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arXiv · 1409.1731

Cation ordering induced polarization enhancement for $PbTiO_3$-$SrTiO_3$ ferroelectric-dielectric superlattices

Junkai Deng·Alex Zunger·Jefferson Zhe Liu
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Abstract

In this paper, an efficient computational material design approach (cluster expansion) is employed for the ferroelectric $PbTiO_3$/$SrTiO_3$ system. Via exploring a conguration space including over $3 \times 10^6$ candidates, two special cation ordered configurations: either perfect or mixed 1/1 (101) superlattice, are identified with the mostly enhanced ferroelectric polarization by up to about 100% in comparison with the (001) superlattice. Analyzing these two special configurations reveals the exotic couplings between the antiferrodistortive distortion (AFD) and ferroelectric polarization (FE) modes, e.g., tilting along x or y axis and polarization in z direction, as the origin for the best polarization property in this system. The identified cation ordering motifs and the exotic AFD-FE couplings could provide fresh ideas to design multifunctional perovskite heterostructures.

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Junkai Deng, Alex Zunger, Jefferson Zhe Liu. 2014-09-05. Cation ordering induced polarization enhancement for $PbTiO_3$-$SrTiO_3$ ferroelectric-dielectric superlattices. https://doi.org/10.1103/physrevb.91.081301

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