Mossbauer study of nanocrystalline alloys

The current status of the Mossbauer investigations of the soft magnetic nan ocrystalline alloys produced by utilizing the first step of crystallization of the amorphous alloys such as FeCuNbSiB and FeZrBCu is reviewed. Convent ional Mossbauer measurements allow the identification of phases formed due to annealing of the amorphous precursor and the evaluation of their relativ e content. The unconventional rf-Mossbauer technique, in which the rf colla pse and sideband effects we employed, permits us to distinguish the magneti cally soft nanocrystalline bcc-Fe phase from the magnetically harder microc rystalline Fe. Qualitative information concerning the distribution of aniso tropy fields in the nanocrystalline grains can be inferred from the depende nce of the rf collapsed spectra on the rf field intensity. The rf-sidebands effect reveals strong reduction of magnetostriction due to the formation o f the nanocrystalline phase. The rf-Mossbauer technique provides a unique o pportunity to study the microstructure and magnetic properties of each phas e formed in the amorphous precursor.