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Theoretical phase diagram of ultrathin films of incipient ferroelectrics

A. R. Akbarzadeh·L. Bellaiche·Jorge Íñiguez·David Vanderbilt
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Abstract

We have used a first-principles-based scheme to compute the temperature-versus-misfit strain ``Pertsev'' phase diagram of ultrathin films of {\sl incipient} ferroelectric KTaO$_3$. Our results suggest that, at variance with the bulk material, KTaO$_3$ ultrathin films cannot be described as quantum paraelectrics. Rather, the behavior of the films is largely determined by surface/interface effects that favor ferroelectricity and the imperfect screening of the depolarizing fields. This leads to Pertsev phase diagrams that are qualitatively similar to those of {\sl normal} ferroelectrics such as BaTiO$_3$.

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A. R. Akbarzadeh, L. Bellaiche, Jorge Íñiguez, David Vanderbilt. 2007-02-12. Theoretical phase diagram of ultrathin films of incipient ferroelectrics. https://doi.org/10.1063/1.2748844

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