The positive influence of laser treating on the decrease of power losses of
many soft magnetic materials (as well as nanocrystalline FINEMET) is well
known. The surface defects cause refinement of the domain structure produci
ng small domains with movable domain walls. Such a refinement is one of the
ways of reducing dynamic loss at higher frequencies which is dominant in t
he total power loss. We found that surface defects in the form of relativel
y shallow grooves produced by the excimer laser treatment are not sufficien
t to influence the bulk coercivity, but they do influence the surface-layer
coercivity and domain structure. (C) 1999 Elsevier Science B.V. All rights
reserved.