MAGNETO-OPTIC RECORDING MEDIUM AND METHOD OF ITS MANUFACTURE METHOD

摘要

A recording medium for magnetic field modulation recording by which the recording can be done with the weakest possible demodulating field. On a transparent substrate (11), a first dielectric layer (12), a recording layer (13), a recording auxiliary layer (14), a second dielectric layer, and a reflecting layer (16) are formed. The recording layer is made of a transition metal-rare earth metal amorphous alloy, and usually has a thickness of hundreds Angstroms. The recording auxiliary layer (14) is also made of a transition metal-rare earth metal amorphous alloy, but its Curie temperature Tc2 is 10K higher than the Curie temperature Tc1 of the recording layer (13). The layer (14) is as thin as 70 Angstroms or less. The aspect ratio of the recording auxiliary layer (14) is 0.7 or more at the Curie temperature Tc1 of the recording layer (13). These required characteristics of the recording auxiliary layer (14) can be materialized by adjusting the composition of the recording auxiliary layer (14) and reducing its density. As another materials for the recording auxiliary layer (14), a transition metal such as Fe, Co, a non-magnetic metal such as Pt, Al, Ti, Cr, or a nitride of transition metal-rare earth metal amorphous alloy. This medium is particularly suitable for a small-sized magneto-optic disc.