Nanocrystallization studies of rapidly quenched Fe85.4-xCoxZr6.8-yNbyB6.8Cu1 (X = 0 or 42.7, y = 0 or 1) alloys

The microstructure of amorphous and nanocrystalline Fe42.7Co42.7Zr6.8-xNbxB6.8Cu1 (x = 0 or 1) alloys was investigated. We have stated that the nanocrystalline samples consist of the crystalline α-FeCo grains of about 8 nm in diameter in an amorphous matrix which is rich in cobalt. From Moessbauer spectroscopy studies we have found that the crystalline α-FeCo phase in a nanocrystalline samples obtained by the conventional annealing is atomically ordered. Moreover, the order degree depends on the annealing time. As for the samples partially crystallized during rapid quenching the crystalline α-FeCo phase is atomically disordered. (author)