Coupling between small polarons and ferroelectricity in BaTiO3
arXiv:2503.12693 · doi:10.1103/5z43-rm34
Abstract
In this study, we investigate the formation of electron and hole small polarons in the prototypical ferroelectric material BaTiO3, with a focus on their interaction with ferroelectric distortive fields. To accurately describe the ferroelectric phase in electronically correlated BaTiO3, we employ the HSE06 hybrid density functional, which addresses the limitations of conventional density functional theory (DFT) and Hubbard-corrected DFT+U models, providing a more precise depiction of both ferroelectric and polaronic behaviors. Our analysis spans three structural phases of BaTiO3: cubic, tetragonal, and rhombohedral. We uncover a unique phase-dependent trend in electron polaron stability, which progressively increases across the structural phases, peaking in the rhombohedral phase due to the constructive coupling between the polaron and ferroelectric phonon fields. In contrast, hole polarons exhibit a stability pattern largely unaffected by the phase transitions. Furthermore, we observe that polaron self-trapping significantly alters the local ferroelectric distortive pattern, which propagates to neighboring sites but has a minimal effect on the long-range macroscopic spontaneous polarization. Charge trapping is also associated with localized spin formation, opening new possibilities for enhanced functionalities in multiferroic materials.
arXiv comment10 pages, 6 figures
References in corpus (14)
- Polaron percolation in diluted magnetic semiconductors
- On the Fermi Liquid to Polaron Crossover II: Double Exchange and the Physics of "Colossal" Magnetoresistance
- Watching the coherent birth of polaron pairs in conjugated polymers
- Origin of the crossover from polarons to Fermi liquids in transition metal oxides
- Polarons from first principles, without supercells
- Holstein polaron in a valley-degenerate two-dimensional semiconductor
- Interplay between adsorbates and polarons: CO on rutile TiO(110)
- Efficacy of the DFT+U formalism for modeling hole polarons in perovskite oxides
- Modelling charge self-trapping in wide-gap dielectrics: Localization problem in local density functionals
- The effect of intrinsic point defects on ferroelectric polarization behavior of SrTiO
- A variational polaron self-interaction corrected total-energy functional for charge excitations in wide-band gap insulators
- Photoexcited Small Polaron Formation in Goethite (α-FeOOH) Nanorods Probed by Transient Extreme Ultraviolet Spectroscopy
- Interplay between Ferroelectricity and Metallicity in BaTiO
- Understanding the role of Hubbard corrections in the rhombohedral phase of BaTiO