US4632883A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vertical recording medium with improved perpendicular magnetic anisotropy due to influence of beta-tantalum underlayer
Assignee: International Business Machines Corp
•
Filing: 1985-04-22
•
Granted: 1986-12-30
•
Expires: 2005-04-22
Abstract
Abstract A thin film alloy disk for vertical magnetic recording has a cobalt-chromium-tantalum (CoCrTa) magnetic layer with perpendicular magnetic anisotropy deposited on an underlayer of beta-tantalum (β-Ta). The β-Ta layer is deposited on a suitable substrate, such as silicon, which is compatible with the formation of the beta phase of tantalum. The highly preferred orientation of the β-Ta film on the substrate and the incorporation of Ta in the magnetic film results in the magnetic film having improved perpendicular magnetic anisotropy, high perpendicular coercivity and low horizontal coercivity. A nickel-iron (NiFe) layer may be deposited between the substrate and the β-Ta underlayer to provide a magnetic flux return path.
Inventors
- 👤 James K. Howard
- 👤 Mohammad T. Moshref
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:08
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/12493; Y10T428/12771; Y10T428/12806; Y10T428/12826; Y10T428/12847; Y10T428/12854; Y10T428/12861; Y10T428/12944; Y10T428/12951
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
91 words
A magnetic recording disk for vertical recording comprising a film of beta-tantalum (β-Ta) on a suitable substrate and a magnetic film of an alloy including cobalt and chromium according to the formula (CoCr) y X 100-y on the β-Ta film, wherein the alloy is of hexagonal crystalline structure with its C-axis oriented generally perpendicular to the substrate, wherein the amount of element X in the alloy is greater than approximately 2 atomic percent, and wherein the element X is selected from the group consisting of Ti, Nb, Mo, Ta, and W.
Claim 2
Dependent Claim
91 words
A magnetic recording disk for vertical recording comprising a film of beta-tantalum (β-Ta) on a suitable substrate and a magnetic film of an alloy including cobalt and chromium according to the formula (CoCr) y X 100-y on the β-Ta film, wherein the alloy is of hexagonal crystalline structure with its C-axis oriented generally perpendicular to the substrate, wherein the amount of element X in the alloy is greater than approximately 2 atomic percent, and wherein the element X is selected from the group consisting of Ti, Nb, Mo, Ta, and W.
Claim 3
Dependent Claim
30 words
The disk according to claim 1 wherein the suitable substrate further comprises a substrate having a film of nickel-iron (NiFe) alloy deposited thereon to provide a magnetic flux return path.
Claim 4
Dependent Claim
12 words
The disk according to claim 1 wherein the suitable substrate is silicon.
Claim 5
Dependent Claim
27 words
The disk according to claim 1 wherein the β-Ta film is a β-Ta film sputter-deposited on the substrate while a bias voltage is applied to the substrate.
Claim 6
Dependent Claim
34 words
The disk according to claim 1 wherein the suitable substrate further comprises a substrate having a nickel-iron (NiFe) compatible adhesion film deposited thereon and a film of nickel-iron (NiFe) deposited on the adhesion film.
Claim 7
Dependent Claim
12 words
The disk according to claim 5 wherein the adhesion film is β-Ta.
References Cited (Backward Citations)
US3515606A
Cited
US3520664A
Cited
US4411963A
Cited
US4079169A
Cited
US4245008A
Cited
JPS5634141A
Cited
US4277809A
Cited
US4410603A
Cited
EP0093838A2
Cited
US4576700A
Cited
JPS5977620A
Cited
US4552820A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-29 | 1990-06-30 | 1990-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-29 | 1994-06-30 | 1994-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-29 | 1998-06-30 | 1998-12-30 | $7700.00 | Window Closed / Lapsed |