Self-Organization of an Ensemble of Vacancies under the Spinodal Decomposition of Binary Systems at Continuous Irradiation

Abstract

The redistribution processes of non-equilibrium vacancies under the spinodal decomposition in a continuously irradiated solid solution have been considered. The consideration is carried out in the framework of the generalized Cahn-Hilliard model, which makes allowance for the structural disorder formation under irradiation. As the defect production rate increases, the spinodal decomposition processes are found to transform into the processes of vacancy pattern formation. It is shown that the formation of vacancy clusters is accompanied by the pattern selection processes. The decomposition and patterning kinetics, as well as the statistical distributions of solute and vacancy concentrations at various dose rates are studied. K e y w o r d s: Cahn-Hilliard model, spinodal decomposition in binary systems.

Phase field modelling voids nucleation and growth in binary systems

“…A growth in (δψ) 2 indicates the formation of an ordered configuration where the domains of two phases emerge during the system evolution. The obtained results correspond well to previous studies of a vacancy rearrangement in binary systems with soft and hard phases [48,49]. It was shown that at phase decomposition, the above rearrangement of vacancies is a result of Kirkendall effect occurring in the systems with different self-diffusivities of atoms of two sorts.…”

“…The development of Darken's approach in binary systems under irradiation, where vacancies are capable of organizing into voids was discussed in [47]. Properties of patterning in a two-component system caused by vacancy rearrangement at irradiation and the corresponding discussions of the Kirkendall effect were provided in [48,49]. In most of the works related to the study of the void evolution, point defects were described by their populations and all classifications of defect patterns were done by considering the corresponding values of point defect concentrations, whereas no special quantity identifying a different kind of objects having dimensions larger than zero was introduced.…”