EP0349271A2
Expired / Lapsed
EP
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Magneto-optic memory device
Assignee: Sharp Corp
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Filing: 1989-06-27
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Granted: —
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Expires: 2009-06-27
Abstract
Abstract A magneto-optic memory device of reflective film structure which comprises a dielectric film (2), a magneto-optic memory film (3), a dielectric film (4) and a reflective film (5) superposed in this order on a substrate (1), the magneto-optic memory film being composed of an amorphous rare earth-transition metal alloy having the composition formula of: Dyx(FeyCo1-y)1-x wherein x is 0.20 to 0.27 and y is 0.70 to 0.90, and having a thickness of 10 to 50 nm.
Inventors
- 👤 Yasuyuki Itoh
- 👤 Takeo Takase
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 08:13
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; G11B11/10589; G11B11/10591
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
73 words
A magneto-optic memory device comprising a dielectric film, a magneto-optic memory film, a dielectric film and a reflective film superposed in this order on a substrate, the magneto-optic memory film being composed of an amorphous rare earth-transition metal alloy having the composition formula of: Dy x (Fe y Co 1-y ) 1-x wherein x is 0.20 to 0.27 an y is 0.70 to 0.90, and having a thickness of 10 to 50 nm.
Claim 2
Dependent Claim
73 words
A magneto-optic memory device comprising a dielectric film, a magneto-optic memory film, a dielectric film and a reflective film superposed in this order on a substrate, the magneto-optic memory film being composed of an amorphous rare earth-transition metal alloy having the composition formula of: Dy x (Fe y Co 1-y ) 1-x wherein x is 0.20 to 0.27 an y is 0.70 to 0.90, and having a thickness of 10 to 50 nm.
Claim 3
Dependent Claim
31 words
The magneto-optic memory device of claim 1 in which the amorphous rare-earth transition metal alloy is of the formula wherein x is 0.22 to 0.25 and y is 0.75 to 0.85.
Claim 4
Dependent Claim
21 words
The magneto-optic memory device of claim 1 in which the magneto-optic memory film has a thickness of 15 to 30 nm.
Claim 5
Dependent Claim
16 words
The magneto-optic memory device of claim 1 in which the substrate is a light transmitting substrate.
Claim 6
Dependent Claim
20 words
The magneto-optic memory device of claim 1 in which each of the dielectric films is made of a metal nitride.
Claim 7
Dependent Claim
20 words
The magneto-optic memory device of claim 5 in which the metal nitride is silicon nitride, aluminum nitride or silicon-aluminum nitride.
Claim 8
Dependent Claim
16 words
The magneto-optic memory device of claim 1 in which the reflective film is a metal film.
Claim 9
Dependent Claim
25 words
The magneto-optic memory device of claim 7 in which the metal film is made of an aluminum-nickel alloy, an aluminum-titanium alloy or an aluminum-palladium alloy.
Claim 10
Dependent Claim
25 words
The magneto-optic memory device of claim 7 in which the metal film is made of aluminum-palladium alloy containing 1 at.% to 10 at.% of palladium.
Claim 11
Dependent Claim
18 words
the magneto-optic memory device of claim 1 in the form of a magneto-optic disc or a magneto-optic card.
Claim 12
Dependent Claim
67 words
A magneto-optic memory device which includes a substrate (1) and a magneto-optic memory film (3) on said substrate, characterised in that said magneto-optic memory film (3) comprises an amorphous rare earth-transition metal alloy having the composition formula of: Dy x (Fey Co 1-y ) 1-x wherein x is 0.70 to 0.27 and y is 0.70 to 0.90, and the film thickness is from 10 to 50 nm.
Claim 13
Dependent Claim
67 words
A magneto-optic memory device which includes a substrate (1) and a magneto-optic memory film (3) on said substrate, characterised in that said magneto-optic memory film (3) comprises an amorphous rare earth-transition metal alloy having the composition formula of: Dy x (Fey Co 1-y ) 1-x wherein x is 0.70 to 0.27 and y is 0.70 to 0.90, and the film thickness is from 10 to 50 nm.
References Cited (Backward Citations)
No citation records indexed.
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