Magnetic properties of FINEMET with excimer laser treated surface layers

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 producing 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 the total power loss. We found that surface defects in the form of relatively shallow grooves produced by the excimer laser treatment are not sufficient 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.