Molecular dynamics simulations of the dipolar-induced formation of magnetic nanochains and nanorings

TL;DR

This study uses molecular dynamics simulations to explore how magnetic nanoparticles form chains and rings due to dipolar interactions, analyzing the effects of temperature and magnetic fields on their arrangements.

Contribution

It provides a detailed analysis of the dynamics and thermodynamics of magnetic nanoparticle self-assembly, highlighting the influence of external conditions on structure formation.

Findings

Phase diagrams explained by energetic considerations

Temperature and magnetic fields significantly affect nanoparticle arrangements

Formation of chains and rings observed in simulations

Abstract

Iron, cobalt and nickel nanoparticles, grown in the gas phase, are known to arrange in chains and bracelet-like rings due to the long-range dipolar interaction between the ferromagnetic (or super-paramagnetic) particles. We investigate the dynamics and thermodynamics of such magnetic dipolar nanoparticles for low densities using molecular dynamics simulations and analyze the influence of temperature and external magnetic fields on two- and three-dimensional systems. The obtained phase diagrams can be understood by using simple energetic arguments.