Phys. Rev. B 110, 245302 (2024)

In this study, we investigate the construction of efficient model potentials for perovskite heterostructures by transferring relevant dynamic quantities from bulk systems and short-period superlattices. Through first-principles calculations, we provide a comprehensive analysis and comparison of the dynamical properties of different perovskite-based superlattice structures, including (PbTi⁢O3)𝑛/(SrTi⁢O3)𝑚 superlattices, (𝐴⁢Ti⁢O3)𝑛/(𝐴⁢O)2 superlattices, and 𝐴𝑛+1⁢T⁢i𝑛⁢O3⁢𝑛+1 Ruddlesden-Popper phases, where 𝐴 can be Sr, Ba, or Pb. We demonstrate that as the thickness of these structures increases, the dynamical properties of the perovskite blocks converge rapidly towards their bulk counterparts. We discuss this convergence in terms of phonon density of states in reciprocal space and interatomic force constants in real space. Our findings suggest a straightforward strategy for developing transferable model potentials that accurately capture the dynamics of layered oxide compounds with progressively thicker layers.

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