  This work is focused on determining the electrical resistance, which induced
by single domain wall in magnetic nanowire with a negligible defect. The
provided model covers a wide range of nanowire's diameters. The obtained result
demonstrates a few orders rapid reduction of the domain wall resistance
accompanied by its possible deviations versus the diameter growth ranging from
1.2 nm to 15.2 nm. The origin of these deviations, which are also identified as
oscillations, is referred to the non-uniform electron scattering on the domain
wall due to the intermixing electron scattering conditions: ballistic for one
spin channel and quasi-ballistic for other one with opposite spin direction. It
may happen when the domain wall width by value is approximately in between two
lengths: a mean free path with the spin down and spin up. The indirect evidence
of this finding is also coming from the fact that homogeneous nanowires shows
the most valuable domain wall resistance oscillations by magnitude rather than
segmented magnetic nanowires. In addition to the approach, where DW width is
constant, the other reasonable model is used when the domain wall can be
constrained for some conditions. The same results are valid for magnetic
junctions with domain wall. Finally, resistance simulation in the diffusive
range, when a diameter of the nanowire (or point-like junction) is larger than
any of spin resolved mean free path of electrons, successfully follows
experimental data for the single and double domain wall resistances available
in literature.
