{
  "abstract": "Sodium niobate (NaNbO$_{3}$) is a perovskite oxide and a key component of emerging lead-free antiferroelectric capacitors for high-energy-density applications. However, its performance can be hindered by irreversible phase transitions and leakage currents associated with low electrical resistivity. Defect and doping engineering offers a potential way to overcome these problems, but its use requires a detailed understanding of electronic, ionic, and polaron charge-compensation mechanisms, where the role of polarons remains largely unexplored. Here, we investigate the stability of small hole and electron polarons in rhombohedral NaNbO$_{3}$, which is a structurally well-defined model system that avoids lattice-dynamical instabilities. Trapping energies are calculated using density-functional theory corrected by a Hubbard $U$, using the enforced-piecewise-linearity approach including finite-size scaling. For the small hole-polaron centered on O-2$p$ orbital, we find a trapping energy of $-$0.65 (eV) and an adiabatic migration barrier of 0.32 (eV) determined by nudged-elastic-band calculations. In contrast, we show that excess electrons do not self-trap on Nb-4$d$ orbitals, reflecting weak electron-phonon coupling in the conduction band manifold. These results identify oxygen as an intrinsic hole trap in NaNbO$_{3}$ and highlight the importance of including hole polarons in defect models of NaNbO$_{3}$-based electroceramics.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2605.18200",
  "author_total": 5,
  "authors": [
    {
      "name": "Mohammad Amirabbasi"
    },
    {
      "name": "Lorenzo Villa"
    },
    {
      "name": "Elaheh Ghorbani"
    },
    {
      "name": "Jochen Rohrer"
    },
    {
      "name": "Karsten Albe"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2fk5q76nyg1q5.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2605.18200",
  "fulltext_url": null,
  "id": "2fk5q76nyg1q5",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2605.18200",
  "language": null,
  "licence": "CC-BY-NC-SA-4.0",
  "licence_label": "CC BY-NC-SA 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-nc-sa/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.mtrl-sci"
    ],
    [
      "openalex",
      "2505|Ferroelectric and Piezoelectric Materials"
    ]
  ],
  "openalex": "W7161682728",
  "pdf_url": "https://arxiv.org/pdf/2605.18200",
  "pmcid": null,
  "pmid": null,
  "published": "2026-05-18",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/2fk5q76nyg1q5.ris",
  "sources": [
    {
      "first_seen": "2026-11-03T12:20:58Z",
      "native_id": "2605.18200",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2605.18200"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "First-principles investigation of small polarons in rhombohedral NaNbO$_{3}$",
  "title_text": "First-principles investigation of small polarons in rhombohedral NaNbO_3",
  "type": "preprint",
  "updated_at": "2026-11-05T15:20:17Z",
  "url": "https://research.draconitic.com/paper/2fk5q76nyg1q5",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1103/vyp9-s8zs",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}