ION-BEAM MIXING IN AU-AL THIN-FILM BILAYERS

The formation of intermetallic compounds in Au-Al thin film bilayers induced by ion implantation were investigated using 2. 0 MeV He backscattering and X-ray diffraction techniques. Kr ions of energy in the 60-240 keV range and fluence in the 10**1**5-10**1**6/cm**2 interval were used to bombard targets at LN//2 temperature. After irradiation of an Al-Au pair the two compounds Au//2Al and AuAl//2 are formed. The relative amount of nucler energy deposited in the Au and Al layers determines not only the final phase (AuAl//2 or Au//2Al) but also their growth rate. The results seem to indicate that the process is mainly governed by the supply of one or of the other element. This supply is related to the number of atoms which have received a sufficient energy during the collision.