{
  "status": "research",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-16",
  "slug": "thermal-writability",
  "term": "Thermal writability",
  "aliases": [],
  "definition": "Thermal writability is the requirement that a magnetic write field bias the intended state strongly enough relative to thermal fluctuations to meet a recording-error target.",
  "note": "Evans and colleagues distinguish this from merely overcoming coercivity [evans-thermal-writability]. Their equilibrium, aligned-axis model describes a single grain per bit; numerical density estimates depend on write field, temperature, magnetization and error tolerance. They are not universal commercial-HAMR limits. This concerns errors during writing, not only retention after cooling.",
  "related": [
    "hamr",
    "superparamagnetic-limit",
    "near-field-transducer"
  ],
  "citations": [
    {
      "id": "evans-thermal-writability",
      "title": "Evans, Chantrell, Nowak, Lyberatos and Richter: Thermally induced error: density limit for magnetic data storage (2012), doi:10.1063/1.3691196; equations 1-2 and concluding limitations; arXiv v2",
      "url": "https://arxiv.org/html/1111.0524v2",
      "accessed": "2026-10-16"
    }
  ]
}