Thermal stability of written bits in high density magneto-optical recording media

Masurements of magnetic domains in TbFeCo films currently used as magneto-optical recording media indicate a shrinkage in domain size under accelerated conditions. A criterion factor (E/sub a//kT) for thermal stability is found to be about 40 for domains with a diameter of about 0.8 /spl mu/m, where E/sub a/ is an activation energy estimated on the basis of Arrenhius plot of the shrinkage with time. For high density recording applications, a higher wall pinning field is necessary.