Micromagnetics of magnetization switching in nanostructured multilayer

Spin valve strips of NiFe/Co/Cu/Co with various pattern widths of sub-μm order were fabricated with a lithographic technique to study the size effect of the magnetization reversal. The longitudinal reversal process along the strip was examined in external fields ranging from 20 to 60 Oe, indicating that the reverse field increases with a decrease of pattern width. Micromagnetic simulations demonstrated that the longitudinal reversal at relatively low field can be associated with lateral expansion of the nucleated micro-domain.