Crystallization behaviour of Fe40Ni40SixP20 − x (x=6, 10, 14) amorphous alloys

The progress in crystallization has been examined for three amorphous alloys produced by melt spinning (Fe40Ni40SixP20 − x with x=6, 10 and 14) by use of X-ray diffraction (XRD), transmission Mössbauer spectroscopy (TMS) and differential scanning calorimetry (DSC). Two main crystallization peaks are observed calorimetrically on heating. Analysis of the crystallization products reveals the formation of Ni-rich silicides and Fe(Si) bcc phases in the early stages and subsequent formation of Fe-rich phosphides and ferromagnetic Fe(Ni) fcc phases at higher temperatures. Both the Si-rich and the P-rich alloys have lower glass stability than the equiatomic one. At high temperatures, there is competition between the Fe(Si) bcc phase and its transformation in the ferromagnetic Fe(Ni) phase. Such a transformation is clearly apparent for the P-rich alloy. On the contrary, in the Si-rich alloy a third exothermic peak is obtained at high temperatures due to the formation of an fcc paramagnetic Ni(Fe) phase.