Micromagnetic Simulations Study of Skyrmions in Magnetic FePt Nanoelements

TL;DR

This study uses micromagnetic simulations to explore the formation and stability of skyrmions in FePt nanoelements, revealing that skyrmions can be generated without chiral interactions by tuning magnetocrystalline anisotropy.

Contribution

It demonstrates the creation of skyrmions in FePt nanoelements solely through variation of magnetocrystalline anisotropy, without the need for chiral interactions.

Findings

Skyrmions are formed in FePt nanoelements with specific anisotropy orientations.

Multiple skyrmions can coexist and persist under certain external fields.

Skyrmion number can be greater than one in these systems.

Abstract

The magnetization reversal in 330 nm triangular prismatic magnetic nanoelements with variable magnetocrystalline anisotropy similar to that of partially chemically ordered FePt is studied using micromagnetic simulations employing Finite Element discretizations. Several magnetic properties including the evaluation of the magnetic skyrmion number $S$ are computed in order to characterize magnetic configurations exhibiting vortex-like formations. Magnetic vortices and skyrmions are revealed in different systems generated by the variation of the magnitude and relative orientation of the magnetocrystalline anisotropy direction, with respect to the normal to the triangular prism base. Micromagnetic configurations with skyrmion number greater than one have been detected for the case where magnetocrystalline anisotropy was normal to nanoelement's base. For particular magnetocrystalline anisotropy values three distinct skyrmions are formed and persist for a range of external fields. The simulation-based calculations of the skyrmion number S revealed that skyrmions can be created for magnetic nanoparticle systems lacking of chiral interactions such as Dzyaloshinsky-Moriya, but by only varying the magnetocrystalline anisotropy.