Micromagnetic calculation of the magnetization process in nanocontacts

We report herein the micromagnetic calculations of the magnetic domain walls in nanoconstrictions of various shapes for H-shaped samples and estimate the domain wall widths. The length and width of the nanoconstriction and the exchange stiffness constant in the nanoconstriction was varied for each case. In the case of a uniform exchange stiffness constant at the nanoconstriction, the domain wall width depends on the length and width of the nanoconstriction. Each domain wall width D calculated herein is longer than the constriction length L, and the exchange stiffness constant is 1.05×10−6erg∕cm. The small exchange stiffness at the nanoconstriction leads to the small domain wall width. These results imply the possibility of the large domain wall scattering only for nanoconstrictions with a small effective exchange coupling between the two magnetic materials.