Magneto-optical recording method having constant recording sensitivity and magneto-optical recording medium used therefor
AssigneeNikon Corporation
InventorMasatoshi Sato
Life of this patent
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Abstract
A magneto-optical recording medium includes a magnetizable amorphous alloy film having a perpendicular magnetic anisotropy to the film surface. The film is formed from rare earth metals and transition metal, such that the film has a Curie point that increases as the proportion of the transition metals increases. A magneto-optical recording method includes establishing a recording magnetic field and magneto-optically recording onto the film such that even if there are compositional changes in the film, little influence on recording sensitivity results.
Claims15
A magneto-optical recording medium comprising a magnetizable amorphous alloy film having a perpendicular magnetic anisotropy to the film surface, said film comprising rare earth metals and transition metals in proportions such that a Curie point of said film increases as the proportion of the transition metals increases, wherein a variation in relative amounts of the rare earth metals and the transition metals from a predetermined proportion in said film results in little or no influence on recording sensitivity and wherein the composition of said film satisfies the formula:
- Dy.sub.x (Fe.sub.100-y Co.sub.y).sub.100-x
- wherein 26.ltoreq.x.ltoreq.29 and 15.ltoreq.y.ltoreq.25, as expressed in terms of atomic percent.
A magneto-optical recording method, comprising:
- (a) providing a magneto-optical recording medium comprising a magnetizable amorphous alloy film having a perpendicular magnetic anisotropy to the film surface, said film comprising rare earth metals and transition metals in proportions such that a Curie point of said film increases as the proportion of the transition metals increases, and wherein the composition of said film satisfies the formula:
- Dy.sub.x (Fe.sub.100-y Co.sub.y).sub.100-x
- wherein 26.ltoreq.x.ltoreq.29 and 15.ltoreq.y.ltoreq.25, as expressed in terms of atomic percent
- (b) irradiating a laser beam on said film, said laser beam modulated according to the information to be recorded on said film, and
- (c) establishing a recording magnetic field around said film;
- wherein the variation in relative amounts of the rare earth metals and the transition metals from a predetermined proportion in said film results in little or no influence on recording sensitivity.
A magneto-optical recording medium comprising a magnetizable amorphous alloy film having a perpendicular magnetic anisotropy to the film surface, said film comprising rare earth metals and transition metals in proportions such that a Curie point of said film increases as the proportion of the transition metals increases, and the composition of said film satisfies the formula:
- (Tb.sub.100-z Dy.sub.z).sub.x (Fe.sub.100-y Co.sub.y).sub.100-x
- wherein 26.ltoreq.x.ltoreq.29, 15.ltoreq.y.ltoreq.25 and 50.ltoreq.z.ltoreq.95, as expressed in terms of atomic percent and wherein a variation in relative amounts of the rare earth metals and the transition metals from a predetermined proportion in said film results in little or no change in a temperature at which the film has a predetermined coercivity.
A magneto-optical recording method, comprising:
- (a) providing a magneto-optical recording medium comprising a magnetizable amorphous alloy film having a perpendicular magnetic anisotropy to the film surface, said film comprising rare earth metals and transition metals in proportions such that a Curie point of said film increases as the proportion of the transition metals increases, wherein the composition of said film satisfies the formula:
- (Tb.sub.100-z Dy.sub.z).sub.x (Fe.sub.100-y Co.sub.y).sub.100-x
- wherein 26.ltoreq.x.ltoreq.29, 15.ltoreq.y.ltoreq.25 and 50.ltoreq.z.ltoreq.95, as expressed in terms of atomic percent;
- (b) irradiating a laser beam on said film, said laser beam modulated according to the information to be recorded on said film;
- and
- (c) establishing a recording magnetic field around said film;
- wherein the variation in relative amounts of the rare earth metals and the transition metals from a predetermined proportion in said film results in little or no influence on recording sensitivity.
Dependencies are inferred from the claim text.