  We have measured the contribution of magnetic domain walls (DWs) to the
electric resistance in epitaxial manganite films patterned by electron-beam
lithography into a track containing a set of notches. We find a DW
resistance-area (RA) product of ~2.5 10^(-13) Ohm/m^2 at low temperature and
bias, which is several orders of magnitude larger than the values reported for
3d ferromagnets. However, the current-voltage characteristics are highly linear
which indicates that the DWs are not phase separated but metallic. The DWRA is
found to increase upon increasing the injected current, presumably reflecting
some deformation of the wall by spin-transfer. When increasing temperature, the
DWRA vanishes at ~225K which is likely related to the temperature dependence of
the film anisotropy.
