Hexagonal YbMnO3 revisited

The crystal structure of hexagonal ytterbium manganese oxide, YbMnO3, has been refined at room temperature. It is isomorphous with YMnO3. The Mn ions lie near the centre of a trigonal bipyramid. Although the Yb ions lie on threefold axes, the apical oxygen ions are at dissimilar distances, leading to ferroelectric behaviour. The sample studied was composed of almost an equal volume of inversion twins.