Monte Carlo simulations of $\mathrm{NiF}{\mathrm{e}}_2{\mathrm{O}}_4$ Nanoparticles

Abstract

We use Monte Carlo simulations to study $\mathrm{NiF}{\mathrm{e}}_2{\mathrm{O}}_4$ nanoparticles. Finite size and surface effects differentiate them from their bulk counterparts. A continuous version of the Wang-Landau algorithm is used to calculate the joint density of states $g(M_z,E)$ efficiently. From $g(M_z,E)$, we obtain the Bragg-Williams free energy of the particle, and other physical quantities. The hysteresis is observed when the nanoparticles have both surface disorder and surface anisotropy. We found that the finite coercivity is the result of interplay between surface disorder and surface anisotropy. If the surface disorder is absent or the surface anisotropy is relatively weak, the nanoparticles often exhibit superparamagnetism.

Written for 50th MMM Conference, to be published in J. Appl. Phys

References in corpus (4)

• An efficient, multiple range random walk algorithm to calculate the density of states
• Determining the density of states for classical statistical models: A random walk algorithm to produce a flat histogram
• Canonical local algorithms for spin systems: Heat Bath and Hasting's methods
• Exchange anisotropy, disorder and frustration in diluted, predominantly ferromagnetic, Heisenberg spin systems

Cited by in corpus (3)

• Sampling the two-dimensional density of states g(E,M) of a giant magnetic molecule using the Wang-Landau method
• A model for vortex formation in magnetic nanodots
• Relaxation of Ferroelectric States in 2D Distributions of quantum Dots:EELS Simulation