Dependence of Transverse Domain Wall Dynamics on Permalloy Nanowire Dimensions

Micromagnetic modeling was used to investigate transverse domain wall propagation through Permalloy nanowires of width,
w
, between 10 and 120 nm and thickness,
T
, between 2 and 20 nm. The transverse wall mobility below Walker breakdown, ¿, and Walker breakdown field,
H

_w
, depended on the exact wire dimensions, rather than simply a function of w/
T
, as suggested by 1-D analytical modeling. Empirical equations describing the
w
and
T
dependence of ¿ and
H

_w
were found from the micromagnetic data. As the model makes no assumptions about magnetization uniformity, these equations provide a generic description of ¿ and
H

_w
for transverse domain walls in Ni
₈₀
Fe
₂₀
nanowires.