CHAOTIC DYNAMICS OF INTERACTING DOMAIN-WALLS IN UNIAXIAL FERROMAGNETIC-FILMS

The nonlinear dynamics of a periodic system of interacting domain wall s in a thin ferromagnetic uniaxial film with transverse anisotropy is examined. The interaction between the domain walls takes place through the magnetostatic demagnifying fields of the domains. The equations o f motion derived for such a system of walls are solved numerically by a 4-5th-order Runge-Kutta scheme, while the uniformity of the distribu tions of the phase trajectory, the form of the Poincare cross section, and the spectral density of the vibrations serve as indicators of the type of oscillations. All the known types of oscillations are observe d in a computer simulation of this nonlinear system: periodic, quasipe riodic, and chaotic. The computational results have a universal charac ter for uniaxial, highly-anisotropic ferromagnetic films having a stri p domain structure, since the results can be easily scaled for materia ls with different magnetic characteristics. (C) 1997 American Institut e of Physics.