Influence of composition on hyperfine interactions in FeMoCuB nanocrystalline alloy
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Influence of varying Fe/B ratio upon hyperfine interactions is investigated in the Fe91−x Mo8Cu1Bx rapidly quenched alloys. They are studied both in the as-quenched (amorphous) state as well as after one-hour annealing at different temperatures ranging from 330 °C up to 650 °C. Such a heat treatment causes significant structural changes featuring a formation of nanocrystalline bcc-Fe grains during the first crystallization step. At higher annealing temperatures, a grain growth of bcc-Fe and occurrence of additional crystalline phases are observed. The relative fraction of the crystalline phase governs the development of magnetic hyperfine fields in the residual amorphous matrix even if this was fully paramagnetic in the as-quenched state. The development of hyperfine interactions is discussed as a function of annealing temperature and composition of the investigated alloys. 57Fe Mössbauer spectrometry was used as a principal analytical method. Additional information related to the structural arrangement is obtained from X-ray diffractometry. It is shown that in the as-quenched state, the relative fraction of magnetic hyperfine interactions increases as the amount of B rises. In partially crystalline samples, the contribution of magnetic hyperfine interactions inside the retained amorphous matrix increases with annealing temperature even though the relative fraction of amorphous magnetic regions decreases.
Key wordsnanocrystalline alloys microstructure Mössbauer spectrometry hyperfine interactions amorphous solids
- K. Suzuki, N. Kataoka, A. Inoue, A. Makino, and T. Masumoto: Mater. Trans. JIM 31 (1990) 743.Google Scholar
- M. Miglierini, J. Degmová, T. Kaňuch, P. Švec, E. Illeková, and D. Janičkovič: in Properties and Applications of Nanocrystalline Alloys from Amorphous Precursors (Ed. B. Idzikowski et al.). Kluwer Acad. Publ., 2005, p. 421.Google Scholar