US4564399A
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Amorphous alloy for magnetic head and magnetic head with an amorphous alloy
Assignee: Toshiba Corp
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Filing: 1984-01-24
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Granted: 1986-01-14
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Expires: 2004-01-24
Abstract
Abstract An amorphous alloy for a magnetic head has a composition which may be represented as Co100-T-X-Y-ZReTHfXBYSiZ, where T, X, Y and Z satisfy the conditions of 0.2</=T</=1.5, 6</=X</=15, 3</=Y</=8 and 0</=Z</=0.01. Such an amorphous alloy has a high crystallization temperature, said temperature being higher than 500 DEG C., and does not lower the effective magnetic permeability, even if gradual cooling is performed after heat treatment. A magnetic head having a core consisting of such an amorphous alloy is not deteriorated in its magnetic properties, even if the head is made by glass bonding.
Inventors
- 👤 Hiroshi Tateishi
- 👤 Susumu Hashimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:29
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/147; H01F1/153; H01F1/15316; C; C22; C22C; C22C45/00; C22C45/04
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
91 words
An amorphous alloy for a magnetic head which, upon gradual cooling from a temperature of 500° C. at a speed of 3° C./minute, exhibits a minimum magnetic permeability above 350 at 5 MHz, and a coercivity maximum of 0.05 Oe, comprising a formula represented as follows: Co.sub.100-T-X-Y-Z Re.sub.T Hf.sub.X B.sub.Y Si.sub.Z, where T, X, Y and Z respectively represent the atomic densities of elements Re, Hf, B and Si, and satisfy the following inequalities of formulae (1) to (5), as follows: 0.2≦T≦6 (1) 6≦X≦15 (2) 3≦Y≦14 (3) 0≦Z≦11 (4) 0.5≦X/(X+Y)≦5/6 (5).
Claim 2
Dependent Claim
91 words
An amorphous alloy for a magnetic head which, upon gradual cooling from a temperature of 500° C. at a speed of 3° C./minute, exhibits a minimum magnetic permeability above 350 at 5 MHz, and a coercivity maximum of 0.05 Oe, comprising a formula represented as follows: Co.sub.100-T-X-Y-Z Re.sub.T Hf.sub.X B.sub.Y Si.sub.Z, where T, X, Y and Z respectively represent the atomic densities of elements Re, Hf, B and Si, and satisfy the following inequalities of formulae (1) to (5), as follows: 0.2≦T≦6 (1) 6≦X≦15 (2) 3≦Y≦14 (3) 0≦Z≦11 (4) 0.5≦X/(X+Y)≦5/6 (5).
Claim 3
Dependent Claim
25 words
The amorphous alloy for a magnetic head according to claim 1, wherein the T factor satisfies the inequality of the following formula (6): 0.2≦T≦1.5 (6).
Claim 4
Dependent Claim
25 words
The amorphous alloy for a magnetic head according to claim 2, wherein the Y factor satisfies the inequality of the following formula (7): 3≦Y≦8 (7).
Claim 5
Dependent Claim
25 words
The amorphous alloy for a magnetic head according to claim 3, wherein the Z factor satisfies the inequality of the following formula (8): 0≦Z≦0.01 (8).
Claim 6
Dependent Claim
98 words
A magnetic head with an amorphous alloy which exhibits a minimum magnetic permeability above 350 at 5 MHz, and a coercivity maximum of 0.05 Oe, after gradual cooling from 500° C. at 3° C./minute, comprising the core, wherein the core is composed of an amorphous alloy having a composition formula represented as follows: Co.sub.100-T-X-Y-Z Re.sub.T Hf.sub.X B.sub.Y Si.sub.Z, where T, X, Y and Z respectively represent the atomic densities of elements Re, Hf, B and Si, and satisfy the following inequalities of formulae (1) to (5), as follows: 0.2≦T≦6 (1) 6≦X≦15 (2) 3≦Y≦14 (3) 0≦Z≦11 (4) 0.5≦X/(X+Y)≦5/6 (5).
Claim 7
Dependent Claim
98 words
A magnetic head with an amorphous alloy which exhibits a minimum magnetic permeability above 350 at 5 MHz, and a coercivity maximum of 0.05 Oe, after gradual cooling from 500° C. at 3° C./minute, comprising the core, wherein the core is composed of an amorphous alloy having a composition formula represented as follows: Co.sub.100-T-X-Y-Z Re.sub.T Hf.sub.X B.sub.Y Si.sub.Z, where T, X, Y and Z respectively represent the atomic densities of elements Re, Hf, B and Si, and satisfy the following inequalities of formulae (1) to (5), as follows: 0.2≦T≦6 (1) 6≦X≦15 (2) 3≦Y≦14 (3) 0≦Z≦11 (4) 0.5≦X/(X+Y)≦5/6 (5).
Claim 8
Dependent Claim
25 words
The magnetic head with an amorphous alloy according to claim 5, wherein the T factor satisfies the inequality of the following formula (6): 0.2≦T≦1.5 (6).
Claim 9
Dependent Claim
25 words
The magnetic head with an amorphous alloy according to claim 6, wherein the Y factor satisfies the inequality of the following formula (7): 3≦Y≦8 (7).
Claim 10
Dependent Claim
25 words
The magnetic head with an amorphous alloy according to claim 7, wherein the Z factor satisfies the inequality of the following formula (8): 0≦Z≦0.01 (8).
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-01-13 | 1989-07-15 | 1990-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-13 | 1993-07-15 | 1994-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-13 | 1997-07-15 | 1998-01-14 | $7700.00 | Window Closed / Lapsed |