Memorizing of acoustic signal by magnetic structure of polycrystalline magnetics

A theoretical model of the phenomenon of memorizing an acoustic signal pass ing through polycrystalline magnetic media under the action of an rf magnet ic field of the same frequency is proposed. It has been shown that a space- periodic magnetic structure is formed because different conditions of irrev ersible change of magnetization take place in various points of the specime n due to the simultaneous action of acoustic and magnetic waves. The comput ation of the magnetic structures formed has been done. The influence of ani sotropy and magnetization inhomogeneity as well as that of the interaction between the magnetic grains has been discussed. (C) 1999 Elsevier Science B .V. All rights reserved.