Comparative study on phase formation in Al-Pd thin film by ion beam mixing and thermal annealing

Ion beam mixing and/or thermal annealing were carried out to study phase formation and dissociation in Al-Pd thin films. The films were prepared by sequential evaporation, Ar+ ion mixing and annealing at 350oC for 1 h under vacuum. They were then analysed by Rutherford backscattering, transmission electron microscopy and X-ray photoelectron spectroscopy. The intermetallic compounds formed by ion mixing alone are found to be Al3Pd2 and AlPd at a dose of 1.5 x 1016 Ar+ cm -2. Thermal annealing after this radiation gave two new phases of Al3Pd and Al3Pd5 in addition to Al3Pd2 and AlPd. For an as-annealed sample without Ar+ bombardment, the observed phases are Al3Pd, Al3Pd2 and AlPd. The difference in phase formation behaviour between ion beam mixing and thermal annealing are presented. (author)