Abstract
Magnetically driven ferroelectric atomic displacements of the order of 10 Å have been observed in orthorhombic (perovskite like) YMnO by a single-crystal synchrotron x-ray diffraction. The refined polar structure shows the characteristic bond alternation driven by the exchange striction in staggered Mn-O-Mn arrays with type ordering, giving rise to a spontaneous polarization along the axis. First-principles calculations based on the Berry phase method as well as on the experimentally refined crystal structure can reproduce the observed polarization value.
- Received 23 May 2011
DOI:https://doi.org/10.1103/PhysRevB.84.054440
©2011 American Physical Society