Monday, October 29, 2012

1210.7116 (Joseph W. Bennett et al.)

Orthorhombic $ABC$ semiconductors as antiferroelectrics    [PDF]

Joseph W. Bennett, Kevin F. Garrity, Karin M. Rabe, David Vanderbilt
We use a first-principles rational-design approach to identify a previously-unrecognized class of antiferroelectric materials in the $Pnma$ MgSrSi structure type. The MgSrSi structure type can be described in terms of antipolar distortions of the nonpolar $P6_{3}/mmc$ ZrBeSi structure type, and we find many members of this structure type are close in energy to the related polar $P6_{3}mc$ LiGaGe structure type, which includes many members we predict to be ferroelectric. We highlight known $ABC$ combinations in which this energy difference is comparable to the antiferroelectric-ferroelectric switching barrier of PbZrO$_{3}$. We calculate structural parameters and relative energies for all three structure types, both for reported and as-yet hypothetical representatives of this class. Our results provide guidance for the experimental realization and further investigation of high-performance materials suitable for practical applications.
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