Stochastic magnetization dynamics in single domain particles

Abstract

Magnetic particles are largely utilized in several applications ranging from magnetorheological fluids to bioscience and from nanothechnology to memories or logic devices. The behavior of each single particle at finite temperature (under thermal stochastic fluctuations) plays a central role in determining the response of the whole physical system taken into consideration. Here, the magnetization evolution is studied through the Landau-Lifshitz-Gilbert formalism and the non-equilibrium statistical mechanics is introduced with the Langevin and Fokker-Planck methodologies. As result of the combination of such techniques we analyse the stochastic magnetization dynamics and we numerically determine the convergence time, measuring the velocity of attainment of thermodynamic equilibrium, as function of the system temperature.

Improved efficiency of heat generation in nonlinear dynamics of magnetic nanoparticles

“…[15,21]. Accordingly, the enhancement effect shown in this work is 100%-15% (in case of a smaller damping the enhancement is larger).…”

“…[21] for H a = 0.2 × 10 5 A/m and M s = 10 5 A/m). In this case the nanoparticle has a single precession mode.…”

“…Giordano et al [21] treated the shape anisotropy of the isotropic ellipsoidal particles using a different notation, where L is the parameter giving the deviation from spherical symmetry. The link to our parameters is H a = (3L − 1)m S .…”

Stress-mediated magnetoelectric control of ferromagnetic domain wall position in multiferroic heterostructures

“…For comparison, we can cite the energy dissipation DE ¼ 10 4 fJ for one logic operation in a currentdriven gate based on the domain wall motion. 39 Further investigations on this subject will consist in analyzing the dynamic behavior, 31 the effects of thermal noise, 40 and the response of a real prototype.…”

Statistical mechanics of holonomic systems as a Brownian motion on smooth manifolds

“…Another important application is given by the dynamics of the magnetization vector in ferromagnetic particles. The classical Landau-Lifshitz-Gilbert equation [41,42], generalized by adding a noise term representing the magnetic fluctuations [43][44][45][46], leads to stochastic models of the magnetization dynamics [21,[47][48][49].…”