Mössbauer Study of Nanocrystalline Alloys |
M. Kopcewicz Institute of Electronic Materials Technology, Wólczyńska 133, 01-919 Warszawa, Poland |
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The current status of the Mössbauer investigations of the soft magnetic nanocrystalline alloys produced by utilizing the first step of crystallization of the amorphous alloys such as FeCuNbSiB and FeZrBCu is reviewed. Conventional Mössbauer measurements allow the identification of phases formed due to annealing of the amorphous precursor and the evaluation of their relative content. The unconventional rf-Mössbauer technique, in which the rf collapse and sideband effects are employed, permits us to distinguish the magnetically soft nanocrystalline bcc-Fe phase from the magnetically harder microcrystalline Fe. Qualitative information concerning the distribution of anisotropy fields in the nanocrystalline grains can be inferred from the dependence of the rf collapsed spectra on the rf field intensity. The rf-sidebands effect reveals strong reduction of magnetostriction due to the formation of the nanocrystalline phase. The rf-Mössbauer technique provides a unique opportunity to study the microstructure and magnetic properties of each phase formed in the amorphous precursor. |
DOI: 10.12693/APhysPolA.96.49 PACS numbers: 76.80.+y, 75.50.Kj, 75.50.Bb, 81.40.-z |