Iryna L. Microstructural transformations in condensed matter systems under irradiation influence

The dissertation is devoted to study microstructural transformations in condensed matter systems under irradiation influence. It was found that microstructural transformation processes in one-component crsytalline and binary systems subjected to irradiation influence can be controlled by statistical properties of fluctuations of irradiation flux, which leads to stochastic scenario for atomic mixing forced by interactions with high energetic particles. It is shown that due to competition between regular and stochastic components of irradiation flux the ordering processes can be induced by fluctuations of lengths of disturbed atoms. Spatial pattern selection processes under condition of non-commensurable time scales for thermally sustained and ballistic diffusion fluxes are studied in details. It was found that formation of ordered phase at phase decomposition is realized in reentrant manner, i.e. in a fixed interval for intensity of fluctuations of irradiation flux. In the domain of phase decomposition the grain size growth law of the Lifshitz-Slyozov type is realized. Properties of surface morphology changes in amorphous materials under ion-beam sputtering with fluctuations of an incidence angle are studied. It was found a critical influence of teh secondary characteristics of ion beam related to intensity fo incident angle fluctuations and a corresponding correlation scale. Scaling properties of such systems are described.