Abstract
Despite recent interest in Bi-containing layered-perovskite ferroelectrics due to high , their rational design is constrained by a poor understanding of local atomic structures. Here, we use neutron total scattering and first-principles theory to examine the local atomic structure in Dion-Jacobson layered-perovskite ferroelectric . We show that the instantaneous short-range atomic structure can be described by a Debye-Einstein model that accommodates atomic motions due to acoustic and low-energy optic phonon modes. We determine structural distortions due to localized atomic dynamics with extremely high resolution. These are in addition to ground-state relative ionic displacements. The magnitude of dynamic variations in ionic positions points toward strong electron-phonon coupling in this material.
- Received 11 April 2022
- Revised 10 June 2022
- Accepted 21 June 2022
DOI:https://doi.org/10.1103/PhysRevB.106.024103
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