Stability of magnetooptical disks under the action of external magnetic fields

The stability of data recorded on magnetooptical disks of different manufacturers is investigated under external magnetic fields oriented along the normal to the disk surface. The recorded data are found to be damaged under magnetic fields with intensities ranging from 300 to 350 kA/m. However, such disks can be reused for information recording. Under the action of magnetic fields with intensities more than 420 kA/m, information on disks is lost and they cannot be reused.