First Principles Simulations on Migration Paths of Oxygen Interstitials in MgAl2O4

Abstract

Thermal stability of the primary electronic defects – F‐type centers – in oxide materials is controlled by their recombination with much more mobile complementary defects – interstitial oxygen ions Oi. Thus, the study of interstitial ion migration is of key importance for the prediction of radiation damage in oxides. In this study, several possible migration trajectories for neutral and charged interstitial oxygen ions are calculated in MgAl2O4 spinel using the first principles calculations of atomic and electronic structure. The lowest energy barriers are ≈1.0–1.1 eV and 0.8 eV, respectively. The effective atomic charges, charge redistribution, and lengths of bonds closest to Oi interstitials are analyzed in detail.