Magnetic phase diagram of interacting nanoparticle systems under the mean field model

TL;DR

This study explores the magnetic phase diagram of disordered nanoparticle systems with competing interactions using Monte Carlo simulations and mean field theory, identifying phases like superspin glass and superferromagnetic.

Contribution

It introduces a mean field-based phase diagram for nanoparticle systems with competing interactions, highlighting the boundary between different magnetic phases.

Findings

Identification of superspin glass and superferromagnetic phases

The phase boundary is determined by the Curie-Weiss temperature TCW=0

Magnetic behaviors depend on the interplay of interactions

Abstract

The disordered random-anisotropy magnetic nanoparticle systems with competing dipolar interactions and ferromagnetic exchange couplings are investigated by Monte Carlo simulations. Superspin glass (SSG) and superferromagnetic (SFM) behaviors are found at low temperatures depending on the interactions. Based on the mean field approximation, the Curie-Weiss temperature TCW = 0 is suggested as the phase boundary between the SSG systems and the SFM systems, which is convinced by the spontaneous magnetizations and relaxations. The magnetic phase diagram is plotted.