The effect of composition on the crystallization and magnetic transition of Fe-Si-B amorphous alloys

This paper presents the effect of the metalloid composition on the crystallization and the magnetic phase transition of Fe-Si-B amorphous alloys. The phenomenon of two exothermic peaks (MS-I and MS-II phases) correlated with the crystallization behavior was examined by means of differential scanning calorimetry (DSC). The magnetic phase transition process was investigated by thermogravimetric analysis under a magnetic field (M-TGA). The microstructural evolution was studied by means of transmission electron microscopy (TEM). For the lower metalloid contents, the MS-I and MS-II phases were revealed to be a crystalline α-Fe structure and a compound structure with a large amount of metalloid elements, while for the higher metalloid contents, the compound of metalloid elements may be observed only in the MS-I phase. The precipitation temperature of the α-Fe phase exhibits a decreasing trend with increasing iron content. The Curie transition temperature of Fe-Si-B amorphous alloys also decreases with increasing iron content. The phase transitions of the DSC measurements were in good agreement with those measured by TGA under a magnetic field.