MAGNETIC HEAD, AND MAGNETIC STORAGE APPARATUS

• US 20140063648A1
• Filed: 08/06/2013
• Published: 03/06/2014
• Est. Priority Date: 08/29/2012
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: SHIROISHI, Yoshihiro, WATANABE, Katsuro, SATO, Yo
• Granted Patent: US 8,953,282 B2
• Time in Patent Office: Days
• US Class Current: 360/75
• CPC Class Codes: G11B 2005/0024 Microwave assisted recording
• CPC Class Codes: G11B 5/235 Selection of material for gap filler G11B5/232 takes precedence
• CPC Class Codes: G11B 5/3106 where the integrated or assembled structure comprises means for conditioning against physical detrimental influence, e.g. wear, contamination G11B5/3133 takes precedence
• CPC Class Codes: G11B 5/3146 magnetic layers
• CPC Class Codes: G11B 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: G11B 5/3945 Heads comprising more than one sensitive element
• CPC Class Codes: G11B 5/3967 Composite structural arrangements of transducers, e.g. inductive write and magnetoresistive read G11B5/3906 takes precedence
• CPC Class Codes: Y10T 428/1114 having tunnel junction effect
• CPC Class Codes: Y10T 428/1121 Multilayer
• CPC Class Codes: Y10T 428/1171 with defined laminate structural detail

Abstract

In a Spin Torque Oscillator (STO) comprising an underlayer, a first magnetic layer disposed on the underlayer, a non-magnetic intermediate layer disposed on the first magnetic layer, and a second magnetic layer disposed on the non-magnetic intermediate layer, the non-magnetic intermediate layer is a non-magnetic alloy containing 50 at % or more of at least one kind of element selected from a first group consisting of Cu, Ag, and Au, and further at least 0.1 at % or more in total of at least one kind of element selected from a second group consisting of Cu, Ag, Au, Cr, Ti, Zr, Hf, V, Nb, Ta, Ru, Os, Pd, Pt, Rh, and Ir that does not overlap with the element from the first group.

Claims

1. A microwave assisted magnetic recording head comprising:

a recording pole that generates a recording field for recording information in a perpendicular magnetic recording medium; and

a high frequency magnetic field oscillating element disposed adjacent to the recording pole,

wherein;

the high frequency magnetic field oscillating element includes an underlayer, a first magnetic layer disposed on the underlayer, a non-magnetic intermediate layer disposed on the first magnetic layer, and a second magnetic layer disposed on the non-magnetic intermediate layer; and

the non-magnetic intermediate layer is a non-magnetic alloy containing 50 at % or more of at least one kind of element selected from a first group consisting of Cu, Ag, and Au.

2. The microwave assisted magnetic recording head according to claim 1, wherein the non-magnetic intermediate layer contains at least 0.1 at % or more in total of at least one kind of element selected from a second group consisting of Cu, Ag, Au, Cr, Ti, Zr, Hf, V, Nb, Ta, Ru, Os, Pd, Pt, Rh, and Ir that does not overlap with the element from the first group.

3. The microwave assisted magnetic recording head according to claim 1, wherein the non-magnetic intermediate layer contains two or more kinds of the element selected from the first group.

4. The microwave assisted magnetic recording head according to claim 2, wherein at least one of the first magnetic layer and the second magnetic layer is a Heusler alloy.

5. The microwave assisted magnetic recording head according to claim 2, wherein at least one of the first magnetic layer and the second magnetic layer is a magnetic super-lattice thin film of at least two stacked layers of each of a magnetic thin film (a) and a magnetic thin film (b) below:

(a) a CoFe magnetic alloy thin film of Co to which at least 0.1 at % or more and 20 at % or less of Fe is added, or a magnetic alloy thin film containing at least 50% or more of the CoFe magnetic alloy and at least 0.1 at % or more in total and not more than 25 at % independently of at least one kind of element selected from the second group except for Cu; and

(b) an FeCo magnetic alloy thin film of Fe to which at least 0.1 at % or more and 70 at % or less of Co is added, or a magnetic alloy thin film containing at least 50 at % or more of the FeCo magnetic alloy and at least 0.1 at % or more in total and not more than 25 at % independently of at least one kind of element selected from the second group except for Cu.

6. The microwave assisted magnetic recording head according to claim 1, wherein the underlayer contains 50 at % or more of at least one kind of element selected from a second group consisting of Cu, Ag, Au, Cr, Ti, Zr, Hf, V, Nb, Ta, Ru, Os, Pd, Pt, Rh, and Ir, and at least 0.1 at % or more of at least one element that does not overlap therewith.

7. The microwave assisted magnetic recording head according to claim 2, comprising a cap layer contacting the second magnetic layer on the opposite side from the non-magnetic intermediate layer,

wherein the cap layer is a thin film containing 50 at % or more of at least one kind of element selected from the second group and at least 0.1 at % or more of at least one element that does not overlap therewith.

8. The microwave assisted magnetic recording head according to claim 1, wherein:

one of the first magnetic layer and the second magnetic layer is a spin injection layer having a magnetic anisotropy axis in a direction perpendicular to a film plane;

the other is a high frequency magnetic field generation layer having an effective magnetic easy plane in the film plane; and

electric current is caused to flow from the high frequency magnetic field generation layer toward the spin injection layer.

9. A microwave assisted magnetic recording head comprising:

a recording pole that generates a recording field for recording information in a perpendicular magnetic recording medium; and

a high frequency magnetic field oscillating element disposed adjacent to the recording pole,

wherein;

the high frequency magnetic field oscillating element includes an underlayer, a first magnetic layer disposed on the underlayer, a non-magnetic intermediate layer disposed on the first magnetic layer, and a second magnetic layer disposed on the non-magnetic intermediate layer; and

the non-magnetic intermediate layer has a lattice constant mismatch with the adjacent first magnetic layer and second magnetic layer of not more than 4%.

10. The microwave assisted magnetic recording head according to claim 9, wherein the lattice constant mismatch is not more than 1.5%.

11. The microwave assisted magnetic recording head according to claim 9, wherein the underlayer and the first magnetic layer have a lattice constant mismatch of not more than 4%.

12. A microwave assisted magnetic recording/reproducing head comprising:

a recording head for recording information in a perpendicular magnetic recording medium; and

a read head having a magnetic read element disposed between a pair of magnetic shield layers,

wherein;

the magnetic read element includes an underlayer, a first magnetic layer disposed on the underlayer, a non-magnetic intermediate layer disposed on the first magnetic layer, and a second magnetic layer disposed on the non-magnetic intermediate layer; and

the non-magnetic intermediate layer is a non-magnetic alloy containing at least 50 at % or more of at least one kind of element selected from a first group consisting of Cu, Ag, and Au.

13. The microwave assisted magnetic recording/reproducing head according to claim 12, wherein the non-magnetic intermediate layer is a non-magnetic alloy containing at least 0.1 at % or more in total of at least one kind of element selected from a second group consisting of Cu, Ag, Au, Cr, Ti, Zr, Hf, V, Nb, Ta, Ru, Os, Pd, Pt, Rh, and Ir that does not overlap with the element from the first group.

14. The microwave assisted magnetic recording/reproducing head according to claim 12, wherein the non-magnetic intermediate layer contains two or more kinds of the element selected from the first group.

15. The microwave assisted magnetic recording/reproducing head according to claim 12, wherein the non-magnetic intermediate layer has a lattice constant mismatch with the adjacent first magnetic layer and second magnetic layer of not more than 4%.

16. The microwave assisted magnetic recording/reproducing head according to claim 12, wherein at least one of the first magnetic layer and the second magnetic layer is a Heusler alloy or a magnetic super-lattice thin film of at least two stacked layers of each of a magnetic thin film (1) and a magnetic thin film (2) below:

(1) a CoFe alloy thin film of Co to which at least 0.1 at % or more and 20 at % or less of Fe is added, or a magnetic alloy thin film containing at least 50% or more of the CoFe alloy and at least 0.1 at % or more in total and not more than 25 at % independently of at least one kind of element selected from the second group except for Cu; and

(2) an FeCo alloy thin film of Fe to which at least 0.1 at % or more and 70 at % or less of Co is added, or a magnetic alloy thin film containing at least 50 at % or more of the FeCo alloy and at least 0.1 at % or more in total and not more than 25 at % independently of at least one kind of element selected from the second group except for Cu.

17. The microwave assisted magnetic recording/reproducing head according to claim 12, wherein the non-magnetic intermediate layer includes a tunnel barrier layer and a non-magnetic alloy layer.

18. The microwave assisted magnetic recording/reproducing head according to claim 16, wherein the magnetic read element is disposed in a far side in an element height direction of the pair of magnetic shield layers.

19. A magnetic storage apparatus comprising:

a perpendicular magnetic recording medium;

a medium drive unit that drives the perpendicular magnetic recording medium;

a magnetic head that performs recording or reading of information on the perpendicular magnetic recording medium;

a head drive unit that positions the magnetic head with respect to the perpendicular magnetic recording medium; and

a processing unit that controls or processes an operation of the magnetic head,

wherein;

the magnetic head includes a recording pole that generates a recording field, and a high frequency magnetic field oscillating element disposed adjacent to the recording pole;

the high frequency magnetic field oscillating element includes an underlayer, a first magnetic layer disposed on the underlayer, a non-magnetic intermediate layer disposed on the first magnetic layer, and a second magnetic layer disposed on the non-magnetic intermediate layer; and

the non-magnetic intermediate layer is a non-magnetic alloy containing 50 at % or more of at least one kind of element selected from a first group consisting of Cu, Ag, and Au.

20. The magnetic storage apparatus according to claim 19, wherein the non-magnetic intermediate layer contains at least 0.1 at % or more in total of at least one kind of element selected from a second group consisting of Cu, Ag, Au, Cr, Ti, Zr, Hf, V, Nb, Ta, Ru, Os, Pd, Pt, Rh, and Ir that does not overlap with the element from the first group.

21. The magnetic storage apparatus according to claim 19, wherein the underlayer contains 50 at % or more of at least one kind of element selected from a second group consisting of Cu, Ag, Au, Cr, Ti, Zr, Hf, V, Nb, Ta, Ru, Os, Pd, Pt, Rh, and Ir, and at least 0.1 at % or more of at least one kind of element that does not overlap therewith.