Influence of free surface and interfaces on diffusion coefficients in Pd-Ag and Pd-Au polycrystalline thin films systems

The influence of the interfaces on the diffusion in Pd films of Pd-Ag and P d-Au polycrystalline systems at a temperature near 500 K was studied. An X- ray diffraction technique based on the analysis of the profile change of li ne (111) in the diffusion zone was used. The decrement of the diffusion coe fficient in Pd film under transition from Pd-Ag-glass and Pd-Au-glass struc ture to Ag-Pd-glass and Au-Pd-glass structure was established. This result is explained by the influence of interphase surfaces on the mobility of dis locations along which the diffusion happens. (C) 2000 Elsevier Science B.V. All rights reserved.