Thermal reactions between aluminum and palladium layered films

Abstract

Phase formation and reaction during annealing in thin film couples of aluminum and palladium were studied by transmission electron microscopy, X-ray diffraction and Auger depth profiling techniques in the temperature range 200- 500°C. The known bulk phases of Al3Pd2, AlPd, Al3Pd5 and AlPd2 were confirmed and two additional aluminum-rich phases were tentatively identified as Al3Pd and Al4Pd. In all the samples studied the reactions were initiated by the formation of the β-AlPd phase, which was then followed by the formation of the Al3Pd2 phase. Subsequent reactions caused precipitation of AlPd2 particles if unreacted palladium was present, otherwise Al4Pd particles were precipitated. The reaction rate was usually reduced if single-crystal, instead of polycrystalline, palladium film was used. © 1980.