{
  "abstract": "Nd–Fe–B permanent magnets are essential for multiple energy, mobility, safety, and decarbonization-related technologies, yet rising demand, environmental impacts, and limited sustainable recycling options increase their material criticality. Herein, we propose Hydrogen Plasma Smelting Reduction (HPSR) as a novel composition-independent recycling strategy, applied for the first time to end-of-life (EoL) Nd–Fe–B magnets, enabling the universal treatment of mixed-quality magnetic scrap. The maximum oxygen content reduction of 66% is realized within tHPSR = 2.5 min of processing, reaching ~810 ppm while preserving the overall alloy stoichiometry, including critical rare-earth elements (REEs = Nd, Pr, and Dy). HPSRrecycled powders present higher remanent polarization (Jr = 0.54 – 0.66 T), intrinsic coercivity (Hcj = 1.02 – 1.45 T), maximum energy product (BH)max = 53.5 – 72.4 kJ m-3) and improved thermal stability, surpassing the magnetic properties of the starting scrap material without the addition of primary elements (Jr = 0.56; Hcj = 0.93 T, (BH)max = 46.5 kJ m-3). Under intentional contamination from the coating material (Ni), the reduction in the overall extrinsic magnetic properties is observed, as expected. These findings establish a foundation for the first fully sustainable and composition-independent so-called intermediate recycling loop for mixedquality REE-based magnet waste.",
  "abstract_shown": true,
  "affiliations": [
    "Circular Metallurgy and Alloy Design",
    "Max-Planck Institute for Sustainable Materials (MPI-SusMat)",
    "Department of Materials Science and Technology",
    "Nuclear and Energy Research Institute (IPEN)",
    "Fraunhofer Research Institution for Materials Recycling and Resource Strategies - Fraunhofer IWKS",
    "Department of Interface Chemistry and Surface Engineering",
    "Max-Planck-Institute for Sustainable Materials"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "name": "Rafael Gitti Tortoretto Fim",
      "orcid": "0000-0003-0972-0664"
    },
    {
      "affs": [
        0,
        1,
        2,
        3
      ],
      "name": "Melissa Röhrig Martins da Silva"
    },
    {
      "affs": [
        0,
        1,
        4
      ],
      "name": "Oliver Diehl"
    },
    {
      "affs": [
        5,
        6
      ],
      "name": "Patricia Jovičević-Klug"
    },
    {
      "affs": [
        4
      ],
      "name": "Jürgen Gassmann"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Dierk Raabe"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Matic Jovičević-Klug"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3gabg8bj20bkp.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15008192/v1",
  "fulltext_url": null,
  "id": "3gabg8bj20bkp",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008192/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",
      "2504|Magnetic Properties of Alloys"
    ]
  ],
  "openalex": "W7205016192",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15008192/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-02",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/3gabg8bj20bkp.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:17Z",
      "native_id": "10.26434/chemrxiv.15008192",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008192/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2504|Magnetic Properties of Alloys",
      "subfield": "materials-polymers"
    }
  ],
  "title": "Sustainable recycling of end-of-life Nd-Fe-B permanent magnets through hydrogen based plasma reduction",
  "title_text": "Sustainable recycling of end-of-life Nd-Fe-B permanent magnets through hydrogen based plasma reduction",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:17Z",
  "url": "https://research.draconitic.com/paper/3gabg8bj20bkp",
  "venue": "ChemRxiv",
  "versions": []
}