US4978584A
Expired / Lapsed
US
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Magneto-optical storage medium
Assignee: Siemens AG
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Filing: 1989-05-05
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Granted: 1990-12-18
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Expires: 2009-05-05
Abstract
Abstract A storage medium comprising a multilayer system with at least one magnetic layer, of magneto-optical storage material, and at least one reflector layer, with an index of refraction n<1, which is at least as thick as one of the magnetic layers. The maximum thickness of each of the magnetic layers is inversely proportional to its absorption coefficient, K. In the magneto-optical multilayer system of the present invention, a large Kerr angle O K is obtained.
Inventors
- 👤 Wolfgang Reim
- 👤 Dieter Weller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:58
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/12493; Y10T428/12535; Y10T428/12576; Y10T428/12632; Y10T428/12771; Y10T428/12861; Y10T428/12889; Y10T428/12896
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
102 words
Magneto-optical storage medium of several layers with different magnetic properties, comprising: at least one magnetic layer of a magnetic storage material; at least one reflector layer with an index of refraction, n, less than one; wherein the thickness of the reflector layer is at least as large as the thickness of the magnetic layer, and the maximum thickness of the magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer, and wherein the reflector layer is selected from the group consisting of silver, Ag; thulium sulfide, Tms; titanium nitride, TiN; zirconium nitride, ZrN; hafnium nitride, HfN; gold, Au.
Claim 2
Dependent Claim
102 words
Magneto-optical storage medium of several layers with different magnetic properties, comprising: at least one magnetic layer of a magnetic storage material; at least one reflector layer with an index of refraction, n, less than one; wherein the thickness of the reflector layer is at least as large as the thickness of the magnetic layer, and the maximum thickness of the magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer, and wherein the reflector layer is selected from the group consisting of silver, Ag; thulium sulfide, Tms; titanium nitride, TiN; zirconium nitride, ZrN; hafnium nitride, HfN; gold, Au.
Claim 3
Dependent Claim
23 words
The storage medium of claim 1 wherein the thickness of the reflector layer is at least twice the thickness of the magnetic layer.
Claim 4
Dependent Claim
33 words
The storage medium of claim 1 comprising: a plurality of said magnetic layers, arranged with a plurality of said reflector layers, wherein each magnetic layer is separated by one of the reflector layers.
Claim 5
Dependent Claim
39 words
The storage medium of claim 2 wherein each magnetic layer has the same thickness, and each reflector layer has the same thickness, and the thickness of each reflector layer is at least twice the thickness of each magnetic layer.
Claim 6
Dependent Claim
38 words
The storage medium according of claim 2 wherein the plurality of the magnetic layers and the plurality of the reflector layers have a total thickness greater than three divided by the absorption coefficient, K, of the storage medium.
Claim 7
Dependent Claim
13 words
The storage medium of claim 2 wherein the magnetic layers comprise terbium-iron-cobalt, TbFeCo.
Claim 8
Dependent Claim
14 words
The storage medium of claim 2 wherein the magnetic layers comprise of ytterbium-terbium-iron-cobalt, YbTbFeCo.
Claim 9
Dependent Claim
13 words
The storage medium of claim 2 wherein the magnetic layers comprise gadolinium-terbium-iron-cobalt, GdTbFeCo.
Claim 10
Dependent Claim
15 words
The storage medium of claim 8, wherein at least one reflector layer comprises gold, Au.
Claim 11
Dependent Claim
15 words
The storage medium of claim 2 wherein at least one reflector layer comprises silver Ag.
Claim 12
Dependent Claim
17 words
The storage medium of the claim 2 wherein at least one reflector layer comprises thulium sulfide, TmS.
Claim 13
Dependent Claim
16 words
The storage medium of claim 2 wherein at least one reflector layer comprises titanium nitride, TiN.
Claim 14
Dependent Claim
16 words
The storage medium of claim 2 wherein at least one reflector layer comprises zirconium nitride, ZrN.
Claim 15
Dependent Claim
16 words
The storage medium of claim 2 wherein at least one reflector layer comprises hafnium nitride, HfN.
Claim 16
Dependent Claim
99 words
A magneto-optical storage medium of several layers with different magnetic properties, comprising: a plurality of magnetic layers of a magnetic storage material arranged with; a plurality of reflector layers with an index of refraction, n, less than one; wherein the thickness of each reflector layer is at least as large as the thickness of each magnetic layer and the maximum thickness of each magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer; and wherein each magnetic layer is separated by one of the reflector layers and at least on reflector layer comprises silver, Ag.
Claim 17
Dependent Claim
99 words
A magneto-optical storage medium of several layers with different magnetic properties, comprising: a plurality of magnetic layers of a magnetic storage material arranged with; a plurality of reflector layers with an index of refraction, n, less than one; wherein the thickness of each reflector layer is at least as large as the thickness of each magnetic layer and the maximum thickness of each magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer; and wherein each magnetic layer is separated by one of the reflector layers and at least on reflector layer comprises silver, Ag.
Claim 18
Dependent Claim
100 words
A magneto-optical storage medium of several layers with different magnetic properties, comprising: a plurality of magnetic layers of a magnetic storage material arranged with; a plurality of reflector layers with an index of refraction, n, less than one; wherein the thickness of each reflector layer is at least as large as the thickness of each magnetic layer and the maximum thickness of each magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer; and wherein each magnetic layer is separated by one of the reflector layers and at least on reflector layer comprises thulium sulfide, TmS.
Claim 19
Dependent Claim
100 words
A magneto-optical storage medium of several layers with different magnetic properties, comprising: a plurality of magnetic layers of a magnetic storage material arranged with; a plurality of reflector layers with an index of refraction, n, less than one; wherein the thickness of each reflector layer is at least as large as the thickness of each magnetic layer and the maximum thickness of each magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer; and wherein each magnetic layer is separated by one of the reflector layers and at least on reflector layer comprises thulium sulfide, TmS.
Claim 20
Dependent Claim
100 words
A magneto-optical storage medium of several layers with different magnetic properties, comprising: a plurality of magnetic layers of a magnetic storage material arranged with; a plurality of reflector layers with an index of refraction, n, less than one; wherein the thickness of each reflector layer is at least as large as the thickness of each magnetic layer and the maximum thickness of each magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer; and wherein each magnetic layer is separated by one of the reflector layers and at least one reflector layer comprises titanium nitride, TiN.
Claim 21
Dependent Claim
100 words
A magneto-optical storage medium of several layers with different magnetic properties, comprising: a plurality of magnetic layers of a magnetic storage material arranged with; a plurality of reflector layers with an index of refraction, n, less than one; wherein the thickness of each reflector layer is at least as large as the thickness of each magnetic layer and the maximum thickness of each magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer; and wherein each magnetic layer is separated by one of the reflector layers and at least one reflector layer comprises titanium nitride, TiN.
Claim 22
Dependent Claim
100 words
A magneto-optical storage medium of several layers with different magnetic properties, comprising: a plurality of magnetic layers of a magnetic storage material arranged with; a plurality of reflector layers with an index of refraction, n, less than one; wherein the thickness of each reflector layer is at least as large as the thickness of each magnetic layer and the maximum thickness of each magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer; and wherein each magnetic layer is separated by one of the reflector layers and at least one reflector layer comprises zirconium nitride, ZrN.
Claim 23
Dependent Claim
100 words
A magneto-optical storage medium of several layers with different magnetic properties, comprising: a plurality of magnetic layers of a magnetic storage material arranged with; a plurality of reflector layers with an index of refraction, n, less than one; wherein the thickness of each reflector layer is at least as large as the thickness of each magnetic layer and the maximum thickness of each magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer; and wherein each magnetic layer is separated by one of the reflector layers and at least one reflector layer comprises zirconium nitride, ZrN.
Claim 24
Dependent Claim
100 words
A magneto-optical storage medium of several layers with different magnetic properties, comprising: a plurality of magnetic layers of a magnetic storage material arranged with; a plurality of reflector layers with an index of refraction, n, less than one; wherein the thickness of each reflector layer is at least as large as the thickness of each magnetic layer and the maximum thickness of each magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer; and wherein each magnetic layer is separated by one of the reflector layers and at least one reflector layer comprises hafnium nitride, HfN.
Claim 25
Dependent Claim
100 words
A magneto-optical storage medium of several layers with different magnetic properties, comprising: a plurality of magnetic layers of a magnetic storage material arranged with; a plurality of reflector layers with an index of refraction, n, less than one; wherein the thickness of each reflector layer is at least as large as the thickness of each magnetic layer and the maximum thickness of each magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer; and wherein each magnetic layer is separated by one of the reflector layers and at least one reflector layer comprises hafnium nitride, HfN.
Claim 26
Dependent Claim
99 words
A magneto-optical storage medium of several layers with different magnetic properties, comprising: a plurality of magnetic layers of a magnetic storage material arranged with; a plurality of reflector layers with an index of refraction, n, less than one; wherein the thickness of each reflector layer is at least as large as the thickness of each magnetic layer and the maximum thickness of each magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer; and wherein each magnetic layer is separated by one of the reflector layers and at least one reflector layer comprises gold, Au.
Claim 27
Dependent Claim
99 words
A magneto-optical storage medium of several layers with different magnetic properties, comprising: a plurality of magnetic layers of a magnetic storage material arranged with; a plurality of reflector layers with an index of refraction, n, less than one; wherein the thickness of each reflector layer is at least as large as the thickness of each magnetic layer and the maximum thickness of each magnetic layer equals 1/K, where K is the absorption coefficient of the magnetic layer; and wherein each magnetic layer is separated by one of the reflector layers and at least one reflector layer comprises gold, Au.
References Cited (Backward Citations)
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