Magneto-optical recording on amorphous rare earth-transition metal thin films with an artificially layered structure

Amorphous rare earth (Cd, Tb and Dy)-transition metal (Fe, Co and FeCo alloy) thin films with an artificially layered structure have been investigated. The films were deposited in an alternating multi-layer structure by the multi-source DC-sputtering method. Films with a repeat unit composed of a monatomic layer of RE and a few atomic layers of TM show excellent magnetic properties when considered as magnetooptical recording media, such as a large magnetization and perpendicular magnetic anisotropy. RE-FeCo and RE-CoFe films used in magnetooptical recording showed carrier-to-noise ratios higher than 52 db, and Dy-FeCo films showed a high carrier-to-noise ratio over a wide frequency range that extended from 57 dB at 1 MHz to 38 db at 10 MHz.