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arXiv · 1202.5481

First-principles simulations on the structural and energetic properties of domains in PbTiO$_3$/SrTiO$_3$ superlattices

Pablo Aguado-Puente·Javier Junquera
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Abstract

We report first-principles calculations, within the density functional theory, on the structural and energetic properties of 180$^\circ$ stripe domains in (PbTiO$_{3}$)$_{n}$/(SrTiO$_{3}$)$_{n}$ superlattices. For the explored periodicities ($n$=3 and 6) we find that the polydomain structures compete in energy with the monodomain phases. Our results suggest the progressive transition, as a function of $n$, from a strong to a weak electrostatic coupling regime between the SrTiO$_{3}$ and PbTiO$_{3}$ layers. Structurally, they display continuous rotation of polarization connecting 180$^\circ$ domains. A large offset between [100] atomic rows across the domain wall and huge strain gradients are observed. The domain wall energy is very isotropic, depending very weakly on the stripe orientation.

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Pablo Aguado-Puente, Javier Junquera. 2012-02-24. First-principles simulations on the structural and energetic properties of domains in PbTiO$_3$/SrTiO$_3$ superlattices. https://arxiv.org/abs/1202.5481

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