Relaxation in magnetic nanostructures

Authors

Ralph Skomski, University of Nebraska-LincolnFollow
J. Zhou, University of Nebraska - Lincoln
David J. Sellmyer, University of Nebraska-LincolnFollow

Date of this Version

May 2005

Comments

Published by American Institute of Physics. J. Applied Physics 97, 10A702 (2005). ©2005 American Institute of Physics. Permission to use. http://jap.aip.org/jap/.

Abstract

The damping of magnetization processes in nanostructures is investigated by Fokker–Planck-type model calculations and quantum-mechanical considerations based on Fermi's golden rule. In the absence of energy barriers, the problem reduces to a magnetic diffusion equation with a particle-size-dependent diffusivity which is indirectly proportional to the relaxation-time parameter τ_o. For small particles, the relaxation time is proportional to the particle volume, but when the particle size reaches a few nanometers, it approaches a constant bulk value.