METHOD OF MAGNETIC DOMAIN MODELING ON A MOVING MAGNETOOPTICAL DISK

A method is proposed to simulate the formation process and the shape o f a magnetic domain on a moving magneto-optical disk. It is assumed th at the direction of the force acting on the domain wall is perpendicul ar to the isothermal line of the critical temperature. Slicing lines p erpendicular are taken at regular intervals to this isotherm, and by a pplying the one-dimensional bubble model the wall position on each sli cing line is determined. Connecting the wall positions in each time fr ame the evolution of the domain shape in the formation process is obta ined. By applying this method to Tb23Fe77 thin film, it is found that the domain wall in Tb23Fe77 thin film on a moving disk was first pinne d in the cooling region which was the leading region of laser exposure on the disk, then the pinned wall expanded toward the heating region, and a closed domain was formed after the laser was turned off.