Rotational properties of ferromagnetic nanoparticles driven by a precessing magnetic field in a viscous fluid

TL;DR

This paper investigates the rotational behavior of ferromagnetic nanoparticles in a precessing magnetic field within a viscous fluid, analyzing both deterministic and stochastic effects using Langevin and Fokker-Planck equations.

Contribution

It provides a comprehensive analytical and numerical study of nanoparticle rotation and magnetization dynamics under complex magnetic field conditions, including thermal fluctuations.

Findings

Analytical expressions for average precession frequency and magnetization.

Numerical validation of theoretical predictions.

Insights into thermal fluctuation effects on nanoparticle dynamics.

Abstract

We study the deterministic and stochastic rotational dynamics of ferromagnetic nanoparticles in a precessing magnetic field. Our approach is based on the system of effective Langevin equations and on the corresponding Fokker-Planck equation. Two key characteristics of the rotational dynamics, the average angular frequency of precession of nanoparticles and their average magnetization, are of our interest. Using the Langevin and Fokker-Planck equations, we calculate both analytically and numerically these characteristics in the deterministic and stochastic cases, determine their dependence on the model parameters, and analyze in detail the role of thermal fluctuations.