Podolyan O. Phenomenological models of diffusion-controlled processes of voiding and segregation in binary nanoparticles and mesosystems

The dissertation is devoted to investigation of the voiding and segregation processes in binary "core/shell" system with the different diffusion mobilities of system's components. Phenomenological models of pore formation and shrinkage in binary solutions and compounds of nanowires are built. A qualitative comparative analysis of the results with experimental data and results for the nanospheres is given. The possibility of reduction a component of compound during the hollow nanoshell shrinking is analyzed. The model based on the boundary kinetics is built to describe the initial stage of nucleation taking into account the influence of curvature, deviation from the equilibrium concentration boundary values and concentration dependence of the average diffusion coefficient. It is shown that as during the shrinkage under Laplace pressure difference between the outer and inner nanoshell's boundaries as in the diffusion creep with concentration gradients caused by mechanical loading nonequilibrium segregation rate of rapid component is determined by the slow component. Electromigration in a two-phase mixture (solder) leads to a complete separation of the components and the separation rate is determined by the structure of the alloy.