{
  "abstract": "The simultaneous suppression of lattice heat transport and enhancement of carrier transport is central to the development of high-performance thermoelectric materials. Here, we investigate the microscopic mechanisms governing phonon and carrier transport in CaAl$_2$Si$_2$-type AMg$_2$X$_2$ (A = Ca, Sr, Ba; X = P, As, Sb, Bi) Zintl compounds using first-principles calculations, machine-learning interatomic potentials, and Boltzmann transport theory. As X changes from P to Bi, the widening phonon band gap restricts three-phonon scattering channels and increases the relative importance of four-phonon processes. In CaMg$_2$Bi$_2$ and BaMg$_2$Bi$_2$, four-phonon scattering dominates the relaxation of low-frequency heat-carrying modes at 900 K. The Bi-based series also exhibits an anomalous increase in lattice thermal conductivity from Ca to Ba despite the increasing cation mass. Mode-resolved analysis links the lower thermal conductivity of CaMg$_2$Bi$_2$ to reduced low-frequency group velocities and stronger anharmonic scattering, with Ca-related mid-frequency vibrations providing additional four-phonon scattering channels. Including both particle-like and coherent contributions, its lattice thermal conductivity reaches 0.23 W$\\cdot$m$^{-1}$K$^{-1}$ at 900 K. Meanwhile, the increasing covalent character of the vertical Mg-X bonds is accompanied by enhanced band-edge dispersion and reduced carrier effective masses. These electronic changes, together with conduction-band convergence, favor n-type transport and yield a predicted peak $ZT$ of 3.68 at 900 K in CaMg$_2$Bi$_2$. These results elucidate the interplay of phonon spectral structure and higher-order anharmonicity in thermal transport, alongside the distinct electronic response to anion substitution.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.02961",
  "author_total": 9,
  "authors": [
    {
      "name": "Ning Wang"
    },
    {
      "name": "Jincheng Yue"
    },
    {
      "name": "Hui Zhang"
    },
    {
      "name": "Xingchen Shen"
    },
    {
      "name": "Wenling Ren"
    },
    {
      "name": "Shuyao Lin"
    },
    {
      "name": "Yanhui Liu"
    },
    {
      "name": "Yue-Wen Fang"
    },
    {
      "name": "Tian Cui"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8ss9g9n5met11.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.02961",
  "fulltext_url": null,
  "id": "8ss9g9n5met11",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.02961",
  "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": null,
  "pdf_url": "https://arxiv.org/pdf/2611.02961",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-02",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/8ss9g9n5met11.ris",
  "sources": [
    {
      "first_seen": "2026-11-03T12:20:59Z",
      "native_id": "2611.02961",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.02961"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Anion Engineering Enables Concurrent Optimization of Phonon and Carrier Transport in AMg$_2$X$_2$ Zintl Thermoelectrics",
  "title_text": "Anion Engineering Enables Concurrent Optimization of Phonon and Carrier Transport in AMg_2X_2 Zintl Thermoelectrics",
  "type": "preprint",
  "updated_at": "2026-11-05T15:20:18Z",
  "url": "https://research.draconitic.com/paper/8ss9g9n5met11",
  "venue": "arXiv",
  "versions": []
}