MICROMAGNETIC ANALYSIS OF S=1 MAGNETIC-BUBBLES WITH CURVATURE EFFECTS

The micromagnetic model of Della Torre et al. [7] has been extended to include the analysis of bubble collapse and runout and to reduce computation times by making radius corrections. Results were obtained for a range of bubble aspect ratios and quantities describing wall bulging, flaring, and twisting were computed. Data on material parameter effects is also presented. Magnetization orientation angle contour maps over the r-z plane in the wall region are presented. Wall structure was found to depend strongly on bubble aspect ratio as well as on material parameters. Wall bulging increases with decreasing bubble aspect ratio; at Q=2.3, it is about 5% of the bubble radius near collapse, and 1.5% near runout. The wall thickness at the film center is characteristic of a Bloch wall, but near the surface, azimuthal twisting and wall width flaring increase with bubble aspect ratio. Calculated wall area energy densities are lower than those of corresponding wall structures of variational models. For Q=2.3, it was found that the range of bubble stability is smaller than in previous predictions.