayed magneto-optical polar Kerr loops. A transient strengthening process of the coupling is found to occur simultaneously with significant reduction of the hard-phase coercivity at ~50 ps after the ultrafast demagnetization. Analysis of the time-dependent magnetization components and the micromagnetic calculation demonstrate that this delayed coupling-strengthening phenomenon originates from the opposite laser-modulation effects respectively on the hard and soft magnetic phases, in which the laser-induced transient reduction of the magnetic anisotropy in FePt phase plays the most important role.