On the transition between thermally activated and dynamic magnetic reversal of fine particles

IF 2.5 3区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY Journal of Magnetism and Magnetic Materials Pub Date : 2025-02-11 DOI:10.1016/j.jmmm.2025.172849

Andreas Lyberatos

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引用次数: 0

Abstract

A method of calculating exactly the switching time

t_{o}

of the magnetization of a uniaxially anisotropic single domain (SD) particle at the boundary between thermo-activated and damping-limited reversal is presented. The generalized free energy function of the system is used to deduce the intrinsic switching field marking the transition point and numerical integration of the stochastic Landau–Lifshitz–Gilbert (LLG) equation of motion is carried out to determine the switching statistics. We study the variation of

t_{o}

with the tilt angle of the applied field with respect to the easy axis, the grain size and damping. At the cross-over transition the barrierless reversal is driven by thermal perturbations and the switching time in the presence of an axial field varies as

t_{o} \propto \sqrt{K_{u} V / k_{B} T}

, where

K_{u}

is the first order anisotropy constant and

V

is the volume of the particle.

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来源期刊

Journal of Magnetism and Magnetic Materials 物理-材料科学：综合

CiteScore

5.30

自引率

11.10%

发文量

1149

审稿时长

59 days

期刊介绍： The Journal of Magnetism and Magnetic Materials provides an important forum for the disclosure and discussion of original contributions covering the whole spectrum of topics, from basic magnetism to the technology and applications of magnetic materials. The journal encourages greater interaction between the basic and applied sub-disciplines of magnetism with comprehensive review articles, in addition to full-length contributions. In addition, other categories of contributions are welcome, including Critical Focused issues, Current Perspectives and Outreach to the General Public. Main Categories: Full-length articles: Technically original research documents that report results of value to the communities that comprise the journal audience. The link between chemical, structural and microstructural properties on the one hand and magnetic properties on the other hand are encouraged. In addition to general topics covering all areas of magnetism and magnetic materials, the full-length articles also include three sub-sections, focusing on Nanomagnetism, Spintronics and Applications. The sub-section on Nanomagnetism contains articles on magnetic nanoparticles, nanowires, thin films, 2D materials and other nanoscale magnetic materials and their applications. The sub-section on Spintronics contains articles on magnetoresistance, magnetoimpedance, magneto-optical phenomena, Micro-Electro-Mechanical Systems (MEMS), and other topics related to spin current control and magneto-transport phenomena. The sub-section on Applications display papers that focus on applications of magnetic materials. The applications need to show a connection to magnetism. Review articles: Review articles organize, clarify, and summarize existing major works in the areas covered by the Journal and provide comprehensive citations to the full spectrum of relevant literature.