{
  "abstract": "Sc-alloyed wurtzite nitrides exhibit strongly tunable electromechanical and ferroelectric properties, yet the relationship between their lattice evolution and local bonding environment remains insufficiently established, particularly in Sc$_x$Ga$_{1-x}$N. Here, we investigate the structural and local bonding evolution of Sc$_x$Ga$_{1-x}$N across the dilute-to-intermediate composition range by combining X-ray diffraction, Sc K-edge X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS) and first-principles calculations. Sc incorporation produces an anisotropic lattice expansion and a progressive reduction in the c/a ratio. XANES and EXAFS reveal a concurrent modification of the local environment around Sc, with the effective Sc-N coordination number increasing from 4.1(4) to 4.5(2) and the average Sc-N bond length increasing from 2.045(7) to 2.081(8)Å over x=0.06-0.26. The local response is accompanied by a reduction in the Sc K-edge pre-edge intensity, consistent with a gradual reduction of the local tetrahedral asymmetry. First-principles calculations show that these structural changes are associated with site-selective distortions around Sc and progressive flattening of the structural energy landscape. The calculated intrinsic polarization-switching barrier decreases from 24.2 to 19.0 meV/Å$^3$ with increasing Sc content, while the calculated piezoelectric stress coefficient (e$_{33}$) increases from 0.82 to 1.66~C/m$^2$ and elastic constant (C$_{33}$) decreases from 380 to 227~GPa, resulting in an increase of piezoelectric strain coefficient (d$_{33}$) from 2.99 to 12.46~pC/N. These results show that Sc incorporation progressively modifies the local coordination environment and structural energetics of ScGaN while the long-range wurtzite structure remains preserved over the investigated composition range.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.05000",
  "author_total": 11,
  "authors": [
    {
      "name": "Shailesh Kalal"
    },
    {
      "name": "Gueorgui Kostov Gueorguiev"
    },
    {
      "name": "Martin Magnuson"
    },
    {
      "name": "Edward Ferraz de Almeida Junior"
    },
    {
      "name": "Rohini Sanikop"
    },
    {
      "name": "Sagar Jathar"
    },
    {
      "name": "Per Sandström"
    },
    {
      "name": "Ray-Hua Horng"
    },
    {
      "name": "Jens Birch"
    },
    {
      "name": "Per Eklund"
    },
    {
      "name": "Ching-Lien Hsiao"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/db4z5048ygkxs.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.05000",
  "fulltext_url": null,
  "id": "db4z5048ygkxs",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.05000",
  "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",
      "3104|GaN-based semiconductor devices and materials"
    ]
  ],
  "openalex": "W7211882946",
  "pdf_url": "https://arxiv.org/pdf/2609.05000",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/db4z5048ygkxs.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:14Z",
      "native_id": "2609.05000",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.05000"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Local coordination, structural softening, and polarization-switching energetics in Sc-alloyed GaN",
  "title_text": "Local coordination, structural softening, and polarization-switching energetics in Sc-alloyed GaN",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:14Z",
  "url": "https://research.draconitic.com/paper/db4z5048ygkxs",
  "venue": "arXiv",
  "versions": []
}