Applying a new interatomic potential for the modelling of hexagonal and orthorhombic YMnO3

Abstract

We develop and apply an interatomic potential for YMnO₃, based on the shell model together with the angular overlap model, which can model ligand field effects. The potential parameters accurately reproduce the complex structure of both hexagonal and orthorhombic phases of YMnO₃. The rotation of the MnO₆ octahedra in o-YMnO₃ suggests the E-type AFM order. The potential is further employed to investigate the energies of intrinsic defects in the material. Lower defect energies were found in o-YMnO₃. Oxygen Frenkel and Y₂O₃ partial Schottky are the most favourable defects in h-YMnO₃ and o-YMnO₃, respectively. The defect models proposed have implications for the properties of the related non-stoichiometric phases.