SLOW MAGNETIC-RELAXATION IN IRON - A FERROMAGNETIC LIQUID

The remanent magnetization of single-crystal iron whiskers has been me asured from 10(-5) to 10(4) seconds after the removal of an applied fi eld. The observed response is accurately modeled by localized magnon r elaxation on a Gaussian size distribution of dynamically correlated do mains, virtually identical to the distribution of excitations in glass -forming liquids. When fields of less than 1 oersted are removed, some relaxation occurs before 10(-5) second has elapsed; but when larger f ields are removed, essentially all of the response can be accounted fo r by magnon relaxation over the available time window. The model provi des a physical picture for the mechanism and observed distribution of Landau-Lifshitz damping parameters.