{
  "abstract": "Palmierite oxides are promising oxide-ion conductors, with conductivities exceeding those of related hexagonal perovskite derivatives. However, aliovalent Mo6+ substitution in Ba 3 V 2 O 8 has previously been demonstrated only at high substitution levels. Here, the Ba 3 V 2-x Mo x O 8+x/2 series (0 ≤ x ≤ 0.3) was investigated using X-ray and neutron powder diffraction, 51 V and 17 O solid-state NMR spectroscopy combined with density functional theory (DFT), and bond-valence site-energy (BVSE) calculations. Combined Rietveld refinement reveals that Mo6+ substitution introduces a charge-compensating interstitial oxygen site (O3) at x = 0.3, transforming isolated (V, Mo)O 4 tetrahedra into corner-sharing polyhedra with mixed coordination. DFT-supported 17 O NMR identifies additional oxygen environments associated with Mo in four- and five-fold coordination, suggesting oxygen bridges between adjacent MoO5 polyhedra. 51 V NMR confirms predominantly tetrahedral vanadium coordination, alongside a minority V environment , distorted by occupation of a nearby O3 site. BVSE calculations indicate that O3 bridges neighboring polyhedra in the abplane, enabling a low-barrier, two-dimensional oxide-ion migration pathway involving apical O1 and interstitial O3 sites. These findings establish interstitial oxygen incorporation as the key structural mechanism facilitating low-barrier two-dimensional oxide-ion transport at low Mo substitution levels in the palmierite family, with broader implications for hexagonal perovskite ionic conductors.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Radiation Science and Technology",
    "Delft University of Technology",
    "Inorganic Chemistry Laboratory",
    "University of Oxford",
    "Helmholtz Zentrum Berlin für Materialien und Energie"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Abdulkadir Olatunbosun Biffo"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Anastasia K. Lavrinenko"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Hailin Ma"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Shengnan Zhang"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Alexandros Vasileiadis"
    },
    {
      "affs": [
        0,
        1,
        2,
        3
      ],
      "name": "Theodosios Famprikis"
    },
    {
      "affs": [
        0,
        1,
        4
      ],
      "name": "Pedro B. Groszewicz"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/d1sf8mfdx8w3t.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010854/v1",
  "fulltext_url": null,
  "id": "d1sf8mfdx8w3t",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010854/v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2505|Advancements in Solid Oxide Fuel Cells"
    ]
  ],
  "openalex": "W7223187038",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-22",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/d1sf8mfdx8w3t.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:24Z",
      "native_id": "10.26434/chemrxiv.15010854",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010854/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2505|Advancements in Solid Oxide Fuel Cells",
      "subfield": "electrochemistry-energy"
    }
  ],
  "title": "Interstitial Oxygen and a Two-Dimensional Migration Pathway in Mo-Substituted Palmierite Ba ₃ V 2−x Mo x O 8+x/2",
  "title_text": "Interstitial Oxygen and a Two-Dimensional Migration Pathway in Mo-Substituted Palmierite Ba ₃ V 2−x Mo x O 8+x/2",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:24Z",
  "url": "https://research.draconitic.com/paper/d1sf8mfdx8w3t",
  "venue": "ChemRxiv",
  "versions": []
}