{
  "abstract": "Defect states directly influence not only functional properties, but also oxynitride formation during ammonolysis. Along with structural stability and charge balance, these defects can cause non-uniform nitrogen incorporation. To address this, the recently proposed Fermi Level Engineering concept provides a powerful alternative of rationalising oxynitride synthesis. By using the electron chemical potential, i.e., the Fermi level, as a unique descriptor, this approach can predict, understand, and manipulate defect formation enthalpies and charge transition levels, subsequently allowing to incorporate defect-property correlations to the concept. This work combines theoretical modelling and experimental characterisation of barium titanium oxynitrides to explain an intrinsic, self-limiting nitridation process. Progressive nitrogen incorporation causes a Fermi level downward shift, leaving further nitrogen substitution on oxygen sites energetically unfavourable, up to 0.03 N per unit formula. We demonstrate that A-site cation substitution in Eu$_{1-x}$Ba$_x$TiO$_3$- and Eu$_{1-x}$Ca$_x$TiO$_3$-derived oxynitrides can be applied to control compensation of the additional negative charge from N$^{3-}$ and keep the Fermi level high. The Eu$^{2+/3+}$ redox couple enables substitution of oxygen by nitrogen through pinning of the Fermi level at the europium charge transition level, at $\\sim$ 2.9 eV above the VBM. This allows for higher nitrogen uptake of up to 0.65 per formula unit (taken from hot gas extraction) through a more controlled process. Further incorporation is then limited by an intra-Ti(O,N)$_6$ octahedra distortion due to internal bond-angle variance. These findings demonstrate that Fermi Level Engineering provides a pathway to predict and overcome intrinsic synthetic and thermodynamic limitations in oxynitride synthesis.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.04745",
  "author_total": 19,
  "authors": [
    {
      "name": "Margarida Barroso"
    },
    {
      "name": "Marie Neumann"
    },
    {
      "name": "Rachele Sciotto"
    },
    {
      "name": "Shama Perween"
    },
    {
      "name": "Magdalena O. Cichocka"
    },
    {
      "name": "Jefferson Bettini"
    },
    {
      "name": "Adrián López Vergara"
    },
    {
      "name": "Patrick Zeller"
    },
    {
      "name": "Gaurav Anand"
    },
    {
      "name": "Verena Streibel"
    },
    {
      "name": "Barbara A. J. Lechner"
    },
    {
      "name": "Melanie Appelmann"
    },
    {
      "name": "Oliver Clemens"
    },
    {
      "name": "Ute Kolb"
    },
    {
      "name": "Jan P. Hofmann"
    },
    {
      "name": "Karsten Albe"
    },
    {
      "name": "Andreas Klein"
    },
    {
      "name": "Marc Widenmeyer"
    },
    {
      "name": "Anke Weidenkaff"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/d39w923s5d2pe.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.04745",
  "fulltext_url": null,
  "id": "d39w923s5d2pe",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.04745",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.mtrl-sci"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2611.04745",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-03",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/d39w923s5d2pe.ris",
  "sources": [
    {
      "first_seen": "2026-11-04T15:21:25Z",
      "native_id": "2611.04745",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.04745"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Controlling nitrogen incorporation in (Eu,Ba,Ca)TiO$_3$-derived perovskite-type oxynitrides through Fermi Level Engineering",
  "title_text": "Controlling nitrogen incorporation in (Eu,Ba,Ca)TiO_3-derived perovskite-type oxynitrides through Fermi Level Engineering",
  "type": "preprint",
  "updated_at": "2026-11-06T18:21:01Z",
  "url": "https://research.draconitic.com/paper/d39w923s5d2pe",
  "venue": "arXiv",
  "versions": []
}