{
  "abstract": "Metal-mediated growth provides an effective route to high-quality hexagonal boron nitride (hBN), but hBN formation on the metal does not necessarily ensure hBN formation on an adjoining dielectric substrate. Here, we investigate this distinction using a vertically stacked Ni--Cr/boron/sapphire configuration operated at 1550~$^\\circ$C under atmospheric pressure, with the relative boron supply varied at fixed Ni:Cr = 8:2. hBN is detected by Raman spectroscopy on the gas-exposed alloy surface throughout the investigated Alloy:B range, whereas sapphire-side hBN appears only at the higher relative boron supplies of Alloy:B = 24:1 and 18:1, as confirmed by both Raman spectroscopy and XRD. The hBN (002) reflection further narrows as the boron supply increases from 24:1 to 18:1, corresponding to an increase in the apparent c-axis coherent length from approximately 86 to 143~nm. Additional crystalline reflections also emerge only under these higher-boron conditions. These results identify boron supply as a key parameter governing the transition from alloy-side hBN formation to concurrent sapphire-side hBN growth. Once formed, sapphire-side hBN occurs within a substantially reconstructed and chemically modified Al/O-rich sapphire environment rather than as a uniform film on an intact substrate. To our knowledge, this study provides the first demonstration of successful sapphire-side hBN formation by Ni--Cr-mediated growth.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.23447",
  "author_total": 5,
  "authors": [
    {
      "name": "Donghoi Kim"
    },
    {
      "name": "Aelim Ha"
    },
    {
      "name": "Soohyung Park"
    },
    {
      "name": "Young Duck Kim"
    },
    {
      "name": "Chinkyo Kim"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7a3b3m29kh21p.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.23447",
  "fulltext_url": null,
  "id": "7a3b3m29kh21p",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.23447",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.mtrl-sci"
    ],
    [
      "openalex",
      "2505|Boron and Carbon Nanomaterials Research"
    ]
  ],
  "openalex": "W7214053111",
  "pdf_url": "https://arxiv.org/pdf/2609.23447",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-20",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/7a3b3m29kh21p.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:19Z",
      "native_id": "2609.23447",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.23447"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Sapphire-Side hBN Formation by Ni--Cr-Mediated Growth in a Stacked Ni--Cr/Boron/Sapphire Configuration: Effect of Boron Supply",
  "title_text": "Sapphire-Side hBN Formation by Ni--Cr-Mediated Growth in a Stacked Ni--Cr/Boron/Sapphire Configuration: Effect of Boron Supply",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:19Z",
  "url": "https://research.draconitic.com/paper/7a3b3m29kh21p",
  "venue": "arXiv",
  "versions": []
}