Annealing ambient: A useful probe for interface interactions in thin films

The annealing ambient in thin-film diffusion studies is shown to be a useful probe for the interface interactions in thin films. The earlier proposed surface potential model for the ambient effects has been successful in correlating the known ambient effects and predicting new ones for many systems. Based on the concepts of this model, a catalytic mechanism is proposed in which the ambient species can accelerate or hinder the initial mixing process at the interfaces, thereby affecting all the diffusion and reactions that follow. An example is shown where the interdiffusion in the Au/Cr films in an air ambient can be completely suppressed by CO.