Temperature dependence of the stability of written bits in a magnetic hard-disk medium investigated by magnetic force microscopy

Abstract The thermal stability of written bits in a magnetic hard-disk medium has been investigated with a magnetic force microscope (MFM), which was equipped with an in situ heating system capable of heating the medium up to 300 °C. It is shown that both the annealing temperature and the duration have significant effect on the decay of the MFM signal. No signal decay is observed when annealing for 30 min up to temperatures of 200 °C. The MFM signal decays rapidly with increasing temperature, for temperatures over 200 °C. Repeated annealing at 280 °C with a duration below 10 min does not cause any signal decay.