Reaction and diffusion at interfaces of micro- and nanostructured materials

Despite the technological importance of nanostructured materials, mass transport phenomena, such as diffusion and reaction, at interfaces are still poorly understood when nanoscale distances or short diffusion time are involved. In this paper, we present some typical examples concerning: (i) the initial stages of intermixing in a metallic Ni/Cu(1 1 1) heterostructure, (ii) the effect of biaxial stress on the diffusion of Sb in Si/Si1−xGex heterostructures and (iii) the influence of a Pt addition on the reaction sequence at a Ni(Pt)/Si interface. We show some surprising nanoscale effects such as: (i) layer-by-layer dissolution instead of total intermixing, (ii) increase of diffusion coefficients by a biaxial compression for a vacancy-mediated dopant and (iii) stabilisation in a large temperature domain of a non-equilibrium Ni(Pt)/Si interface.