Recording characteristics of Dy-FeCo-based magneto-optical disks in comparison to other MO materials

Abstract

The recording properties of Dy-FeCo-based magnetooptical (MO) disks were investigated for different compositions. The measurements were performed on a laser light and a magnetic field modulation recorder using a 820-nm-wavelength infrared laser. The recording results were analyzed as a function of the Curie and the compensation temperatures, T/sub C/ and T/sub comp/, respectively. The influence of the linear disk velocity on the recording characteristics, such as carrier-to-noise ratio, write/erase power, and domain stability during readout was studied. The results were compared to results for Tb-FeCo and GdTb-Fe single layer and a typical Pt/Co multilayered MO disk. Among the tested disks, Dy-FeCo with T/sub C/=490 K and T/sub comp/=370 K showed the highest write and erase sensitivity (<8 mW), the highest carrier-to-noise ratio (>or=55 dB), and the lowest difference between domain stability and erase threshold (>2 mW) up to 22 m/s disk velocity. Pt/Co showed less suitable results as its carrier-to-noise-ratio did not exceed 46 dB for ease field <or=32 kA/m and write power <or=10 mW.<<ETX>>