We show that equilibrium geometrically constrained domain patterns are two- or three-dimensional magnetic configurations localized around sharp constrictions. Their typical size w depends on both the length d and cross size a of the constriction. When $d<\mathrm{}{L}_0$ the value $w\simeq \min \left[{\mathrm{}(2a+d),L}_0\right],$ where $L_0$ is the conventional wall width. The localized structures undergo small deformation under magnetic fields and at a threshold field they detach from the constriction and magnetization reversal occurs.

• Received 17 December 2001

DOI:https://doi.org/10.1103/PhysRevB.65.184425