Laser-Induced Magnetization Dynamics in Interlayer-Coupled [Ni/Co]4/Ru/[Co/Ni]3 Perpendicular Magnetic Films for Information Storage
Laser-Induced Magnetization Dynamics in Interlayer-Coupled [Ni/Co]4/Ru/[Co/Ni]3 Perpendicular Magnetic Films for Information Storage
复制标题
DOI：
10.1021/acsanm.9b01028
复制
发表时间：
2019-07
影响因子：
5.9
通讯作者：
Guanjie Wu;Shaohai Chen;Yang Ren;Q. Jin;Zongzhi Zhang
中科院分区：
文献类型：
--
作者：
Guanjie Wu;Shaohai Chen;Yang Ren;Q. Jin;Zongzhi Zhang
利用飞秒脉冲激光快速控制磁化方向是实现先进信息存储技术的有效途径。本文采用时间分辨磁光克尔效应方法，研究了[Ni/Co]4/Ru(tRu)/[Co/Ni]3垂直磁性薄膜的层间耦合效应对磁化动力学的影响。通过控制反铁磁（AF）层间耦合场Hex和外磁场H，我们得到了激光激发下明显不同的动态行为。首先，在2 ps的短时间延迟内，可发生Kerr信号的不变、超快增加或减少三种退磁过程。其次，在弛豫过程中，af耦合样品除了出现正常的相干进动外，还出现了幅值和频率强烈依赖于Hex和h的非同相模式，这两种模式的h依赖频率曲线可以用推导出的解析表达式很好地解释。
Rapid manipulation of magnetization orientation by a femtosecond pulse laser is an efficient way for advanced information storage technology. We report a comprehensive study of the interlayer coupling effect on the magnetization dynamics in [Ni/Co]4/Ru(tRu)/[Co/Ni]3 perpendicular magnetic films by the time-resolved magneto-optical Kerr effect approach. By controlling the antiferromagnetic (AF) interlayer coupling field Hex and external magnetic field H, we demonstrate distinctly different dynamic behaviors upon laser excitation. First, three kinds of demagnetization process, including nonchange, ultrafast increase, or decrease in Kerr signal, can occur within the short time delay of 2 ps. Second, in the relaxation process, in addition to the normal coherent precession, an additional out-of-phase mode is detected for the AF-coupled samples, whose amplitude and frequency depend also strongly on Hex and H. The H-dependent frequency curves of both modes are well interpreted with the deduced analytical express...