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Open Science and Research Project
OKFN, India
Polarization Enhancement in Perovskite
Superlattices by Oxygen Octahedral Tilts
X. Z. Lu, X. G. Gong, H. J. Xiang
Description
Interface engineering in perovskite oxide superlattices has developed into a flourishing field,
enabling not only further tuning of the exceptional properties, but also giving access to emergent
physical phenomena. Here, we reveal a new mechanism for enhancing the electric polarization by
the interfacial oxygen octahedral tilts in BaTiO3/CaTiO3 superlattices. By combining a novel
genetic algorithm with density functional theory (DFT), we predict that the true ground states in 1:1
and 2:2 BaTiO3/CaTiO3 superlattices grown on SrTiO3 adopt the Pc symmetry with a large electric
polarization (32.7{\mu}C/cm2 for 1:1 and 34.0 {\mu}C/cm2 for 2:2 superlattices), which is even
larger than that of bulk BaTiO3. The tilt of oxygen octahedron is found to play a key role for the
enhancement of out-of-plane polarization because it reduces greatly the rotation of oxygen
octahedron which significantly suppresses the out-of-plane polarization.
Cite as:
arXiv:1308.0076 [cond-mat.mtrl-sci]
(or arXiv:1308.0076v1 [cond-mat.mtrl-sci] for this version)
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