Domain Dynamics of Magnetic Films with Perpendicular Anisotropy

TL;DR

This paper investigates the magnetic behavior of nanoscale films with perpendicular anisotropy through experiments and simulations, revealing insights into domain wall dynamics and hysteresis mechanisms.

Contribution

It combines polarization microscopy and Monte Carlo simulations to analyze magnetization reversal and domain dynamics in magnetic films with perpendicular anisotropy.

Findings

Good qualitative agreement between experiments and simulations.

Hysteresis described as a thermally rounded depinning transition.

Temperature and field dependence of domain wall velocity elucidated.

Abstract

We study the magnetic properties of nanoscale magnetic films with large perpendicular anisotropy comparing polarization microscopy measurements on Co_28Pt_72 alloy samples based on the magneto-optical Kerr effect with Monte Carlo simulations of a corresponding micromagnetic model. We focus on the understanding of the dynamics especially the temperature and field dependence of the magnetisation reversal process. The experimental and simulational results for hysteresis, the reversal mechanism, domain configurations during the reversal, and the time dependence of the magnetisation are in very good qualitative agreement. The results for the field and temperature dependence of the domain wall velocity suggest that for thin films the hysteresis can be described as a depinning transition of the domain walls rounded by thermal activation for finite temperatures.