Nucleation of magnetic skyrmions on curvilinear surfaces using local magnetic fields

TL;DR

This study demonstrates that curvilinear magnetic films on spherical particles can host stable skyrmions, which can be written using local magnetic fields, advancing 3D magnetic data storage and logic applications.

Contribution

It shows that curvature influences skyrmion stability and enables controlled skyrmion creation on 3D surfaces using local magnetic fields.

Findings

Curvilinear films exhibit 3D spiraling stripe states unlike planar films.

Metastable skyrmions can be generated at the top of spherical particles.

Curvilinear surfaces provide a platform for skyrmion stabilization and manipulation.

Abstract

Magnetic skyrmions stabilized by interfacial Dzyaloshinskii-Moriya interactions (DMI) are promising candidates for applications in memory, logic, and neuromorphic computing. Beyond planar films, theoretical studies predict that curvature can influence skyrmion stability by introducing effective chiral interactions. Here, we investigate skyrmion formation on self-assembled polystyrene particles coated with Pt/Co/Ta multilayers by magnetron sputtering. Vibrating sample magnetometry reveals clear differences in the magnetic reversal behavior of the curvilinear film compared to that of the planar counterpart. Using non-invasive imaging methods such as scanning transmission X-ray microscopy and high-sensitivity in-vacuum magnetic force microscopy (MFM) with low moment magnetic tipcs, we observe a maze domain pattern for the planar films while the curvilinear film reveals three-dimensional spiraling stripe states. By employing a conventional MFM operating under ambient conditions requiring a tip with a higher magnetic moment, we demonstrate that these stripe states can rupture into metastable skyrmions located at the top of the spherical particles by applying consecutive scans. Our results demonstrate that curvilinear films offer an accessible platform for stabilizing single skyrmions using local magnetic field stimuli, opening pathways to study the interplay between interfacial and curvature-induced DMIs and enabling controlled skyrmion writing on three-dimensional magnetic architectures.