Thermal Stoner-Wohlfarth model for magnetodynamics of single domain nanoparticles

Autor(en)

Deniz Mostarac, Andrey A. Kuznetsov, Santiago Helbig, Claas Abert, Pedro A. Sánchez, Dieter Suess, Sofia S. Kantorovich

Abstrakt

We present the thermal Stoner-Wohlfarth (tSW) model and apply it in the context of molecular dynamics simulations. The model is validated against an ensemble of immobilized, randomly oriented uniaxial particles (solid superparamagnet) and a classical dilute ferrofluid for different combinations of anisotropy strength and magnetic field/moment coupling, at a fixed temperature. We compare analytical and simulation results to quantify the viability of the tSW model in reproducing the equilibrium properties (with and without dipole-dipole interactions) and dynamic properties (without dipole-dipole interactions) of magnetic soft matter systems. We show that if the anisotropy of a particle is more than five times higher than the thermal fluctuations, the tSW model is applicable and efficient. This approach allows one to consider the interplay between Néel and Brownian relaxation, often neglected in the fixed point-dipole representation-based magnetic soft matter theoretical investigations.

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie, Physik Funktioneller Materialien

Externe Organisation(en)

Università degli Studi di Roma La Sapienza, Delft University of Technology

Journal

Physical Review B

Band

111

Anzahl der Seiten

14

ISSN

2469-9950

DOI

https://doi.org/10.48550/arXiv.2408.06136

Publikationsdatum

01-2025

Peer-reviewed

Ja

ÖFOS 2012

103043 Computational Physics, 103015 Kondensierte Materie

ASJC Scopus Sachgebiete

Electronic, Optical and Magnetic Materials, Condensed Matter Physics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/e7233f47-48dd-4f7d-9424-2dd09b82dd8e