Magnetooptical recording medium
AssigneeCanon Kabushiki Kaisha
InventorsHiroyoshi Kishi, Masaaki Matsushima
Life of this patent
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Abstract
A magnetooptical recording medium of an amorphous magnetic alloy film of a composition which as an axis of easy magnetization in a direction perpendicular to the film surface represented by I, II or III: [(GdTb).sub.1-y (FeCo).sub.y ].sub.1-p Cr.sub.p (I) wherein 0.5.ltoreq.y.ltoreq.0.9 and 0.001.ltoreq.p.ltoreq.0.3; (GdTbFe).sub.1-(p+q) Cr.sub.p X.sub.q (II) wherein X can be either silicon or aluminum; p.gtoreq.0.001, q.gtoreq.0.001 and (p+q).ltoreq.0.3; or [(GdTb).sub.1-y (FeCo).sub.y ].sub.1-(p+q) Cr.sub.p X.sub.q (III) wherein X can be either silicon or aluminum, 0.5.ltoreq.y.ltoreq.0.9, p>0.001, q.gtoreq.0.001 and (p+q).ltoreq.0.3.
Claims5
A magnetooptical recording medium which comprises an amorphous magnetic alloy film having an axis of easy magnetization in a direction perpendicular to the film surface, said alloy having a composition represented by the general formula IV as follows:
- [(Gd.sub.1-z Tb.sub.z).sub.1-y (Fe.sub.1-x Co.sub.x).sub.y ].sub.1-p Cr.sub.p (IV)
- wherein 0<z<1;
- 0.005.ltoreq.x<1;
- 0.5.ltoreq.y.ltoreq.0.9 and 0.001.ltoreq.p.ltoreq.0.3.
A magnetooptical recording medium which comprises an amorphous magnetooptical alloy film having an axis of easy magnetization in a direction perpendicular to the film surface, said alloy having a composition represented by the general formula II as follows:
- (GdTbFe).sub.1-(p+q) Cr.sub.p Si.sub.q (II)
- wherein p.gtoreq.0.001, q.gtoreq.0.001 and (p+q).ltoreq.0.3.
A magnetooptical recording medium which comprises an amorphous magnetooptical alloy film having an axis of easy magnetization in a direction perpendicular to the film surface, said alloy having a composition represented by the general formula III as follows:
- [(GdTb).sub.1-y (FeCo).sub.y ].sub.1-(p+q) Cr.sub.p Si.sub.q
- wherein 0.5.ltoreq.y.ltoreq.0.9, p.gtoreq.0.001, q.gtoreq.0.001 and (p+q).ltoreq.0.3.
A magnetooptical recording medium which comprises an amorphous mgnetooptical alloy film having an axis of easy magnetication in a direction perpendicular to the film surface, said alloy having a composition represented by the general formula II as follows:
- (GdTbFe).sub.1-(p+q) Cr.sub.p Al.sub.q (II)
- wherein p.gtoreq.0.001, q.gtoreq.0.001 and (p+q).ltoreq.0.3.
A magnetooptical recording medium which comprises an amorphous magnetooptical alloy film having an axis of easy magnetization in a direction perpendicular to the film surface, said alloy having a composition represented by the general formula III as follows:
- [(GdTb.sub.1-y (FeCo).sub.y ].sub.1-(p+q) Cr.sub.p Al.sub.q (III)
- wherein 0.5.ltoreq.y.ltoreq.0.9, p.gtoreq.0.001, q.gtoreq.0.001 and (p+q).ltoreq.0.3.
Dependencies are inferred from the claim text.