{
  "abstract": "We report an electron paramagnetic resonance (EPR) study of Dy${^3+}$ in CaWO$_4$ single crystals spanning dopant concentrations from 80~ppb to 247~ppm. The $g$ factors of the ground Kramers doublet at the $S_4$ point-group site, $g_\\parallel = 7.22 \\pm 0.01$ and $g_\\perp = 5.45 \\pm 0.01$, and the hyperfine constants of \\ce{^{161}Dy} and $^{163}$Dy are determined with an order-of-magnitude improvement in precision over the only previous report. A crystal-field analysis constrained jointly by published optical levels and by the measured $g$ tensor identifies the ground doublet as the lower branch of an anticrossing between the near-degenerate $\\|{\\pm}11/2>$ and $\\|{\\mp}13/2>$ states, and explains why optical data alone left the $g$ values unconstrained. \\add{The same parameter set, tested on the excited multiplets of the $^6H$ term, reproduces the ${}^6H_{13/2}$ crystal-field levels better than the optical parameters themselves.} The angular dependence of the linewidth in the $ab$ plane reveals broadening by random internal electric fields through the linear electric field effect. Calibrating these fields with the residual Er$^{3+}$ present in the same crystals yields the first electric-field coupling parameters of Dy$^3+$, $(B_{31}^2+B_{36}^2)^{1/2} = (34\\pm5)\\times10^{-6}$~cm/V, three times the Er$^{3+}$ value and the largest reported for a rare-earth ion in this host.The residual linewidth and the concentration-dependent lineshape asymmetry follow the quadratic field scaling expected for a second-order Stark shift, which escapes the inversion-site cancellation constraining the linear effect. Both couplings trace back to the $\\sim 20$~cm$^{-1}$ gap to the first opposite-symmetry doublet, a consequence of the dense crystal-field structure of the $J=15/2$ manifold.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.31208",
  "author_total": 9,
  "authors": [
    {
      "name": "Achuthan Manoj Kumar"
    },
    {
      "name": "Larissa Aboudem-Joumessi"
    },
    {
      "name": "Remy Dassonneville"
    },
    {
      "name": "Adrien Savoyant"
    },
    {
      "name": "Karolina Waszowska"
    },
    {
      "name": "Pengrui Jiao"
    },
    {
      "name": "Patrice Bertet"
    },
    {
      "name": "Philippe Goldner"
    },
    {
      "name": "Sylvain Bertaina"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6dedpg9b1hmb2.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.31208",
  "fulltext_url": null,
  "id": "6dedpg9b1hmb2",
  "issns": [],
  "landing_url": "https://hal.science/hal-05766616v1",
  "language": "en",
  "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"
    ],
    [
      "hal",
      "0.phys"
    ],
    [
      "openalex",
      "1304|Electron Spin Resonance Studies"
    ]
  ],
  "openalex": "W7214597377",
  "pdf_url": "https://arxiv.org/pdf/2609.31208",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-25",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6dedpg9b1hmb2.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:42Z",
      "native_id": "hal-05766616",
      "source": "hal",
      "url": "https://hal.science/hal-05766616v1"
    },
    {
      "first_seen": "2026-10-30T12:24:52Z",
      "native_id": "2609.31208",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.31208"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Electron paramagnetic resonance of Dy$^{3+}$-doped CaWO$_4$: spin Hamiltonian, crystal-field analysis, and linear electric field effect",
  "title_text": "Electron paramagnetic resonance of Dy^3+-doped CaWO_4: spin Hamiltonian, crystal-field analysis, and linear electric field effect",
  "type": "preprint",
  "updated_at": "2026-10-30T12:24:52Z",
  "url": "https://research.draconitic.com/paper/6dedpg9b1hmb2",
  "venue": "HAL",
  "versions": []
}