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Epitaxially strained [001]-(PbTiO$_3$)$_1$(PbZrO$_3$)$_1$ superlattice and PbTiO$_3$ from first principles

Claudia Bungaro·K. M. Rabe
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Abstract

The effect of layer-by-layer heterostructuring and epitaxial strain on lattice instabilities and related ferroelectric properties is investigated from first principles for the [001]-(PbTiO$_3$)$_1$(PbZrO$_3$)$_1$ superlattice and pure PbTiO$_3$ on a cubic substrate. The results for the superlattice show an enhancement of the stability of the monoclinic r-phase with respect to pure PbTiO$_3$. Analysis of the lattice instabilities of the relaxed centrosymmetric reference structure computed within density functional perturbation theory suggests that this results from the presence of two unstable zone-center modes, one confined in the PbTiO$_3$ layer and one in the PbZrO$_3$ layer, which produce in-plane and normal components of the polarization, respectively. The zero-temperature dielectric response is computed and shown to be enhanced not only near the phase boundaries, but throughout the r-phase. Analysis of the analogous calculation for pure PbTiO$_3$ is consistent with this interpretation, and suggests useful approaches to engineering the dielectric properties of artificially structured perovskite oxides.

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Claudia Bungaro, K. M. Rabe. 2003-12-02. Epitaxially strained [001]-(PbTiO$_3$)$_1$(PbZrO$_3$)$_1$ superlattice and PbTiO$_3$ from first principles. https://doi.org/10.1103/physrevb.69.184101

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