Ab initio modelling of the Y, O, and Ti solute interaction in fcc-Fe matrix

Strengthening of the ODS steels by Y2O3 precipitates permits to increase their operation temperature and radiation resistance, which is important in construction materials for future fusion and advanced fission reactors. Both size and spatial distribution of oxide particles significantly affect mechanical properties and radiation resistance of ODS steels. Addition of the Ti species (present also as a natural impurity atoms in iron lattice) in the particles of Y2O3 powder before their mechanical alloying leads to the formation of YTiO3, Y2TiO5, and Y2Ti2O7 nanoparticles in ODS steels. Modelling of these nanoparticle formation needs detailed knowledge of the energetic interactions between ions. We have performed detailed first principles calculations of the interactions between two Y and O atoms, two Ti and O atoms as well as between Y, Ti, and O atoms which will be used in further kinetic Monte Carlo modelling of the nanoparticle formation.