CHAOTIC OSCILLATION OF DOMAIN-WALL IN NONEQUILIBRIUM STATE

The nonlinear equation of the Bloch wall notion is presented by the modification of Slonczewski equation based on Landau-Lifshitz-Gilbert equation. The nonlinear force of restitution caused by an internal stress and an eddy current damping are added. The computer simulation is performed using the fourth Runge-Kutta method. The amplitude of the domain wall oscillation in the frequency region from 50 kHz to 1 MHz is calculated and compared with the experimental values for CoZrMo/SiO2 multilayered core which are obtained by the image processing system. The experimentally observed decrease of amplitude with increasing frequency is reproduced well. The chaotic oscillation of a domain wall in an ideal potential well is shown to appear in spite of no randomness using the computer simulation. Another chaotic oscillation of the domain wall with the Barkhausen jumps from one potential to the neighbor is shown.