Effect of thermal treatment on the magnetization processes of nanocrystalline Fe80Ge3Nb10B7 alloys

► Nanocrystallization and magnetic properties of Fe80Ge3Nb10B7 alloy were studied. ► Permeability spectra reveals that magnetization process varies with the annealing time. ► 973 K annealing may result in Fe3Ge, which deteriorates soft magnetism. ► Domain wall bulging and displacement are main magnetization mechanisms. ► Pinning sites and their distribution determine the magnetic performance.