ICAME 2007

Disordered nature of structural arrangement in amorphous and nanocrystalline alloys gives rise to advantageous soft magnetic properties in particular from a practical application viewpoint [1]. Especially nanocrystalline alloys attract a lot of scienti? c interest because, contrary to their amorphous counterparts, their magnetic parameters do not substantially deteriorate at elevated temperatures during the process of their practical exploitation. To bene? t from their unique magnetic pr- erties, the mechanism of crystallization should be known. Here, we present the study of structural transformation of NANOPERM-type alloys by the help of Mössbauer spectrometry, conventional X-ray diffraction (XRD), and by an advanced diffraction of synchrotron radiation. 2 Experimental Alloys of the composition Fe Mo Cu B for x = 12, 15, 17, 20 prepared by 91? x 8 1 x 57 rapid quenching on a rotating wheel were analyzed in the as-cast state by Fe transmission Mössbauer spectrometry (TMS) and by conversion electron Mössbauer spectrometry (CEMS). The obtained as-quenched ribbons were about 10 mm wide and 20 ? m thick. The nanocrystalline state was achieved by annealing about 2 cm ? long samples for 1 h at temperatures up to 650 C in a vacuum. Conventional XRD was performed with Cu-K radiation in Bragg-Brentano con? guration with graphite ? monochromator in the diffracted beam. Monochromatic synchrotron radiation of 7keV(? = 0. 178 nm) provided at the KMC-2 beamline at BESSY Berlin was used for in situ examinations of structural transformations during continuous heat treatment.