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Ab initio study of the phase diagram of epitaxial BaTiO3

Oswaldo Dieguez·Silvia Tinte·A. Antons·Claudia Bungaro·J. B. Neaton·Karin M. Rabe·David Vanderbilt
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Abstract

Using a combination of first-principles and effective-Hamiltonian approaches, we map out the structure of BaTiO3 under epitaxial constraints applicable to growth on perovskite substrates. We obtain a phase diagram in temperature and misfit strain that is qualitatively different from that reported by Pertsev et al. [Phys. Rev. Lett. 80, 1988 (1998)], who based their results on an empirical thermodynamic potential with parameters fitted at temperatures in the vicinity of the bulk phase transitions. In particular, we find a region of `r phase' at low temperature where Pertsev et al. have reported an `ac phase'. We expect our results to be relevant to thin epitaxial films of BaTiO3 at low temperatures and experimentally-achievable strains.

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Oswaldo Dieguez, Silvia Tinte, A. Antons, Claudia Bungaro, J. B. Neaton, Karin M. Rabe, David Vanderbilt. 2004-02-04. Ab initio study of the phase diagram of epitaxial BaTiO3. https://doi.org/10.1103/physrevb.69.212101

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