The spin-wave resonance study of concentrational inhomogeneities in nanocrystalline Ni-Fe-P and Ni-Fe-C alloys

The films of nanocrystalline Fe-Ni alloys obtained by various methods in th e permalloy composition range (similar to 20 at. % Fe) were studied by the method of spin-wave resonance (SWR) spectroscopy. The effective SW exchange stiffness eta (eff) exhibits a characteristic dependence on the spin wavel ength, which is indicative of the magnetization fluctuations in these films with a correlation radius of 12-20 nm. This is indirect evidence of the mi crophase separation in these nanocrystalline alloys and provides an estimat e of the characteristic spatial size of an inhomogeneity in the atomic rati o X-Fe/X-Ni . (C) 2001 MAIK "Nauka/Interperiodica".