LONG-TIME RELAXATION OF AN ORDERED MAGNETIC-STRUCTURE

In a Mossbauer investigation of the parameters of the hyperfine intera ctions on Fe-57 nuclei in the ferromagnetic Tb0.8Y0.2Fe2, we have made the first observation of long-time (days, months) relaxation of an or dered magnetic structure. tn this effect the orientation of some momen ts in a sample changes under the action of a pulsed magnetic field (up to 250 kOe) and then slowly reverts to the initial state by means of gradual decomposition of clusters of the reoriented moments. A theoret ical estimate of the relaxation time is made. (C) 1998 American Instit ute of Physics.