Computer simulations for thin films of amorphous rare earth-transition metal alloys which are used for magneto-optical recording media are performed. In these simulations, the recording media are two dimensional lattice of 64×64 magnetic moments with lattice distance 10Å. The motion of the magnetic moments follows the dynamic equation of Landau-Lifshitz-Gilbert(LLG) under the influence of an effective field arising from the local anisotropy, nearest-neighbor exchange, classical dipole-dipole interaction, and an external applied field. According to the LLG equation, we have investigated the process of domain wall formation for a medium with random axis anisotropy δ_θ. For nonzero of δ_θ, it was found that 2π-Bloch wall line appear at the boundaries of magnetic domain and it is jagged. Finally, the effects of exchange stiffness coefficient A_x and anisotropy coefficient K_u on the wall width and the dispersion which represcnts jaggedness of domain wall are studied.
抄録全体を表示