We report our recent discovery of novel ferroelectricity arising from the polar ordering of Fe3+ and Fe2+ in a mixed valence triangular lattice oxide LuFe2O4, where the electric polarization is not a result of ionic displacement. The polar ordering of Fe3+ and Fe2+ was confirmed with a resonant x-ray scattering study in SPring-8. The origin of such ordering is the competitive interaction between Fe3+ and Fe2+ in the triangular lattice, i.e., the charge frustration. The polar superlattice of Fe3+ and Fe2+ develops below 350 K, where the electric polarization appears. The ferroelectricity arising from the polar charge ordering or the polar electron distribution may have great potential for the future application of ferroelectrics.
|Number of pages||3|
|Journal||IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control|
|Publication status||Published - May 2008|
ASJC Scopus subject areas
- Acoustics and Ultrasonics
- Electrical and Electronic Engineering