Modeling the migration of an intercalated oxygen atom in the YCrO3+δ structure using density functional theory

Abstract

The migration of an interstitial oxygen atom in the YCrO₃ perovskite structure was investigated using density functional theory. Activation barriers for oxygen migration were calculated along different crystallographic directions. The results indicate that oxygen migration within the CrO₂-(001) and (110) planes occurs with barriers of approximately 0.5 eV, whereas transitions between these planes require higher barriers, around 1 eV. A detailed analysis of the electronic structure during oxygen migration revealed significant changes, including energy level shifts in bonding molecular orbitals formed by the overlap of the interstitial oxygen’s p-orbitals and the d_xy orbitals of neighboring Cr atoms. This study highlights redox processes involving Cr atoms adjacent to the migrating oxygen atom, providing new insights into defect transport mechanisms in YCrO₃ and their potential impact on its electronic and magnetic properties.