Ordering in rolled-up single-walled ferromagnetic nanomembranes

TL;DR

This paper investigates the magnetic domain structures in rolled-up ferromagnetic nanomembranes, combining analytical and numerical methods to understand how stress and initial conditions influence magnetization patterns.

Contribution

It provides a comprehensive analysis of magnetization ordering in nanomembranes, including new insights into stress-induced anisotropies and their effects on domain structures.

Findings

Identified basic types of periodic magnetic ordering.

Verified domain structures in Permalloy and cobalt nanotubes.

Showed the influence of stress and initial magnetization state on domain patterns.

Abstract

Magnetization of soft-ferromagnetic nano- and microtubes of nanometer-thin walls (a single-widening rolled-up nanomembranes) is theoretically studied using analytical and numerical approaches including different stress-induced anisotropies. Within the analytical study, we consider magnetostatic effects qualitatively, with an effective anisotropy, while they are fully treated in the micromagnetic simulations (limited to the tubes of submicrometer diameters however). Basic types of the periodic ordering have been established and their presence in nanotubes of polycrystalline Permalloy and cobalt has been verified within the simulations. The domain structure is basically determined by a material-deposition-induced helical stress or a cooling-induced axial stress via the volume magnetostriction while it is influenced by the distribution of magnetic charges as well. Also, it is dependent on the initial state of the magnetization process.