Patent ID: 6096446
Filing Date: 2000-08-01
Classification: G11B,Y10S,Y10T

Abstract:
A magnetooptical recording medium, comprising:a (R-TM) thin film, where R is a rare earth element of 15 to 50 atomic % and TM is an iron group transition metal; at least 70% of R being at least one of Tb and Dy and the remainder of R being at least one element selected from the group consisting of Y, La, Ce, Sm, Gd, Tb, Dy, Ho, Er, and Yb; and said TM being at least one of Fe and Co; the content of said Fe ranging from 0 to 100%; whereinsaid magnetooptical recording medium has a vertical magnetic anisotropic constant Ku larger than a demagnetizing field energy of 2.pi.Ms.sup.2 (where Ms is a saturated magnetization), and a FOM (Figure of Merit)=R.sqroot. [.theta..sub.k.sup.2 +.eta..sub.k.sup.2 ] equal to or greater than 0.05 in a range of ultraviolet radiation of a wavelength of 400 nm or less, where .theta..sub.k is a Kerr rotation angle and .eta..sub.k is a Kerr ellipticity.