hesela.devMagnetic thermal stability factor
The magnetic thermal stability factor is the ratio of a magnetization-reversal energy barrier to thermal energy at a specified absolute temperature.
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 [1]. Delta alone is not a retention duration or an error probability.
A 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 [2]. The linked worksheet separates first reversal from opposite state at read time [3].
Relations
- related
- superparamagnetic-limit, neel-arrhenius-model, hamr, thermal-writability
Citations
- Zhou et al., Plasmonic near-field transducer for heat-assisted magnetic recording (2014), doi:10.1515/nanoph-2014-0001
- Weller and Moser, Thermal effect limits in ultrahigh-density magnetic recording (1999), doi:10.1109/20.809134
- Hesela: Magnetic retention: why 60 kBT is not an expiry date; explicit two-state worksheet, not measurements
Sources & caveats
- 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.