Magnetism and57Fe Mössbauer effect in amorphous fe-base alloys: Significance of charge transfer and short-range atomic ordering

A review is given of the magnetic properties of amorphous A1-xFexalloys studied by bulk magnetic measurements and⁵⁷Fe Mössbauer spectroscopy (A=Mg,La, Lu,Y,Th,Hf,Zr,Ti,Nb,V,Mo,Ge,Si,B). Several mechanisms are discussed that can be held responsible for the reduction of the Fe moment observed upon alloying. The⁵⁷Fe isomer shift in most of the amorphous A1-xFexalloys was analysed in terms of the Miedema-Van der Woude model. On the basis of this analysis an experimental estimate of the amount of A-Fe charge transfer and intraatomic s-d electron conversion was obtained. It is shown that these two quantities are less relevant when dealing with the reduction in Fe moment upon combining A and Fe.