{
  "abstract": "The $α$, $δ$, and $β$ phases of PVDF are interconverted by electrical poling and mechanical drawing, yet the thermodynamics under a controlled electrical boundary condition has not been established from first principles. We evaluate the zero-temperature free energy at fixed electric displacement $D$ from van der Waals density-functional calculations along two constrained coordinates in a common 24-atom cell: a tilt of the gauche C--C bonds that maps antipolar $α$ onto polar $δ$ (cell change $<1\\%$), and a backbone torsion that straightens TG$^+$TG$^-$ chains into all-trans $β$ (chain-repeat strain $10.6\\%$). As $D$ increases from 0 to $0.30$~C\\,m$^{-2}$, the lowest homogeneous free energy switches from $α$ to $δ$ at $D_{c1}=0.046$~C\\,m$^{-2}$ and from $δ$ to $β$ at $D_{c2}=0.157$~C\\,m$^{-2}$. At $T=0$ with domain-wall energy neglected, a $δ$ multidomain state lies $14.3$~meV per cell below homogeneous $α$ at every $D$. A $Γ$-point harmonic estimate suggests that vibrations reverse this ordering at room temperature. $δ$ and $β$ coexist for $0.11<D<0.21$~C\\,m$^{-2}$ at $E^*=0.69$~GV\\,m$^{-1}$, independent of the screening constant. The tilt barrier falls from $0.66$~eV per cell at $D=0$ to $17$~meV at $D=0.30$~C\\,m$^{-2}$ (below $k_BT$ at $300$~K), while the torsion barrier remains $0.66$~eV at $D_{c2}$ and $0.34$~eV at $D=0.30$~C\\,m$^{-2}$, so $δ\\toβ$ stays first order. Much of the difference traces to the path effective charge ($0.28e$ for the tilt, $0.18e$ for the torsion). Scaling shows the tilt barrier would survive with the torsion charge; the smaller torsion charge accounts for about half the barrier it retains. The landscape accounts for why a field produces $δ$ and why $β$ is reached by drawing, and suggests that raising that charge could let a field alone produce $β$.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.31926",
  "author_total": 5,
  "authors": [
    {
      "name": "Shaohui Qiu"
    },
    {
      "name": "Jacob C. Dean"
    },
    {
      "name": "Rajagopalan Thiruvengadathan"
    },
    {
      "name": "Ramanujam Brahmadesam Thoopul Srinivasa Raghava"
    },
    {
      "name": "Yiming Su"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4k4evcmxm2whn.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.31926",
  "fulltext_url": null,
  "id": "4k4evcmxm2whn",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.31926",
  "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",
      "2204|Dielectric materials and actuators"
    ]
  ],
  "openalex": "W7223678442",
  "pdf_url": "https://arxiv.org/pdf/2610.31926",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-26",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4k4evcmxm2whn.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:35Z",
      "native_id": "2610.31926",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.31926"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Poly(vinylidene fluoride) under finite electric displacement fields: a removable $α\\!\\to\\!δ$ reorientation barrier and a persistent first-order $δ\\!\\to\\!β$ conformational change",
  "title_text": "Poly(vinylidene fluoride) under finite electric displacement fields: a removable α → δ reorientation barrier and a persistent first-order δ → β conformational change",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:35Z",
  "url": "https://research.draconitic.com/paper/4k4evcmxm2whn",
  "venue": "arXiv",
  "versions": []
}