Fabrication of Ni–Al thin films by the pulsed laser deposition technique

We have fabricated Ni₃Al and NiAl thin films on different substrates by the pulsed laser deposition (PLD) technique. A high energy nanosecond laser beam was directed onto Ni–Al (NiAl, Ni₃Al) targets, and the evaporated material was deposited onto substrates placed parallel to the target. The substrate temperature was varied between 300 and 400 °C, and the substrate-target distance was maintained at approximately 5 cm. The films were analyzed using scanning electron microscopy, transmission electron microscopy, x-ray diffraction, and Rutherford backscattering spectrometry. At energy densities slightly above the evaporation threshold, a slight enrichment of Al was observed, while at higher energy densities the film stoichiometry was close (<5%) to the target composition. Barring a few particles, the surface of the films exhibited a smooth morphology. X-ray and TEM results corroborated the formation of Ni₃Al and NiAl films from similar target compositions. These films were characterized by small randomly oriented grains with grain size varying between 200 and 400 Å.