A metastable hard magnetic phase in the crystallization process of the Fe75Si11B10Nb3Sn1 alloy

A very interesting characteristic of FeSiB based amorphous alloys is its so ft magnetic behavior. Most of these alloys remains soft along the crystalli zation process up to the nucleation of the iron borides. Examples of this a re the widely studied Finemet and the FeSiBSn. In this work the crystalliza tion of Fe76Si11B10N3 and Fe75Si11B10Nb3Sn1 is studied by means of X-ray di ffraction, Mossbauer spectroscopy and coercive magnetic field measurements after one hour isothermal annealing at different temperatures. In the cryst allization process of the latter alloy a hard magnetic phase appeared when the samples were annealed above 773 K. The soft magnetic behavior was recov ered after annealing at 873 K. The hyperfine parameters as well as the X-ra y diffraction patterns are reported.