Ab initio modelling of Y–O cluster formation in γ-Fe lattice

Ab initio modelling of Y and O impurity atoms as well as V_Fe vacancies in the fcc-Fe lattice is performed in order to calculate the interactions between these defects, which are important for understanding of nanoparticles’ formation within the oxide dispersed strengthened steels. Large scale parallel calculations based on plane-wave method realised in VASP computer code show that V_Fe vacancies considerably influence the binding between the impurity atoms. In this study, we present the results of performed calculations providing the detailed information about the binding energies between the defects, the changes of their effective charges as well as displacements of the substitute atoms relatively the host atom positions. The energy barriers for the migration trajectories of impurity atoms have been also found by performing the large-scale calculations within the nudge elastic band method.