READ WRITE CHARACTERISTICS OF MNBI MAGNETOOPTICAL DISK FABRICATED ON PHOTO-POLYMER SUBSTRATE

A quadrilayer MnBi magneto-optical disk on a photo-polymer (2P) substr ate has been fabricated by a low-temperature growth method. Magneto-op tical properties and read/write characteristics for the 2P MnBi disk a re confirmed to be comparable to those of a glass MnBi disk annealed a t 380 degrees C. The carrier to noise (C/N) ratio for the 2P MnBi disk is 20 dB lower than that of a conventional TbFeCo disk because of its high disk noise. While the Kerr rotation angle at the flat area of th e MnBi disk is three times that for a TbFeCo disk, the carrier level i s about 1 dB lower. Controlling the Bi layer morphology in the groove area will be the most important factor in achieving future improvement of the C/N ratio for MnBi magneto-optical disks.