Mössbauer study of nanocrystalline Co60Fe30Ni10 and Co50Fe35Ni15 alloys obtained during mechanical synthesis

The mechanical alloying method was used to prepare Co60Fe30Ni10 and Co50Fe35Ni15 alloys from the elemental powders. As X-ray diffraction studies proved the final products of milling were the solid solutions with b.c.c. lattice and the average grain size of about 60 nm. After heating of the alloys up to 993 K, the mixtures of two solid solutions with a b.c.c. and f.c.c. lattices were formed. Annealing of the alloys at 1173 K for 1 h resulted in the formation of solid solutions with an f.c.c. lattice. Mössbauer spectroscopy revealed hyperfine magnetic field distributions which reflected the different surroundings of 57Fe isotopes by Co, Fe and Ni atoms, depending on the chemical composition of the alloy. The most probable atomic configurations were determined on the basis of a local environment model. The results of the macroscopic magnetic measurements testified that Co60Fe30Ni10 and Co50Fe35Ni15 alloys exhibited relatively good soft magnetic properties.