Formation of metastable disordered Ni3Al by pulsed laser-induced rapid solidification

This paper reports on thin films of Ni3Al formed by co-evaporation onto insulating substrates which form a single phase fcc disordered lattice upon rapid solidification following excimer laser-induced melting with an interface velocity of ∼4 m/s. Transmission Electron Microscopy (TEM) and x-ray diffraction (XRD) analyses exhibit no superlattice diffraction at room temperature. Resistivity measurements, indicating that the disordered phase has a higher resistivity and much smaller temperature coefficient at room temperature than the stable ordered (Ll2) phase, permit the authors to monitor phase changes and ordering on a fast time-scale. Subsequent annealing recovers long-range order, with resistivity measurements indicating that reordering begins just below 300 degrees C