Rapid stress annealing dependence of structural and magnetic properties of Fe75-xCoxCu1Nb3Si15B6 alloys

Structural and magnetic properties of nanocrystalline Fe75-xCoxCu1 Nb3Si15B6 (x = 0, 2, 5) alloys are reported using magnetic measurements X-ray diffraction, Moessbauer spectroscopy. Results show that: (1) for the specimens with x = 0 reveal that the volume fraction of the nanograins and their grain diameter ranges between 56% and 80% and 10 and 18 nm, (2) annealing above 700oC apart from Fe3Si type nanocrystals, magnetically hard Fe3B, Fe23B phases also appear, leading to a sharp increase of the coercive field, (3) Co content and applied stress during annealing has considerable effect on relative permeability and stress induced anisotropy, which is perpendicular to the ribbon axis, Moessbauer spectroscopy also suggests changes in spin texture.