Magnetic properties of clusters of supracolloidal magnetic polymers with central attraction

TL;DR

This study uses Langevin dynamics simulations to explore how different topologies of supracolloidal magnetic polymers influence their magnetic properties, revealing that central attraction significantly reduces susceptibility, especially in chain-like structures.

Contribution

It provides new insights into how SMP topology and central attraction affect magnetic susceptibility and internal magnetic structures in clusters.

Findings

Central attraction decreases suspension susceptibility across all SMP topologies.

Chain-like SMPs exhibit the largest susceptibility decrease due to vortex formation.

Topology influences the internal magnetic reorganization within clusters.

Abstract

Supracolloidal magnetic polymers (SMPs) are structures made by crosslinking magnetic particles. In this work, using Langevin dynamics simulations, we study the zero-field magnetic properties of clusters formed in suspensions of SMPs with different topologies -- chains, rings, X and Y -- that interact via Stockmayer potential. We find that the presence of central attraction, resulting in the formation of large compact clusters, leads to a dramatic decrease of the suspension initial susceptibility, independently from SMP topology. However, the largest decrease corresponds to chain-like SMPs with strongly interacting particles. This is due to the higher rotational degrees of freedom of SMPs with such topology, which allows the particles to reorganise themselves inside the clusters in such a way that their magnetic moments form energetically advantageous vortex structures with negligible net magnetic moments.