Atomistic simulation of dynamical and defect properties of multiferroic hexagonal YMnO3

Atomistic simulation has been performed to investigate the dynamical and defect properties of multiferroic hexagonal YMnO3 with newly developed interaction potentials. Dynamical calculation reveals that phonon vibrations of hexagonal YMnO3 are quite different from those of orthorhombic YMnO3. Defect calculation finds that O Frenkel is the most probable intrinsic disorder, and Mn antisite defect is favorable to exist, especially for Mn ions entering the Y2 sites. It is also found that holes prefer to localize at O-2. sites rather than at Mn3+ sites, while the electron can be localized at the Mn3+ site. The disproportionation of Mn3+ ions is unlikely to occur in hexagonal YMnO3.