Thermally Activated Reversal in Magnetic Nanostructures
Thermally Activated Reversal in Magnetic Nanostructures
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DOI：
10.1142/9789812811578_0002
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
U. Nowak
中科院分区：
文献类型：
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作者：
U. Nowak
磁性结构的小型化对于基础研究和技术应用都具有重要意义。新的实验技术允许制备和研究空间扩展越来越小的磁系统。这导致了对小磁性颗粒和结构的行为的理解的兴趣增加到纳米尺度。随着磁性颗粒尺寸的减小，热活化变得相关。因此，了解有限温度对铁磁粒子的动力学行为和磁稳定性的作用是微磁学中的一个现代课题。这是有趣的，从一个基本的观点，以及对磁性器件的应用发展。这篇综述的目的是对磁系统中热活化的数值方法进行概述，只要它们可以用经典的自旋系统来描述。在这里，所建立的方法要么是Langevin动力学的Landau-Lifshitz-Gilbert方程的数值解，要么是Monte Carlo模拟。特别强调这两种方法之间的关系，以及根据实际时间间隔量化蒙特卡罗程序步骤的可能性。
The miniaturization of magnetic structures plays an important role for fundamental research as well as for technical applications. New experimental techniques allow for a preparation and investigation of magnetic systems of smaller and smaller spatial extension. This leads to an incremental interest in the understanding of the behavior of small magnetic particles and structures down to the nanometer scale. With decreasing size of magnetic particles thermal activation becomes relevant. The understanding of the role of a finite temperature for the dynamical behavior and magnetic stability of ferromagnetic particles is hence a modern subject in micromagnetism. It is interesting from a fundamental point of view as well as for the application development of magnetic devices. The goal of this review is to give an overview on numerical approaches to thermal activation in magnetic systems as far as they can be described by classical spin systems. Here, the established methods are either a numerical solution of the Landau-Lifshitz-Gilbert equation with Langevin dynamics or Monte Carlo simulations. Special emphasis is put on the relation between these two methods and on the possibility to quantify the steps of a Monte Carlo procedure in terms of realistic time intervals.