Magnetization reversal in ultrashort magnetic field pulses
Magnetization reversal in ultrashort magnetic field pulses
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DOI：
10.1016/s0304-8853(00)00400-5
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发表时间：
2000-08
影响因子：
2.7
通讯作者：
M. Bauer;R. Lopusník;J. Fassbender;B. Hillebrands
中科院分区：
文献类型：
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作者：
M. Bauer;R. Lopusník;J. Fassbender;B. Hillebrands
我们报告了通过数值研究获得的磁性薄膜在超短横向局部磁场脉冲作用下的开关特性。薄膜中的磁化强度分布是在网格上计算的，假设网格正方形尺寸内有类似斯通纳的相干旋转。由于 4ps 磁场脉冲，垂直和面内磁化薄膜表现出磁化反转。在中心区域之外，脉冲持续时间比进动周期短。在此区域中，场脉冲期间磁化强度的演变并不强烈依赖于磁阻尼和/或脉冲形状。然而，最终的磁化强度分布受磁阻尼的影响。虽然脉冲持续时间与进动周期相比较短，但磁化弛豫到平衡状态所需的时间相当长。不同磁各向异性贡献和磁阻尼参数的影响进入磁化反转过程。将垂直各向异性与不同类型的面内各向异性的情况进行比较，由于形状各向异性相对于所讨论的各向异性的对称性，发现了主要差异。
We report the switching properties of a thin magnetic film subject to an ultrashort, laterally localized magnetic field pulse, obtained by numerical investigations. The magnetization distribution in the film is calculated on a grid assuming Stoner-like coherent rotation within the grid square size. Perpendicularly and in-plane magnetized films exhibit a magnetization reversal due to a 4ps magnetic field pulse. Outside the central region the pulse duration is short compared to the precession period. In this area the evolution of the magnetization during the field pulse does not depend strongly on magnetic damping and/or pulse shape. However, the final magnetization distribution is affected by the magnetic damping. Although the pulse duration is short compared to the precession period, the time needed for the relaxation of the magnetization to the equilibrium state is rather large. The influence of the different magnetic anisotropy contributions and the magnetic damping parameter enters into the magnetization reversal process. Comparing the case of perpendicular anisotropy with different kinds of in-plane anisotropies, a principal difference is found due to the symmetry of the shape anisotropy with respect to the anisotropy in question.