CHRONOAMPEROMETRY FOR THE DETERMINATION OF METALLIC INTERDIFFUSION COEFFICIENTS - RAPID-TRANSPORT PROCESSES IN THE FIRST ATOMIC LAYERS

The potential step technique was used to study the interdiffusion in t he solid state at high temperature using a molten electrolyte. The met hod was applied to several binary metal systems and proved to be effic ient for the determination of the interdiffusion coefficient D as a fu nction of the temperature and composition of the generated alloys. The electrochemical response at short times showed a net departure from t he usual diffusion laws and could be interpreted in terms of a very fa st transport in the initial layers of the metal interface. Analysis of the transients was carried out by digital simulation in order to take into account the dependence of D on the concentration and distance.