Computer simulation of interdiffusion in polycrystalline thin film couples

Abstract: Computer simulation of superimposed lattice, grain boundary and surface diffusion, characteristic for polycrystalline thin film diffusion systems, was performed by way of discretisation of the nonlinear diffusion law. In order to give a vivid impression how such a complex process takes place under some typical conditions we have chosen pseudo three-dimensional computer plots of the spacial distribution of the concentration instead of the commonly used iso-concentration diagrams. The following cases are considered: <table><tr><td>a) </td><td> Polycristal — single crystal couple with highly diffusive grain boundaries and surfaces, grain boundaries and interface, grain boundaries, surfaces and interface. </td></tr><tr><td>b) </td><td> Polycrystal — polycrystal couple with different displaced grain boundaries as well as different diffusivity ratios for the bulk and the highly conducting regions. </td></tr></table>