Change in the magnetic configurations of tubular nanostructures by tuning dipolar interactions

Abstract

We have investigated the equilibrium states of ferromagnetic single wall nanotubes by means of atomistic Monte Carlo simulations of a zig-zag lattice of Heisenberg spins on the surface of a cylinder. The main focus of our study is to determine how the competition between short-range exchange (J) and long-range dipolar (D) interactions influences the low temperature magnetic order of the nanotubes as well as the thermal-driven transitions involved. Apart from the uniform and vortex states occurring for dominant J or D, we find that helical states become stable for a range of intermediate values of g = D=J that depends on the radius and length of the nanotube. Introducing a vorticity order parameter to better characterize helical and vortex states, we find the pseudo-critical temperatures for the transitions between these states and we establish the magnetic phase diagrams of their stability regions as a function of the nanotube aspect ratio. Comparison of the energy of the states obtained by simulation with those of simpler theoretical structures that interpolate continuously between them, reveals a high degree of metastability of the helical structures that might be relevant for their reversal modes.

arXiv comment21 pages, 14 figures, SI avaliable from authors. Accepted in Scientific Reports 2018

References in corpus (9)

• Machine-learning assistant DFT study of half-metallic full-Heusler alloy N2CaNa: structural, electronic, mechanical, and thermodynamics properties
• Reversal mechanism of an individual Ni nanotube simultaneously studied by torque and SQUID magnetometry
• Scaling relations for magnetic nanoparticles
• Torsion induced effects in magnetic nanowires
• Imaging stray magnetic field of individual ferromagnetic nanotubes
• Imaging magnetic vortex configurations in ferromagnetic nanotubes
• Geometry induced phase transitions in magnetic spherical shell
• Observation of vortex-nucleated magnetization reversal in individual ferromagnetic nanotubes
• Monte Carlo study of magnetic nanoparticles adsorbed on halloysite $A{l}_{2}S{i}_2{O}_5(OH{)}_4$ nanotubes

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