Crystallization-nitriding process of FeSiB and FeSiBCuNb ribbons: influence of additive (Cu,Nb) pair and nitrogen on structure, magnetic and magnetostrictive parameters

Both conventional thermal treatments (CTTs) and nitriding thermochemical treatments (NTTs) are used to crystallize Fe₇₄Si₁₄B₁₂ and Fe_73.5Si_13.5B₉Cu₁Nb₃ melt spun ribbons. For the FeSiB sample, nitrogen is detected throughout the whole thickness, while nitrogen is observed only in the periphery of the (Cu–Nb) containing sample. Nitrogen diffusion is related to the crystallization. The remaining phase in the nanocrystallized FeSiBCuNb sample slows down the nitrogen diffusion. This kind of treatment applicated to FeSiBCuNb sample enables the formation of nanocrystallites with a grain size that is slightly smaller than that obtained following a CTT.