Self-consistent solution of magnetic and friction energy losses of a magnetic nanoparticle

Author(s)
Santiago Helbig, Claas Abert, Pedro A. Sánchez, Sofia S. Kantorovich, Dieter Suess
Abstract

We present a simple simulation model for analyzing magnetic and frictional losses of magnetic nanoparticles in viscous fluids subject to alternating magnetic fields. Assuming a particle size below the single-domain limit, we use a macrospin approach and solve the Landau-Lifshitz-Gilbert equation coupled to the mechanical torque equation. Despite its simplicity the presented model exhibits surprisingly rich physics and enables a detailed analysis of the different loss processes depending on field parameters and initial arrangement of the particle and the field. Depending on those parameters regions of different steady states emerge: a region with dominating magnetic relaxation and high magnetic losses and another region region with high frictional losses at low fields or low frequencies. The energy increases continuously even across regime boundaries up to frequencies above the viscous relaxation limit. At those higher frequencies the steady state can also depend on the initial orientation of the particle in the external field. The general behavior and special cases and their specific absorption rates are compared and discussed.

Organisation(s)
Computational and Soft Matter Physics, Physics of Functional Materials, Research Platform MMM Mathematics-Magnetism-Materials
External organisation(s)
University of the Balearic Islands, Ural Federal University
Journal
Physical Review B
Volume
107
No. of pages
11
ISSN
2469-9950
DOI
https://doi.org/10.1103/PhysRevB.107.054416
Publication date
05-2022
Peer reviewed
Yes
Austrian Fields of Science 2012
103017 Magnetism
Keywords
ASJC Scopus subject areas
Electronic, Optical and Magnetic Materials, Condensed Matter Physics
Portal url
https://ucrisportal.univie.ac.at/en/publications/4f3a24bf-af44-49f5-8aed-bbc1c6f8eb39