Patent US4438962A successfully refreshed from Google Patents.
US5116693A
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Unique system of FE/PD for magneto-optical recording and magnetic switching devices
Assignee: United States Department of Energy
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Filing: 1990-05-22
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Granted: 1992-05-26
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Expires: 2010-05-22
Abstract
Abstract A high density magneto-optical information storage medium utilizing the properties of an ultrathin iron film on a palladium substrate. The present invention comprises a magneto-optical medium capable of thermal and magnetic stability and capable of possessing a vertical orientation of the magnetization vector for the magnetic material. Data storage relies on the temperature dependence of the coercivity of the ultrathin film. Data retrieval derives from the Kerr effect which describes the direction of rotation of a plane of polarized light traversing the ultrathin magnetic material as a function of the orientation of the magnetization vector.
Inventors
- 👤 Chian Q. Liu
- 👤 Samuel D. Bader
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:09
CPC Classifications
C; C30; C30B; C30B23/00; C30B23/02; B; B82; B82Y; B82Y25/00; B82Y40/00; C30B29/00; C30B29/02; G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; H; H01; H01F; H01F10/00; H01F10/32; H01F10/324; H01F10/3286; H01F41/00; H01F41/14; H01F41/30; H01F41/301; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12903; Y10T428/12917
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
49 words
A magneto-optical information storage medium comprising: a palladium substrate; an ultrathin iron film epitaxially deposited on said palladium substrate where said ultrathin iron film has a thickness of less than 2.5 monolayers and has an easy axis of magnetization oriented perpendicular to the plane of said ultrathin iron film.
Claim 2
Dependent Claim
49 words
A magneto-optical information storage medium comprising: a palladium substrate; an ultrathin iron film epitaxially deposited on said palladium substrate where said ultrathin iron film has a thickness of less than 2.5 monolayers and has an easy axis of magnetization oriented perpendicular to the plane of said ultrathin iron film.
Claim 3
Independent Claim
43 words
The method of employing a ultrahigh vacuum, molecular beam epitaxy deposition technique to produce a ultrathin iron film on a palladium substrate where the thickness of said ultrathin iron film is determined by a layer on layer depositional growth using said epitaxial technique.
Claim 4
Independent Claim
43 words
The method of employing a ultrahigh vacuum, molecular beam epitaxy deposition technique to produce a ultrathin iron film on a palladium substrate where the thickness of said ultrathin iron film is determined by a layer on layer depositional growth using said epitaxial technique.
Claim 5
Dependent Claim
17 words
The medium of claim 1 where said ultrathin iron film has a vertical easy axis of magnetization.
Claim 6
Dependent Claim
30 words
The medium of claim 1 where cycling the medium over a range of temperature to include exceeding a transition temperature does not change the magnetic hysteresis properties of the medium.
Claim 7
Dependent Claim
34 words
The medium of claim 1 where the shape of a hysteresis loop associated with said medium is approximately rectangular and experiences no significant change subsequent to a thermal cycling through said medium's transition temperature.
Claim 8
Dependent Claim
36 words
The method of claim 2 in which the temperature of said substrate during said high vacuum, molecular beam epitaxy deposition technique can have values in a range from approximately 100 K to less than 270 K.
Claim 9
Dependent Claim
24 words
The method of claim 2 where said high vacuum, molecular beam epitaxial deposition occurs with said substrate at a temperature of about 100 K.
Claim 10
Dependent Claim
24 words
The medium of claim 1 where the orientation of a palladium substrate crystal is such that said palladium substrate has miller indices of (100).
Claim 11
Dependent Claim
28 words
The medium of claim 1 where said medium is thermally stable with respect to the vertical or perpendicular orientation of the magnetization vector for the ultrathin iron film.
Claim 12
Dependent Claim
29 words
The medium of claim 1 in which said medium is magnetically stable with respect to the vertical or perpendicular orientation of the magnetization vector for the ultrathin iron film.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-05-26 | 1995-11-25 | 1996-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-26 | 1999-11-25 | 2000-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-26 | 2003-11-25 | 2004-05-26 | $7700.00 | Window Closed / Lapsed |