Percolation and orientational ordering in systems of magnetic nanorods

TL;DR

This study uses Monte Carlo simulations to explore how magnetic nanorods form structures, showing unique behaviors like lowered percolation thresholds and tunable properties under magnetic fields, differing from non-magnetic or single-dipole rods.

Contribution

It introduces a model of magnetic nanorods with fused spheres and permanent dipoles, revealing new structural and percolation behaviors not seen in traditional rod systems.

Findings

Lower percolation threshold at low densities for magnetic nanorods

Stabilization of high-density nematic phase

Percolation threshold tunable by external magnetic field

Abstract

Based on Monte Carlo (MC) computer simulations we study the structure formation of a system of magnetic nanorods. Our model particles consist of fused spheres with permanent magnetic dipole moments, as inspired by recent experiments. The resulting system behaves significantly different from a system of hard (non-magnetic) rods or magnetic rods with a single longitudinal dipole. In particular, we observe for the magnetic nanorods a significant decrease of the percolation threshold (as compared to non-magnetic rods) at low densities, and a stabilization of the high-density nematic phase. Moreover, the percolation threshold is tunable by an external magnetic field.