Magnetic domain walls in constrained geometries

Abstract

Magnetic domain walls have been studied in micrometer-sized ${\mathrm{Fe}}_{20}{\mathrm{Ni}}_{80}$ elements containing geometrical constrictions by spin-polarized scanning electron microscopy and numerical simulations. By controlling the constriction dimensions, the wall width can be tailored and the wall type modified. In particular, the width of a ${180}^{\ifmmode^\circ\else\textdegree\fi{}}$ N\'eel wall can be strongly reduced or increased by the constriction geometry compared with the wall in unconstrained systems.