MAGNETOOPTICAL APPLICATIONS OF CO/PT MULTILAYERS

Optimal preparation of a Co/Pt multilayer and a SiN underlayer achieved low disk noise and Co/Pt disks showed 6-8 dB higher carrier-to-noise ratio than TbFeCo disk at 488 nm. The disk noise originates from polarization variations which are related to [111] dispersion in the multilayer and surface roughness in the underlayer and multilayer. Exchange-coupling to TbFeCo makes the disk noise lower but simultaneously decreases the carrier. CoNi/Pt multilayers with their lower Curie temperature provide high write/erase cyclability and high write sensitivity. Recording by magnetic field modulation attained a carrier-to-noise ratio of 45 dB with a magnetic field of 16 kA/m. Co(Ni)/Pt multilayers are promising candidates for future magneto-optical recording media.