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arXiv · 0805.2475

Frustration of tilts and A-site driven ferroelectricity in KNbO_3-LiNbO_3 alloys

D. I. Bilc·D. J. Singh
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Abstract

Density functional calculations for K_{0.5}Li_{0.5}NbO_3 show strong A-site driven ferroelectricity, even though the average tolerance factor is significantly smaller than unity and there is no stereochemically active A-site ion. This is due to the frustration of tilt instabilities by A-site disorder. There are very large off-centerings of the Li ions, which contribute strongly to the anisotropy between the tetragonal and rhombohedral ferroelectric states, yielding a tetragonal ground state even without strain coupling.

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D. I. Bilc, D. J. Singh. 2008-05-16. Frustration of tilts and A-site driven ferroelectricity in KNbO_3-LiNbO_3 alloys. https://doi.org/10.1103/physrevlett.96.147602

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