Depth selective analysis of phases and spin textures in amorphous, nanocrystalline and crystalline ribbons treated with an excimer laser

Abstract

Iron-based amorphous alloys have attracted technological and scientific interest due to their soft magnetic properties. Recently it was found that amorphous alloys like Fe73.5Cu1Nb3Si13.5B9 undergo a transition to the nanocrystalline state after proper annealing, thus exhibiting excellent magnetic properties. Laser surface treatment of amorphous soft magnetic materials is known to have a strong influence on their spin texture. Laser treatment of crystalline alloys can induce changes in their phase structure, as for example the amorphization of surface layers. In this study, the authors report on the reaction of both Fe- and Co-based amorphous alloys as well as nanocrystalline and crystalline Fe73.5Cu1Nb3Si13.5B9 on excimer laser treatment. Simultaneous triple radiation Mossbauer spectroscopy (STRMS) is a powerful tool for the study of these phenomena. In order to estimate the depths of origin of the spectral information, simple analytical expressions for the depth profiles of the involved techniques are calculated.