Read/Write Characteristics of MnBi Magneto-Optical Disk Fabricated on Photo-Polymer Substrate

A quadrilayer MnBi magneto-optical disk on a photo-polymer (2P) substrate has been fabricated by a low-temperature growth method. Magneto-optical properties and read/write characteristics for the 2P MnBi disk are confirmed to be comparable to those of a glass MnBi disk annealed at 380° 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 the MnBi disk is three times that for a TbFeCo disk, the carrier level is 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.