Electron Doping Stabilization of Highly-Polar Supertetragonal BaSnO3

Fuente: arXiv
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Autores principales: Zhang, Qing, Rabe, Karin M., Liu, Xiaohui
Formato: Preprint
Publicado: 2025
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author Zhang, Qing
Rabe, Karin M.
Liu, Xiaohui
author_facet Zhang, Qing
Rabe, Karin M.
Liu, Xiaohui
contents Could electrons stabilize ferroelectric polarization in unpolarized system? Basically, electron doping was thought to be contrary to polarization due to the well-known picture that the screening effect on Coulomb interaction diminishes ferroelectric polarization. However, in this paper, we propose a novel mechanism of stabilizing highly-polar supertetragonal BaSnO3 by electron doping. With moderate compressive strain applied, less than -5.5%, BaSnO3 exhibits stable nonpolarized normal tetragonal structure and an unstable supertetragonal state which is characterized with extremely large c/a ratio and giant polarization. We found that the band gap of the supertetragonal state is much smaller than the normal tetragonal state, with a difference around 1.2eV. Therefore, the energy of the doped electrons selectively favors the smaller gap supertetragonal state than the larger band gap normal tetragonal state, and the critical strain to stabilize the supertetragonal phase could be reduced by electron doping. This mechanism guarantees the controllable supertetragonal structures by electron doping and ensures the coexistence of giant polarization and conducting in high-mobility BaSnO3, and is promising to design high-mobility ferroelectrics conductor.
format Preprint
id arxiv_https___arxiv_org_abs_2507_23649
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Electron Doping Stabilization of Highly-Polar Supertetragonal BaSnO3
Zhang, Qing
Rabe, Karin M.
Liu, Xiaohui
Materials Science
Could electrons stabilize ferroelectric polarization in unpolarized system? Basically, electron doping was thought to be contrary to polarization due to the well-known picture that the screening effect on Coulomb interaction diminishes ferroelectric polarization. However, in this paper, we propose a novel mechanism of stabilizing highly-polar supertetragonal BaSnO3 by electron doping. With moderate compressive strain applied, less than -5.5%, BaSnO3 exhibits stable nonpolarized normal tetragonal structure and an unstable supertetragonal state which is characterized with extremely large c/a ratio and giant polarization. We found that the band gap of the supertetragonal state is much smaller than the normal tetragonal state, with a difference around 1.2eV. Therefore, the energy of the doped electrons selectively favors the smaller gap supertetragonal state than the larger band gap normal tetragonal state, and the critical strain to stabilize the supertetragonal phase could be reduced by electron doping. This mechanism guarantees the controllable supertetragonal structures by electron doping and ensures the coexistence of giant polarization and conducting in high-mobility BaSnO3, and is promising to design high-mobility ferroelectrics conductor.
title Electron Doping Stabilization of Highly-Polar Supertetragonal BaSnO3
topic Materials Science
url https://arxiv.org/abs/2507.23649