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type:Journal Article, The pinning characteristics of a 180 degrees domain wall with grooves are investigated using the micromagnetic simulation. The depinning fields required to pull the wall out of the grooved region were strongly related to the pinning characteristics at each step edge. The depinning field difference between the wall movement directions was improved by the increase of the lower depinning field compared to that with the steplike thickness change. It was also found that the depinning fields for various groove widths were almost constant and the wall displacement was further suppressed by the narrower groove having the vertical edge. (c) 2005 American Institute of Physics., source:http://dx.doi.org/10.1063/1.1857652, source:http://www.aip.org

type:Journal Article, The pinning characteristics of a domain wall with a step-like thickness change along the wall is investigated in 0.15- to 0.5-mum-thick films with an in-plane anisotropy using micromagnetic simulation based on the Landau-Lifshitz-Gilbert equation. The asymmetric Bloch wall having the structure in which the magnetostatic coupling develops between spins near the step when the wall is pinned shows the bi-directional pinning effect for magnetic fields applied along the magnetic domain. The wall energy of the pinned wall decreases with increasing step depth due to the largely decrease of the exchange energy component. The depinning field for the negative applied fields which drive the wall in the direction of the nongrooved region (thick film region) is considerably larger than that for the positive ones which drive the wall in the direction of the grooved region (thin film region). The depinning fields for both the positive and negative applied fields increase with decreasing film thickness.

type:Journal Article, Wall pinning effects with self-induced spatially varying uniaxial anisotropy in various thick films have been studied using micromagnetic simulation based on the Landau-Lifshitz-Gilbert equation. In the simulation, the discretization region is in the cross section normal to the film plane. It is clarified that the wall structure is strongly related to pinning characteristics. Depinning fields of the wall having a flux-closure asymmetric vortex (C-shaped wall) are different in the wall movement directions due to the asymmetric wall structure. On the other hand, depinning fields of the wall with two vortices (S-shaped wall) which have a symmetric structure do not depend on the wall movement direction. Depinning fields for the S-shaped wall are different from both depinning fields for the C-shaped wall. (C) 2003 American Institute of Physics., source:http://dx.doi.org/10.1063/1.1560703, source:http://www.aip.org