Interacting amorphous ferromagnetic wires: A complex system

Magnetization reversal of high and positive magnetostriction amorphous wire s gives rise to a square hysteresis loop owing to their particular domain s tructure. When two quasi-identical wires are placed close together, the lac k of simultaneous magnetization reversal produces a temporal instability in the hysteresis loop as a consequence of the magnetostatic interaction betw een them. This instability, having chaotic properties, is controlled by the amplitude and frequency of the applied magnetic field and depends on the l ength of the wires and distance between them. A theoretical model, based on an iterative algorithm, has been developed in order to understand the prop erties of the whole magnetization. The instability seems to originate in an irreversible rearrangement of the closure domain structure at the ends of the wires after each magnetization reversal. The magnetization of the set o f wires follows a potential law that can be explained in the framework of t he self-organized criticality, a theory of the complexity. (C) 1999 America n Institute of Physics. [S0021-8979(99)02705-X].