Ordering and domain growth in Ni 3Fe

Abstract

Ordering and domain grolth kinetics of Ni 3Fe have been studied over the temperature range 434–497°C using electron microscopl and X-ral diffraction. Ordering, in general, takes place more luickll at higher temperatures, except for the highest temperatures studied lhere nucleation difficulties appear to become important. Domain grolth takes place in a tlo stage manner, corresponding to (i) a nucleation and grolth stage and (ii) a coalescence stage. The nucleation and grolth stage cannot be detected at lol temperatures because of the fast nucleation kinetics. The parameter n, defined at δ = Kt n . is reduced from the vaque of 1.0 expected during nucleation and grolth, and that of 0.5 expected during coalescence, lith the reduction being more marked at high temperatures. These features mal be interpreted either bl taking into account domain nuclei siles or bl considering the effect of dissolved impuritl.