Abstract
We study the formation of the icosahedral Al-Cu-Fe quasicrystalline phase in heat-treated elemental multilayers. Pure quasicrystalline films can be obtained in similar annealing conditions independently of the stacking sequence of the multilayers. Using synchrotron radiation diffraction, we study in real time the succession of the intermediate phases formed during ramp heat treatments of Al/Cu/Fe/Cu/Al and Al/Fe/Cu/Fe/Al sandwiches. Al-Cu binary phases are first formed in the early stages for both stacking sequences, despite the presence of Fe layers between Al and Cu in the second configuration. The role played by Fe is discussed. The transient formation of θ-Al3Fe is not observed, although it was believed to be a necessary precursor for the quasicrystal formation.