Interfacial effect on the reverse of magnetization and ultrafast demagnetization in Co/Ni bilayers with perpendicular magnetic anisotropy
Interfacial effect on the reverse of magnetization and ultrafast demagnetization in Co/Ni bilayers with perpendicular magnetic anisotropy
复制标题
垂直磁各向异性 Co/Ni 双层中的界面效应对磁化反转和超快退磁的影响
DOI：
10.1088/1674-1056/27/5/057501
复制
发表时间：
2018
影响因子：
1.7
通讯作者：
Cheng Zhao-Hua
中科院分区：
文献类型：
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作者：
Gong Zi-Zhao;Zhang Wei;He Wei;Zhang Xiang-Qun;Liu Yong;Cheng Zhao-Hua
对于Co/Ni双层膜的静态磁性，宏观磁滞回线和微观磁矩分布已被确定的面向对象的微磁性框架（OOMMF）。研究发现，当双层系统完全解耦时，两相的磁化强度分别反转。随着界面交换耦合的增加，双层膜的介电常数急剧下降到一个谷值，然后缓慢上升到一个平台。另一方面，我们对Co/Ni双层膜的激光诱导超快退磁进行了原子论模拟。阻尼常数越大，退磁越快，退磁程度也越大，这与第一性原理的理论结果一致。对于磁化恢复过程，阻尼常数具有不同的峰值电子温度的恢复时间的影响，这是被忽略在以前的原子模拟，以及Landau-Liftshit-Bloch（LLB）微磁计算。此外，随着界面交换耦合的增加，Co和Ni的超快退磁曲线趋于一致，这是由两相现象向单相现象转变的一种表现。
For static magnetic properties of the Co/Ni bilayers, macroscopic hysteresis loops and microscopic magnetic moment distributions have been determined by the object oriented micromagnetic framework (OOMMF). It is found that when the bilayer systems are fully decoupled, the magnetizations of the two phases reverse separately. The coercivity of the bilayers decreases to a valley value sharply with increasing interfacial exchange coupling and then rises slowly to a platform. On the other hand, we have carried out an atomistic simulation for the laser-induced ultrafast demagnetization of the Co/Ni bilayer. A larger damping constant leads to a faster demagnetization as well as a larger degree of demagnetization, which is consistent with the first-principle theoretical results. For the magnetization recovery process, the damping constant has different influences on the recovery time with various peak electron temperatures, which is ignored in previous atomistic simulations as well as the Landau–Liftshit–Bloch (LLB) micromagnetic calculations. Furthermore, as the interfacial exchange coupling increases, the ultrafast demagnetization curves for Co and Ni become coincident, which is a demonstration for the transition from two-phase phenomenon to single-phase phenomenon.
DOI：
10.1002/https://dx..org/10.6028/nist.ir.6376
发表时间：
1999-09
期刊：
--
影响因子：
--
作者：
M. Donahue;D. G. Porter
通讯作者：
M. Donahue;D. G. Porter