Oxygen vacancy ordering and its mobility in YMnO 3

Oxygen vacancy (VO) ordering and its mobility in YMnO3 have been studied via electron-beam irradiation. By controlling the beam intensity, three commensurate (A, B and C-type) and one incommensurate VO-orderings can be formed. The transformation from the A-type to the C-type ordering has also been revealed, which could be attributed to the migration of VO from the apical VO site to the planar VO site. Further, intense irradiation can introduce more VOs and make a breakdown of the ferroelectric displacements of Y ions. These results suggest that the VOs in YMnO3 system are highly active in several ordered ways and also have a high mobility.