Temperature dependent crystallization of amorphous Y67Fe33 studied using kinetic small angle neutron scattering

Temperature-resolved small angle neutron scattering (SANS) has been used to study the
nucleation, growth kinetics and crystallite morphology in the Y–Fe system. Crystallization from
amorphous Y67Fe33 to the YFe2 Laves phase via a novel ‘YFe’ intermediate phase has been
followed to completion as a function of temperature from 180 to 500 ◦C. The SANS results
agree well with published kinetic neutron diffraction data. Below 390 ◦C, diffraction data
suggest that SANS arises solely from the contrast between crystalline Y and the Fe-rich
amorphous matrix. Between 390 and 410 ◦C all temperature variables are seen to form a sharp
peak. This suggests that critical scattering occurs at Tc ≈ 400 ◦C. This critical scattering implies
that full crystallization of Y67Fe33 occurs over a very narrow (∼20 ◦C) temperature range.