A platform for nanomagnetism - assembled ferromagnetic and antiferromagnetic dipolar tubes

TL;DR

This paper introduces a novel platform of dipolar sphere-assembled tubes that exhibit magnetic behaviors similar to nanotubes, including various magnetization states and antiferromagnetic phases, bridging mesoscopic and nanoscale magnetism.

Contribution

It demonstrates that dipolar sphere assemblies can replicate key magnetic phenomena of nanotubes, revealing new insights into mesoscopic magnetic systems.

Findings

Tube magnetization switches from circular to axial with length.

Reproduction of nanotube-like magnetostatic properties.

Identification of antiferromagnetic and vortex states.

Abstract

We report an interesting case where magnetic phenomena can transcend mesoscopic scales. Our system consists of tubes created by assembly of dipolar spheres. The cylindrical topology results in the breakup of degeneracy observed in the planar square and triangular packings. As far as the ground state is concerned, tubes switch from circular to axial magnetization with increasing tube length. All magnetostatic properties found in magnetic nanotubes, in which the dipolar interaction is comparable or dominate over the exchange interaction, are reproduced by the dipolar tubes including an intermediary helically magnetized state. Besides, we discuss antiferromagnetic phases and an interesting intermediary vortex state resulting from the square arrangement of the dipolar spheres.