Thermal fluctuations of fine magnetic particles
Institut Laue-Langevin - Avenue des Martyrs BP 156, 38042 Grenoble Cedex 09, France
Accepted: 5 August 1998
We study the influence of thermal fluctuations on the dynamics of a fine magnetic particle in a uniaxial potential. At low temperature, the transverse component of the magnetization precesses coherently about the easy axis. With rising T, thermal fluctuations reduce the precession frequency and, as the thermal energy approaches the anisotropy potential, they drive a crossover to incoherent motion. Our findings agree with recent neutron scattering data.
PACS: 75.50.Tt – Fine-particle systems / 75.40.Gb – Dynamic properties (dynamic susceptibility, spin waves, spin diffusion, dynamic scaling, etc.) / 33.35.+r – Electron resonance and relaxation
© EDP Sciences, 1998