Ambient effects on the diffusion of Cr and Si in thin Pt films

We have studied the ambient effects on the low-temperature diffusion of Cr and Si in thin Pt films. The surface-potential model proposed earlier predicts that, contrary to the case in gold, oxygen should suppress the diffusion of Cr and Si in Pt. We have observed a reduced out-diffusion of Cr and a reduced rate of Pt2Si formation in the prseence of O2. The technological significance of this effect is also discussed.