US4562105A
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Ferrimagnetic oxides and magneto-optical recording medium employing the same
Assignee: Ricoh Co Ltd
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Filing: 1984-03-30
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Granted: 1985-12-31
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Expires: 2004-03-30
Abstract
Abstract Ferrimagnetic oxides of the following formula, ##EQU1## wherein Me represents at least one element selected from the group consisting of Ba, Sr and Pb, M I is at least one element selected from the group consisting of Ga and Al, M II is at least one element selected from the group consisting of Bi, Gd, Tb, Dy, Ho, La, Y, Co, Zn, Ti, Sc, In, Sn, Ca, Cr, Ni and Ge, 1≦x≦8, 0<y≦6, 1≦x+y≦8, m is an ion valence of M I and n is an ion valence of M II , and a magneto-optical recording medium comprising a transparent substrate, a perpendicular magnetic-anisotropic magnetic film layer formed on the substrate, which magnetic film layer comprises one of the ferrimagnetic oxides of the above formula, and a reflection layer formed on the magnetic film layer, are disclosed.
Inventors
- 👤 Hazime Machida
- 👤 Motoharu Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:27
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70626; G11B5/70642; G11B5/70678; C; C04; C04B; C04B35/00; C04B35/01; C04B35/26; C04B35/2683; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24479; Y10T428/24521; Y10T428/24612; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/26; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
124 words
A magneto-optical recording medium comprising a transparent substrate, a perpendicular, magnetic-anisotropic, magnetic film layer formed thereon, which magnetic film layer comprises a ferrimagnetic oxide of the following formula ##EQU3## wherein Me represents at least one element selected from the group consisting of Ba, Sr and Pb, M I is at least one element selected from the group consisting of Ga and Al, M II is at least one element selected from the group consisting of Bi, Gd, Tb, Dy, Ho, La, Y, Co, Zn, Ti, Sc, In, Sn, Ca, Cr, Ni and Ge, 1≦x≦8, 0<y≦6, 1≦x+y≦8, m is an ion valence of M I and n is an ion valence of M II , and a reflection layer formed on the magnetic film layer.
Claim 2
Dependent Claim
124 words
A magneto-optical recording medium comprising a transparent substrate, a perpendicular, magnetic-anisotropic, magnetic film layer formed thereon, which magnetic film layer comprises a ferrimagnetic oxide of the following formula ##EQU3## wherein Me represents at least one element selected from the group consisting of Ba, Sr and Pb, M I is at least one element selected from the group consisting of Ga and Al, M II is at least one element selected from the group consisting of Bi, Gd, Tb, Dy, Ho, La, Y, Co, Zn, Ti, Sc, In, Sn, Ca, Cr, Ni and Ge, 1≦x≦8, 0<y≦6, 1≦x+y≦8, m is an ion valence of M I and n is an ion valence of M II , and a reflection layer formed on the magnetic film layer.
Claim 3
Dependent Claim
27 words
A magneto-optical recording medium as claimed in claim 1, wherein the thickness of said magnetic film layer is in the range of 1,000 Å to 100,000 Å.
Claim 4
Dependent Claim
32 words
A magneto-optical recording medium as claimed in claim 1, wherein said reflection layer comprises a metal or nitride selected from the group consisting of Cu, Al, Ag, Au, Pt, TiN and TaN.
Claim 5
Dependent Claim
26 words
A magneto-optical recording medium as claimed in claim 1, wherein the thickness of said reflection layer is in the range of 200 Å to 5,000 Å.
Claim 6
Dependent Claim
25 words
A magneto-optical recording medium as claim in claim 1, further comprising a transparent dielectric layer formed between said magnetic film layer and said reflection layer.
Claim 7
Dependent Claim
35 words
A magneto-optical recording medium as claimed in claim 5, wherein said transparent dielectric layer comprises an oxide selected from the group consisting of SiO 2 , SiO, TiO 2 , TiO and CeO 2 .
Claim 8
Dependent Claim
33 words
A magneto-optical recording medium as claimed in claim 1 in which said magnetic film layer is a vapor-deposited film layer which has been formed on said substrate by evaporation, sputtering or ion plating.
Claim 9
Dependent Claim
28 words
A magneto-optical recording medium as claimed in claim 1, further comprising a protective layer for protecting said reflection layer, which protective layer is formed on said reflection layer.
Claim 10
Dependent Claim
33 words
A magneto-optical recording medium as claimed in claim 8, wherein said protective layer comprises a material selected from the group consisting of TiN, Si 3 N 4 , TaN, SiO 2 and SiO.
Claim 11
Dependent Claim
45 words
A magneto-optical recording medium as claimed in claim 1, further comprising a guide layer having guide grooves for guiding the application of laser beams at the time of recording and reproduction, which guide layer is interposed between said magnetic film layer and said reflection layer.
Claim 12
Dependent Claim
28 words
A magneto-optical recording medium as claimed in claim 10, further comprising a protective layer for protecting said reflection layer, which protective layer is formed on said reflection layer.
Claim 13
Dependent Claim
159 words
A magneto-optical recording medium comprising a transparent substrate, a vapor-deposited, perpendicular, magnetic-anisotropic, magnetic film layer formed thereon by evaporation or sputtering, which magnetic film layer has a thickness in the range of 1000 Å to 100,000 Å and consists of a ferrimagnetic oxide of the following formula ##EQU4## wherein Me represents at least one element selected from the group consisting of Ba, Sr and Pb, M I is at least one element selected from the group consisting of Ga and Al, M II is at least one element selected from the group consisting of Bi, Gd, Tb, Dy, Ho, La, Y, Co, Zn, Ti, Sc, In, Sn, Ca, Cr, Ni and Ge, 1≦x≦8, 0<y≦6, 1≦x+y≦8, m is an ion valence of M I and n is an ion valence of M II , and a reflection layer formed on the magnetic film layer, said reflection layer having a thickness in the range of from 200 Å to 5000 Å.
Claim 14
Dependent Claim
159 words
A magneto-optical recording medium comprising a transparent substrate, a vapor-deposited, perpendicular, magnetic-anisotropic, magnetic film layer formed thereon by evaporation or sputtering, which magnetic film layer has a thickness in the range of 1000 Å to 100,000 Å and consists of a ferrimagnetic oxide of the following formula ##EQU4## wherein Me represents at least one element selected from the group consisting of Ba, Sr and Pb, M I is at least one element selected from the group consisting of Ga and Al, M II is at least one element selected from the group consisting of Bi, Gd, Tb, Dy, Ho, La, Y, Co, Zn, Ti, Sc, In, Sn, Ca, Cr, Ni and Ge, 1≦x≦8, 0<y≦6, 1≦x+y≦8, m is an ion valence of M I and n is an ion valence of M II , and a reflection layer formed on the magnetic film layer, said reflection layer having a thickness in the range of from 200 Å to 5000 Å.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1988-12-30 | 1989-07-01 | 1989-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-30 | 1993-07-01 | 1993-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-30 | 1997-07-01 | 1997-12-31 | $7700.00 | Window Closed / Lapsed |