  We present the use of planar waveguides to produce neutron microbeams in
order to investigate magnetic micro-structures with a micrometric spatial
resolution. We report experimental results on such measurements on a polarized
neutron reflectometer using a nonmagnetic waveguide structure to probe an
amorphous magnetic microwire. The spin-resolved transmission of a neutron
microbeam through a microwire was studied. The one dimensional mapping of the
neutron precession across the wire was measured.
