{
  "abstract": "Rare-earth nickelates are among the most active oxide electrocatalysts for the oxygen evolution reaction (OER), owing to their tunable Ni-O covalency, near-unity eg occupancy, and sensitivity to A-site chemistry, oxygen stoichiometry, and epitaxial strain. Here, we use epitaxial A-site high-entropy (La0.2Pr0.2Nd0.2Sm0.2Eu0.2)NiO3 thin films to reveal how epitaxial strain influences defect formation, Ni valence, electronic structure, and OER activity in a chemically disordered rare-earth (RE) sublattice. Tensile strain promotes Ruddlesden-Popper fault formation, interrupts the corner-sharing NiO6 network, and lowers the average Ni oxidation state. Although the occupied density of states near the Fermi level remains largely unchanged, O K-edge X-ray absorption spectroscopy reveals increased low-energy unoccupied states under tensile strain. First-principles calculations suggest that tensile strain shifts RE 4f-derived states toward the Fermi level, enhancing RE 4f-O 2p-Ni 3d hybridization. These coupled structural and electronic changes lead to earlier OER onset, stronger pre-catalytic Ni redox features, and higher activity than compressively strained films and representative single-A-site nickelates. The high-entropy nickelate also shows enhanced resistance to OER-induced structural degradation compared with LaNiO3. These results suggest that A-site configurational disorder and epitaxial strain can jointly tune defect formation and rare-earth-derived electronic states, providing a route for improving perovskite oxide electrocatalysts.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.02796",
  "author_total": 13,
  "authors": [
    {
      "name": "Min-Ju Choi"
    },
    {
      "name": "Le Wang"
    },
    {
      "name": "Krishna Prasad Koirala"
    },
    {
      "name": "Hyoju Park"
    },
    {
      "name": "Mark E. Bowden"
    },
    {
      "name": "Elizabeth Helen Krenkel"
    },
    {
      "name": "Aiping Chen"
    },
    {
      "name": "Jueli Shi"
    },
    {
      "name": "Conan Weiland"
    },
    {
      "name": "Iradwikanari Waluyo"
    },
    {
      "name": "Adrian Hunt"
    },
    {
      "name": "Peter V. Sushko"
    },
    {
      "name": "Yingge Du"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ch1ykavvnynf2.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.02796",
  "fulltext_url": null,
  "id": "ch1ykavvnynf2",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.02796",
  "language": null,
  "licence": "CC-BY-NC-ND-4.0",
  "licence_label": "CC BY-NC-ND 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.mtrl-sci"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2611.02796",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-02",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ch1ykavvnynf2.ris",
  "sources": [
    {
      "first_seen": "2026-11-03T12:20:59Z",
      "native_id": "2611.02796",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.02796"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "High-Entropy A-Site Disorder Enhances Oxygen Evolution Reaction Activity and Stability in Nickelate Thin Films",
  "title_text": "High-Entropy A-Site Disorder Enhances Oxygen Evolution Reaction Activity and Stability in Nickelate Thin Films",
  "type": "preprint",
  "updated_at": "2026-11-05T15:20:18Z",
  "url": "https://research.draconitic.com/paper/ch1ykavvnynf2",
  "venue": "arXiv",
  "versions": []
}