Vortex structure in magnetic nanodots: Dipolar interaction, mobile spin model, phase transition and melting

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:528

Article

Bailly-Reyre, Aurelien¹  Diep, H. T.² 

[1] Univ Paris, Sorbonne Univ, LPNHE Lab Phys Nucl & Hautes Energies, CNRS,IN2P3, 4 Pl Jussieu, F-75005 Paris, France

[2] Univ Cergy Pontoise, CY Cergy Paris Univ, Lab Phys Theor & Modelisat, CNRS,UMR 8089, 2 Ave Adolphe Chauvin, F-95302 Cergy Pontoise, France

关键词: Magnetic nanodots;    Dipolar interaction;    Vortex structure;    Mobile spin model;    Melting phase transition;   

DOI  :  10.1016/j.jmmm.2021.167813

来源: Elsevier

【 摘 要 】

We study in this article properties of a nanodot embedded in a support by Monte Carlo simulation. The nanodot is a piece of simple cubic lattice where each site is occupied by a mobile Heisenberg spin which can move from one lattice site to another under the effect of the temperature and its interaction with neighbors. We take into account a short-range exchange interaction between spins and a long-range dipolar interaction. We show that the ground-state configuration is a vortex around the dot central axis: the spins on the dot boundary lie in the xy plane but go out of plane with a net perpendicular magnetization at the dot center. Possible applications are discussed. Finite-temperature properties are studied. We show the characteristics of the surface melting and determine the energy, the diffusion coefficient and the layer magnetizations as functions of temperature.

【 授权许可】

Free