Coercivity Variation in Ni$_80$Fe$_20$Ferromagnetic Nanowires

Deep ultraviolet lithography was used to fabricate highly ordered 80-nm-thick Ni
$_80$
Fe
$_20$
nanowire arrays over a large area (4
$,times,$
4 mm
$^2$
). The magnetic properties of the wire array display a marked increase in both the coercivity and switching field due to magnetic shape anisotropy compared with the bulk film. The angular variation of the coercivity for nanowire arrays has been investigated in order to probe the magnetization reversal process. Our systematic study of the coercivity variation, which is also aided by theoretical modeling, reveals that the curling mode of rotation is the dominant reversal mechanism.