{
  "aliases": [],
  "status": "research",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-17",
  "slug": "magnetic-thermal-stability-factor",
  "term": "Magnetic thermal stability factor",
  "definition": "The magnetic thermal stability factor is the ratio of a magnetization-reversal energy barrier to thermal energy at a specified absolute temperature.",
  "note": "Write Delta = E_b/(k_B T), where E_b is in joules and T in kelvin; the simple uniaxial zero-effective-field picture gives E_b = K_u V [zhou]. Delta alone is not a retention duration or an error probability.\n\nA retention calculation also needs an attempt-rate convention, observation interval, event definition and barrier distribution. The often cited value near 60 is context dependent, not a universal pass/fail threshold [weller]. The linked worksheet separates first reversal from opposite state at read time [hesela-retention].",
  "related": [
    "superparamagnetic-limit",
    "neel-arrhenius-model",
    "hamr",
    "thermal-writability"
  ],
  "provenance": [
    "Dimensionless physical/model quantity, not a commercial product specification.",
    "Weller/Moser used only at institutional-abstract scope; numerical examples in the related analysis are hypothetical."
  ],
  "citations": [
    {
      "id": "zhou",
      "title": "Zhou et al., Plasmonic near-field transducer for heat-assisted magnetic recording (2014), doi:10.1515/nanoph-2014-0001",
      "url": "https://engineering.purdue.edu/NanoLab/publications/PDF/2014-Plasmonic-near-field-transducer-for-heat-assisted-magnetic-recording.pdf",
      "accessed": "2026-10-17"
    },
    {
      "id": "weller",
      "title": "Weller and Moser, Thermal effect limits in ultrahigh-density magnetic recording (1999), doi:10.1109/20.809134",
      "url": "https://research.ibm.com/publications/thermal-effect-limits-in-ultrahigh-density-magnetic-recording",
      "accessed": "2026-10-17"
    },
    {
      "id": "hesela-retention",
      "title": "Hesela: Magnetic retention: why 60 kBT is not an expiry date; explicit two-state worksheet, not measurements",
      "url": "https://hesela.com/analyses/magnetic-retention-time-and-probability/",
      "accessed": "2026-10-17"
    }
  ]
}