We report longitudinal Kerr hysteresis loops of the two surfaces of a
Fe80B20 amorphous melt-spun ribbon. We observe different magnetic prop
erties on the two sides. The results could be explained as being due t
o the presence of surface inhomogeneities having particular shapes, wh
ich induces high anisotropy, and to the bulk underlying magnetic domai
n structure which strongly interacts with the surface.