Magnetic head made from amorphous magnetic film

• US 4,766,039 A
• Filed: 06/17/1986
• Issued: 08/23/1988
• Est. Priority Date: 06/21/1985
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kumasaka, Noriyuki, Yamashita, Takeo, Shiiki, Kazuo, Hamakawa, Yoshihiro, Otomo, Shigekazu, Saito, Noritoshi
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): Atkinson, William M.
• Application Number:
  US06/875,222
• Time in Patent Office: 798 Days
• Field of Search: 148/309, 148/304, 252/62.55, 360/125, 360/126, 420/424, 420/425, 420/426, 420/427, 420/428, 420/429, 420/430, 420/435, 420/436, 420/439, 420/440, 428/670, 428/672, 428/673, 428/694, 428/900, 428/928, 428/469
• US Class Current: 428/469
• CPC Class Codes: G11B 5/11 Shielding of head against electric or magnetic fields
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• CPC Class Codes: G11B 5/147 with cores being composed of metal sheets, i.e. laminated cores with cores composed of isolated magnetic layers, e.g. sheets in thin films G11B5/31
• CPC Class Codes: G11B 5/31 using thin films G11B5/1274, G11B5/1278, G11B5/1874, G11B5/1875, G11B5/33, G11B5/49 take precedence; magnetic thin film structures H01F10/00
• CPC Class Codes: G11B 5/39 using magneto-resistive devices or effects
• CPC Class Codes: Y10S 428/90 Magnetic feature

Abstract

A magnetic head comprising a magnetic film in at least a part of a magnetic circuit, at least a part of the magnetic film being formed in contact with, or being exposed to, an oxide or oxygen at least in a heating step at 150° C. or higher in a process for preparing the magnetic head is disclosed. An amorphous alloy film for the magnetic film has the following composition formula to give distinguished head characteristics without any oxidation:

Co.sub.a T.sub.b Zr.sub.c N.sub.d

where T is at last one of Nb, Ta, W, Mo, V and Cr; N is at least one of Au, Pt and Ag; d≧1, b>0, b₁ +b₂ +2c≧10, a+d≧80, -1≦(3c-b₁ -3b₂ -5b₃ -3b₄ -4d)/(c+b₁ +b₂ +b₃ +b₄ +d)≦1, and a+b+c+d=100, where b₁ is a Nb concentration, b₂ is a Ta concentration, b₃ is a W concentration, b₄ is sum total of Mo, Cr and V concentrations and b=b₁ +b₂ +b₃ +b₄.

Claims

1. A magnetic head comprising a magnetic circuit, at least a part of said magnetic circuit including a magnetic film, wherein said magnetic film is composed of an amorphous alloy film having the following composition formula:

Co_a T_b Zr_c N_d

wherein T is at least one of Nb, Ta, W, Mo, V, and Cr;

N is at least one of Au, Pt and Ag;

d≧

1, b>

0, b₁ +b₂ +2c≧

10, a+d≧

80, -1≦

(3c-b₁ -3b₂ -5b₃ -3b₄ -4d)/(c+b₁ +b₂ +b₃ +b₄ +d)≦

1, and a+b+c+d=100, where b₁ is a Nb concentration, b₂ is a Ta concentration, b₃ is a W concentration, b₄ is sum total of Mo, Cr and V concentrations, and b=b₁ +b₂ +b₃ +b₄.

2. A magnetic head according to claim 1, wherein said magnetic film is formed in contact with an oxide layer and is subjected to a heating step at an elevated temperature of at least 150°

C.

3. A magnetic head according to claim 1, wherein said magnetic film is in contact with an oxygen-containing layer and is subjected to a heating step at an elevated temperature of at least 150°

C.

4. A magnetic head according to claim 1, wherein said magnetic film is exposed to oxygen while being subjected to a heating step at an elevated temperature of at least 150°

C.

5. A magnetic head according to claim 1, wherein the magnetic film is composed of an amorphous alloy film having the following composition formula:

space="preserve" listing-type="equation">Co.sub.a T.sub.b Zr.sub.c N.sub.d

wherein T is at least one of Nb, Ta, W, Mo, V and Cr;

N is at least one of Au, Pt and Ag;

d≧

3, b>

0, b₁ +b₂ +2c≧

10, a+d≧

80, -1≦

(3c-b₁ -3b₂ -5b₃ -3b₄ -4d)/(c+b₁ +b₂ +b₃ +b₄ +d)≦

1, and a+b+c+d=100, wherein b₁ is a Nb concentration, b₂ is a Ta concentration, b₃ is a W concentration, b₄ is sum total of Mo, Cr and V concentrations and b=b₁ +b₂ +b₃ +b₄.

6. A magnetic head according to claim 5, wherein the magnetic film is composed of an amorphous alloy film having the following composiiton formula:

space="preserve" listing-type="equation">Co.sub.a T.sub.b Zr.sub.c N.sub.d

wherein T is at least one of Nb, Ta, W, Mo, V and Cr;

N is at least one of Au, Pt and Ag;

d≧

3, b>

0, b₁ +b₂ +2c≧

10, a+d≧

80, -0.5≦

(3c-b₁ -3b₂ -5b₃ -3b₄ -4d)/(c+b₁ +b₂ +b₃ +b₄ +d)≦

0.5, and a+b+c+d=100, where b₁ is a Nb concentration, b₂ is a Ta concentration, b₃ is a W concentration, b₄ is sum total of Mo, Cr and V concentrations and b=b₁ +b₂ +b₃ +b₄.

7. A magnetic head comprising a magnetic shield, at least a part of said magnetic shield including a magnetic film, wherein said magnetic film is composed of an amorphous alloy film having the following composition formula:

space="preserve" listing-type="equation">Co.sub.a T.sub.b Zr.sub.c N.sub.d

wherein T is at least one of Nb, Ta, W, Mo, V, and Cr;

N is at least one of Au, Pt and Ag;

d≧

1, b>

0, b₁ +b₂ +2c≧

10, a+d≧

80, -1≦

(3c-b₁ -3b₂ -5b₃ -3b₄ -4d)/(c+b₁ +b₂ +b₃ +b₄ +d)≦

1, and a+b+c+d=100, where b₁ is a Nb concentration, b₂ is a Ta concentration, b₃ is a W concentration, b₄ is sum total of Mo, Cr and V concentrations, and b=b₁ +b₂ +b₃ +b₄.

8. A magnetic head according to claim 7, wherein said magnetic film is formed in contact with an oxide layer and is subjected to a heating step at an elevated temperature of at least 150°

C.

9. A magnetic head according to claim 7, wherein said magnetic film is in contact with an oxygen-containing layer and is subjected to a heating step at an elevated temperature of at least 150°

C.

10. A magnetic head according to claim 7, wherein said magnetic film is exposed to oxygen while being subjected to a heating step at an elevated temperature of at least 150°

C.

11. A magnetic head according to claim 7, wherein said magnetic head is a magnetoresistive head.

12. A magnetic head according to claim 7, wherein the magnetic film is composed of an amorphous alloy film having the following composition formula:

space="preserve" listing-type="equation">Co.sub.a T.sub.b Zr.sub.c N.sub.d

wherein T is at least one of Nb, Ta, W, Mo, V, and Cr;

N is at least one of Au, Pt and Ag;

d≧

3, b>

0, b₁ +b₂ +2c≧

10, a+d≧

80, -1≦

(3c-b₁ -3b₂ -5b₃ -3b₄ -4d)/(c+b₁ +b₂ +b₃ +b₄ +d)≦

1, and a+b+c+d=100, where b₁ is a Nb concentration, b₂ is a Ta concentration, b₃ is a W concentration, b₄ is sum total of Mo, Cr and V concentrations, and b=b₁ +b₂ +b₃ +b₄.

13. A magnetic head according to claim 12, wherein the magnetic film is composed of an amorphous alloy film having the following composition formula:

space="preserve" listing-type="equation">Co.sub.a T.sub.b Zr.sub.c N.sub.d

wherein T is at least one of Nb, Ta, W, Mo, V, and Cr;

N is at least one of Au, Pt and Ag;

d≧

3, b>

0, b₁ +b₂ +2c≧

10, a+d≧

80, -0.5≦

(3c-b₁ -3b₂ -5b₃ -3b₄ -4d)/(c+b₁ +b₂ +b₃ +b₄ +d)≦

0.5, and a+b+c+d=100, where b₁ is a Nb concentration, b₂ is a Ta concentration, b₃ is a W concentration, b₄ is sum total of Mo, Cr and V concentrations, and b=b₁ +b₂ +b₃ +b₄.

14. A magnetic shield for a magnetoresistive head comprising a shield film formed of an amorphous alloy having the following composition formula:

space="preserve" listing-type="equation">Co.sub.a T.sub.b Zr.sub.c N.sub.d

wherein T is at least one of Nb, Ta, W, Mo, V, and Cr;

N is at least one of Au, Pt and Ag;

d≧

1, b>

0, b₁ +b₂ +2c≧

10, a+d≧

80, -1≦

(3c-b₁ -3b₂ -5b₃ -3b₄ -4d)/(c+b₁ +b₂ +b₃ +b₄ +d)≦

1, and a+b+c+d=100, where b₁ is a Nb concentration, b₂ is a Ta concentration, b₃ is a W concentration, b₄ is sum total of Mo, Cr and V concentrations, and b=b₁ +b₂ +b₃ +b₄.

15. A magnetic shield according to claim 14, wherein said shield film is formed in contact with an oxide layer and is subjected to a heating step at an elevated temperature of at least least 150°

C.

16. A magnetic shield according to claim 14, wherein said shield film is in contact with an oxygen-containing layer and is subjected to a heating step at an elevated temperature of at least 150°

C.

17. A magnetic shield according to claim 14, wherein said sheild film is exposed to oxygen while being subjected to a heating step at an elevated temperature of at least 150°

C.

18. A magnetic shield according to claim 14, wherein the shield film is composed of an amorphous alloy film having the following composition formula:

space="preserve" listing-type="equation">Co.sub.a T.sub.b Zr.sub.c N.sub.d

wherein T is at least one of Nb, Ta, W, Mo, V, and Cr;

N is at least one of Au, Pt and Ag;

d≧

3, b>

0, b₁ +b₂ +2c≧

10, a+d≧

80, -1≦

(3c-b₁ -3b₂ -5b₃ -3b₄ -4d)/(c+b₁ +b₂ +b₃ +b₄ +d)≦

1, and a+b+c+d=100, where b₁ is a Nb concentration, b₂ is a Ta concentration, b₃ is a W concentration, b₄ is sum total of Mo, Cr and V concentrations, and b=b₁ +b₂ +b₃ +b₄.

19. A magnetic shield according to claim 18, wherein the shield film is composed of an amorphous alloy film having the following composition formula:

space="preserve" listing-type="equation">Co.sub.a T.sub.b Zr.sub.c N.sub.d

wherein T is at least one of Nb, Ta, W, Mo, V, and Cr;

N is at least one of Au, Pt and Ag;

d≧

3, b>

0, b₁ +b₂ +2c≧

10, a+d≧

80, -0.5≦

(3c-b₁ -3b₂ -5b₃ -3b₄ -4d)/(c+b₁ +b₂ +b₃ +b₄ +d)≦

0.5, and a+b+c+d=100, where b₁ is a Nb concentration, b₂ is a Ta concentration, b₃ is a W concentration, b₄ is sum total of Mo, Cr and V concentrations, and b=b₁ +b₂ +b₃ +b₄.