Ck. Kim et al., Non-equilibrium crystallization diagram for the Co75.26-xFe4.74(BSi)(20+x)amorphous metal alloys, J MATER SCI, 36(19), 2001, pp. 4611-4616
A non-equilibrium crystallization diagram for Co sub-surface layers of the
Co75.26-xFe4.(74)(BSi)(20+x) amorphous alloy for x > 1 during magnetic fiel
d annealing is determined using Transmission Electron Microscopy (TEM). The
diagram shows that, depending on the composition and temperature, the Co s
ub-layer exhibits five distinctively different microstructures when the met
allic glass is heat treated below its bulk crystallization temperature. At
high boron content, the structure is dominated by the FCC structure with a
high degree of oxygen impurity faulting regardless of the annealing tempera
ture. At low concentration, the Co sub-layer exhibits FCC or HCP structures
, depending on the temperature. Also found was a two-phase region in which
FCC and HCP Co co-existed. Such a diagram serves as a useful guide to obtai
ning the desired properties as the microstructure is closely linked to the
magnetic properties of the material. (C) 2001 Kluwer Academic Publishers.