Argon ion-irradiation effects at the interface of Cu/Fe bilayers

Cu/Fe layers produced by molecular beam epitaxy were subjected to 360 keV A r+ irradiation at 180 K and 295 K over a range of ion fluences from 2.0 x 1 0(15) to 5.0 x 10(16) ions cm(-2). Rutherford backscattering spectrometry a nd x-ray diffraction were used to monitor the evolution of the interfaces a fter each step of irradiation. Up to fluences of approximately 5 x 10(15) A r+ cm(-2), at both substrate temperatures, a moderate decrease of the initi al Cu edge variance was observed. At higher fluences an inter-diffusion of the lavers was noticed. The results are interpreted as being caused by stre ss effects and plastic deformation.