Physics – Condensed Matter – Statistical Mechanics
Scientific paper
1999-08-10
Physics
Condensed Matter
Statistical Mechanics
8 pages, Revtex, 8 Figures included
Scientific paper
With decreasing particle size, different mechanisms dominate the thermally activated magnetization reversal in ferromagnetic particles. We investigate some of these mechanisms for the case of elongated, single-domain nanoparticles which we describe by a classical Heisenberg spin chain driven by an external magnetic field. For sufficiently small system size the magnetic moments rotate coherently. With increasing size a crossover to a reversal due to soliton-antisoliton nucleation sets in. For even larger systems many of these soliton-antisoliton pairs nucleate at the same time. These effects give rise to a complex size dependence of the energy barriers and characteristic time scales of the relaxation. We study these quantities using Monte Carlo simulations as well as a direct integration of the Landau-Lifshitz-Gilbert equation of motion with Langevin dynamics and we compare our results with asymptotic solutions for the escape rate following from the Fokker-Planck equation. Also, we investigate the crossover from coherent rotation to soliton-antisoliton nucleation and multi-droplet nucleation, especially its dependence on the system size, the external field and the anisotropy of the system.
Hinzke D.
Nowak Ulrich
No associations
LandOfFree
Magnetic relaxation in a classical spin chain as model for nanowires does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Magnetic relaxation in a classical spin chain as model for nanowires, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic relaxation in a classical spin chain as model for nanowires will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-201578