Investigation of magnetic properties of Fe61Co8Zr4−xY2+xNi5Nb5B15 amorphous alloys (x = 0, 1) in the form of ribbons

► Influence of minor changes of the Zr and Y content in the alloy composition on the microstructure and magnetic properties of Fe61Co8Zr4+xY2−xNi5Nb5B15 amorphous alloys was studied. ► The X-ray technique is not feasible for identification of fcc (Fe, Co)23B6 configuration which may develop in the investigated amorphous matrix systems. ► The saturation magnetization for both alloys was of about 1 T. ► Alloy with 4% Zr content had higher permeability, was characterized by much smaller core losses and the coercivity was approximately half that of the alloy with 3% Zr content.