Abstract
We have studied the structural phase transition of multiferroic from first principles. Using group-theoretical analysis and first-principles density functional calculations of the total energy and phonons, we perform a systematic study of the energy surface around the prototypic phase. We find a single instability at the zone boundary which couples strongly to the polarization. This coupling is the mechanism that allows multiferroicity in this class of materials. Our results imply that is an improper ferroelectric. We suggest further experiments to clarify this point.
- Received 26 April 2005
DOI:https://doi.org/10.1103/PhysRevB.72.100103
©2005 American Physical Society