JPH0757224A - Magneto-resistance effect type magnetic head and combined magnetic head - Google Patents

Abstract

PURPOSE:To suppress the Barkhausen noise and output fluctuation of the MR head and to make its performance higher and its size smaller. CONSTITUTION:The MR head is formed by disposing an MR magnetosensitive part 46 consisting of an MR element 44 and bias conductor 45 between a first thin-film magnetic core 49 and a second thin-film magnetic core 50, forming the thin-film magnetic core 50 disposed on the bias conductor 45 side of laminated films formed by laminating soft magnetic layers 51, 52 via a nonmagnetic layer 53 held therebetween and specifying the thickness T of this nonmagnetic layer 13 to T<=100nm. A coil 56 for recording of an inductive head is disposed between the MR magnetosensitive part 46 of the MR head and the thin-film magnetic core 50 and a magnetic gap g3 for recording and reproducing between the thin-film magnetic cores 49 and 50 is commonly used as a magnetic gap for reproducing of the MR head and a magnetic gap for recording of the inductive head. The direction of the sense current to be impressed to the MR element 44 at this time may be set in a direction perpendicular to the surface for contact with a magnetic recording medium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive effect type magnetic head suitable for reproduction on, for example, a hard disk and a composite type magnetic head suitable for recording / reproduction.

[0002]

2. Description of the Related Art For example, a recording / reproducing magnetic head of a hard disk drive device is an induction type magnetic head (hereinafter, referred to as
It is called an inductive head. The magnetic head for recording according to (4) and the reproducing head based on a magnetoresistive effect type magnetic head (hereinafter referred to as MR head) having excellent short wavelength sensitivity are generally of a composite type.

As such a composite type magnetic head, for example, one having a structure as shown in FIG. 12 is known. This magnetic head is provided with a reproducing magnetic gap on a substrate 51 called a slider made of, for example, Al ₂ O ₃ —TiC, facing a hard disk contact surface, that is, an ABS (air bearing surface) surface 52. The MR head forming g ₁ and the inductive head forming the recording magnetic gap g ₂ are laminated.

The MR head has a magnetoresistive effect element (hereinafter, referred to as an M element) in which electrodes 53 and 54 are laminated on a front end portion and a rear end portion, respectively.
It is called an R element. ) 55 and a bias conductor 56 that gives the MR element 55 a magnetized state in a predetermined direction.
A pair of thin-film magnetic cores 58, 5 having a magnetic sensitive portion 64, the MR magnetic sensitive portion 64 being made of a soft magnetic material via an insulating layer 57.
It is formed by being sandwiched by nine. That is, the above M
In the R head, as shown in FIG.
By sandwiching the MR element 55 of No. 4 (the electrodes 53 and 54 and the bias conductor 56 are omitted in the figure) between the thin film magnetic cores 58 and 59, recording magnetic fields H ₄ , H ₅ applied from the magnetic recording medium 63, Of the H ₆ , unnecessary recording magnetic fields H ₅ and H ₆ are shielded by the thin film magnetic cores 58 and 59, and only the desired recording magnetic field H ₄ is applied to the MR element 55.

On the other hand, in the inductive head, the upper layer thin-film magnetic core 59 that shields the MR magnetic sensing section 64 is used as one thin-film magnetic core forming a closed magnetic circuit, and is laminated facing the thin-film magnetic core 59. The other thin film magnetic core 60 forms a recording magnetic gap g ₂ facing the ABS surface 52. That is, MR
The thin film magnetic core 60, which is laminated so as to face the upper thin film magnetic core 59 that shields the magnetically sensitive portion 64, has the ABS surface 5 described above.
The recording magnetic gap g ₂ is formed in the facing portion where the front end portion facing 2 is bent toward the thin film magnetic core 59 that functions as a shield and the gap is narrowed.

The thin-film magnetic core 60 is connected to the upper-layer thin-film magnetic core 59 that shields the MR magnetic sensing section 64 on the back side, and the thin-film magnetic core 59 that functions as the shield forms a closed magnetic path. It is like this. Further, a recording coil 61 for applying a magnetic field based on recording information to the thin film magnetic cores 59 and 60.
Is provided in a spiral shape so as to surround the magnetic joint portion 62 which is a connecting portion of the thin film magnetic cores 59 and 60. The recording coil 61 is embedded with an insulating layer 57 in order to electrically insulate it from the thin film magnetic cores 59 and 60.

That is, in the composite magnetic head having the above-mentioned structure, the pair of thin film magnetic cores 58, 5 sandwiching the MR magnetic sensing portion 64 are provided.
MR of the so-called shield type configuration in which 9 is a magnetic shield
A so-called 2-gap in which a head and an inductive head that uses one of the thin film magnetic cores 59 as a core forming a magnetic path and the other thin film magnetic core 60 forms a closed magnetic path are stacked on the same substrate 51. It has a type head configuration. For recording in this composite type magnetic head, an alternating current is supplied to the terminal portion drawn out from the recording coil 61, and a magnetic flux based on the recording information is generated from the recording magnetic gap g ₂ facing the ABS surface 52. On the other hand, for reproduction, a direct current is supplied from the terminal portions drawn out from the front end electrode 53 and the rear end electrode 54 stacked on the front end portion and the rear end portion of the MR element 55, and a sense current is passed to the MR element 55. , A direct current is applied to the terminal portion of the bias conductor 56 to give the MR element 55 a magnetized state in a desired direction to improve the sensitivity.
_{From 1,} the change in the electric resistance of the MR element 55 with respect to the amount of magnetic flux of the recording magnetic field entering the MR element 55 is detected.

[0008]

However, Barkhausen noise and output fluctuation of the MR head are major problems in the composite magnetic head as described above. This is for the following reasons.

For example, in the above MR head, the MR
The thin film magnetic cores 58 and 59 made of a soft magnetic material and arranged so as to sandwich the element 55 and the bias conductor 56,
Shields unnecessary recording magnetic field and bias conductor 5
It also functions as the magnetic path of the bias magnetic field generated from the magnetic field detector 6. However, such thin film magnetic cores 58, 59
In addition, when the recording magnetic field and the bias magnetic field as described above are applied, the magnetization is likely to be discontinuous, and this is detected by the MR element 55 as Barkhausen noise.

That is, for the soft magnetic thin film forming the thin film magnetic cores 58 and 59, for example, the sum of the domain wall energy, anisotropic energy and magnetostatic energy as shown in FIG. 14 is determined to be the minimum. In-plane reflux magnetic domains are generated, and the movement of the domain wall during magnetization is likely to be discontinuous due to impurities in the soft magnetic thin film and surface irregularities, so that the magnetizations of the thin film magnetic cores 58 and 59 are also discontinuous. And Barkhausen noise is detected. The arrow in FIG. 14 indicates the direction of magnetization.

Further, when recording is performed by the inductive head constituting the composite magnetic head, the magnetic domain structure of the soft magnetic thin film constituting the thin film magnetic cores 59 and 60 changes each time the recording magnetic flux flows. As described above, the movement of the domain wall during magnetization is discontinuous, so the energy change accompanying the domain wall movement is irregular.Therefore, there is no reproducibility between the magnetization and the domain structure, and there is variation in the domain structure. Occurs. At this time, the thin film magnetic core 59 is also used as a magnetic core of the inductive head and the MR head. If the magnetic domain structure of the thin film magnetic core 59 varies as described above, the output of the MR head fluctuates.

Therefore, the magnetic domain structure has been stabilized by controlling the magnetic anisotropy and magnetostriction of the soft magnetic thin film that constitutes the thin film magnetic core. With the progress of, it became difficult to stabilize the output sufficiently by this method alone.

Therefore, the present invention has been proposed in view of the conventional circumstances, and suppresses the formation of in-plane return magnetic domains in the soft magnetic thin film forming the thin film magnetic core, suppresses Barkhausen noise, and stabilizes the output. It is an object of the present invention to provide an MR head and a composite type magnetic head.

[0014]

Means for Solving the Problems As a result of intensive studies made by the present inventors in order to achieve the above-mentioned object, as a result of laminating soft magnetic thin films via non-magnetic thin films, the in-plane reflux magnetic domain of the soft magnetic thin films is laminated. It has been found that it is possible to suppress the formation of.

That is, according to the present invention, a magnetoresistive effect magnetic sensing unit comprising a magnetoresistive effect element and a means for applying a bias magnetic field to the magnetoresistive effect element between the first thin film magnetic core and the second thin film magnetic core. In a magnetoresistive effect type magnetic head having a magnetic gap facing the contact surface with the magnetic recording medium, the second thin film magnetic core disposed at least on the bias magnetic field applying side is The soft magnetic layer is a laminated film in which at least two layers are laminated with a nonmagnetic layer interposed therebetween, and the thickness T of the nonmagnetic layer is T ≦ 100 nm.

According to the present invention, in the magnetoresistive effect type magnetic head as described above, the direction of the sense current applied to the magnetoresistive effect element is perpendicular to the contact surface of the magnetic recording medium. It is a feature.

The composite magnetic head of the present invention further comprises a third thin film forming a closed magnetic circuit by the magnetoresistive effect magnetic head as described above and the second thin film magnetic core of the magnetoresistive effect magnetic head. A magnetic core is laminated on the second thin film magnetic core, a recording coil is arranged between them, and a magnetic gap is formed between the front end portions of these thin film magnetic cores so as to face the contact surface with the magnetic recording medium. It is characterized by being laminated with an inductive magnetic head constituting the same.

In the composite magnetic head of the present invention, the recording coil of the inductive magnetic head is arranged between the magnetoresistive effect magnetic sensitive section of the magnetoresistive effect magnetic head and the second thin film magnetic core. , The magnetic gap formed between the first thin film magnetic core and the second thin film magnetic core facing the contact surface with the magnetic recording medium is also used as the magnetic gap of the magnetoresistive effect magnetic head and the induction magnetic head. It is characterized by being done.

[0019]

In the present invention, the thin film magnetic core is a laminated film in which at least two soft magnetic layers are laminated with the nonmagnetic layer sandwiched therebetween, and the thickness T of the nonmagnetic layer is T≤100 nm. Therefore, no in-plane reflux magnetic domain is formed in the thin film magnetic core.

That is, as shown in FIG. 5, the non-magnetic layer 1
The soft magnetic layers 11 and 12 of the thin-film magnetic core 10 in which the soft magnetic layers 11 and 12 are laminated via the magnetic field 3 have opposite directions as indicated by arrows B ₁ and B ₂ in the figure due to magnetostatic interaction. Magnetization occurs, and a reflux magnetic field in the film thickness direction indicated by an arrow H ₁ in the figure is generated between them, and an in-plane reflux magnetic domain is generated to reduce the magnetostatic energy without increasing the domain wall energy and the anisotropic energy. can do. As a result, the soft magnetic layer 1
The in-plane return magnetic domains of 1 and 12 can be eliminated to form a single magnetic domain. Therefore, the thin film magnetic core 10 composed of the soft magnetic films 11 and 12 does not have an in-plane return magnetic domain.

In the composite magnetic head in which the thin film magnetic core 10 is also used as the shield film of the MR head and the magnetic core of the inductive head, the recording magnetic field is recorded on the thin film magnetic core 10 when reproducing as the MR head. Even when a bias magnetic field is applied, since no in-plane return magnetic domain is generated in the thin film magnetic core 10, there is no discontinuous movement of the magnetic domain wall due to magnetization, and Barkhausen noise does not occur. Also, when recording as an inductive head,
Since the soft magnetic thin films 11 and 12 constituting the thin film magnetic core 10 are single magnetic domains, the magnetic domain structure of these does not change due to the recording magnetic flux, and the magnetic domain structure of the thin film magnetic core 10 does not vary. The output of the MR head is also stabilized.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described in detail below with reference to the drawings.

Before describing the magnetic head of the present embodiment, the relationship between the thickness of the nonmagnetic layer and the magnetic domains formed in the plane of the soft magnetic layer when the soft magnetic layers are laminated via the nonmagnetic layer. Describe. That is, a 1.7 μm thick permalloy thin film was used as the soft magnetic layer, and a film thickness of 100 μm was used as the non-magnetic layer.
The magnetic domains formed in the plane of the permalloy thin film were investigated when a Ti thin film of 50 and 10 nm was used and the Ti thin films were sandwiched by the above permalloy thin films to form a two-layer laminated film. The in-plane magnetic domain of the soft magnetic layer of the laminated film having a non-magnetic layer thickness of 100 nm is shown in FIG. 1, and the in-plane magnetic domain of the soft magnetic layer of the laminated film having a non-magnetic layer thickness of 50 nm is shown in FIG. 3 shows the in-plane magnetic domain of the soft magnetic layer of the laminated film in which the thickness of the nonmagnetic layer is 10 nm. Comparing these with the in-plane magnetic domain of the soft magnetic thin film described above, it is remarkably reduced, and the thickness of the nonmagnetic layer is 10 n.
It was confirmed that the laminated film of m had a single magnetic domain. That is, it was confirmed that the formation of the in-plane return magnetic domain was suppressed in the laminated film in which the non-magnetic layer having a film thickness of 100 nm or less was sandwiched by the soft magnetic layers.

Embodiment 1 Next, as an embodiment to which the present invention is applied, at least one thin film magnetic core of a pair of thin film magnetic cores arranged so as to sandwich the MR magnetic sensitive portion has a soft magnetic layer and a nonmagnetic layer. An MR head formed into a laminated film laminated via the above, and a thin film magnetic core further formed on the thin film magnetic core formed of the above laminated film,
An embodiment of a composite magnetic head including an inductive head in which a recording coil is formed between them will be described.

The composite magnetic head of this embodiment is shown in FIG.
ABS surface 1 which is the contact surface with the hard disk
Playback magnetic gap g₁ MR head
The magnetic gap g for recording on the ABS 1 of₂ Inn that faces
The ductive head is Al₂ O ₃ -It consists of TiC substrate
So-called 2 gigs, which are laminated on one side of the slider 2.
It is said to be a cap-type recording / playback head.

The MR head has a pair of electrodes 3a and 3b (hereinafter, referred to as an electrode 3a provided on the ABS surface 1 side) for passing a sense current from a constant current source (not shown) to the front end portion and the rear end portion, respectively. , The electrode 3b provided on the rear end electrode side is referred to as a rear end electrode 3b), and a magnetoresistive effect sense composed of an MR element 4 and a bias conductor 5 for applying a magnetic field state in a predetermined direction to the MR element 4. Magnetic part 6 (hereinafter M
It is referred to as an R magnetic field sensing unit 6. ) Is sandwiched between thin film magnetic cores 9 and 10 made of a soft magnetic material.

The MR element 4 is formed as a rectangular pattern slightly narrower than the track width of the recording magnetic gap g ₂ of the inductive head, and is provided such that its longitudinal direction is orthogonal to the ABS surface 1. At the same time, one end of the ABS faces the ABS surface 1. The MR element 4 has a structure in which a pair of MR thin films that are magnetostatically coupled via a non-magnetic insulating layer are laminated to avoid generation of Barkhausen noise. The MR thin film is a ferromagnetic thin film,
The film thickness is about several hundred angstroms.

On the other hand, the bias conductor is formed as an elongated wiring pattern having a rectangular shape in a plan view, and the MR element 4 is formed.
The insulating layer 8 is laminated on the upper side with a predetermined distance. Further, the bias conductor 5 is provided in a direction substantially orthogonal to the MR element 4, that is, in a form crossing the MR element 4. A bias current, which is a direct current, is supplied to the bias conductor 5 in the longitudinal direction, and a bias magnetic field is applied to the MR element 4 in a direction orthogonal to the ABS surface 1.

As described above, in the MR head, the MR magnetic sensitive portion 6 composed of the MR element 4 and the bias conductor 5 is made of the first thin film magnetic material made of a soft magnetic material such as permalloy via the insulating layer 8. It is sandwiched between the core 9 and the second thin film magnetic core 10 to form a so-called shield type structure.
The soft magnetic material may be permalloy or the like, and may be a crystalline material or an amorphous material.

The thin film magnetic core 9 provided on the lower side of the MR element 4 is made so that one end thereof faces the ABS surface via the insulating layer 8 with the slider 1.
It is provided so as to extend in a direction substantially orthogonal to the surface 1.

On the other hand, the other thin film magnetic core 10 provided so as to face the thin film magnetic core 10 is the same as the thin film magnetic core 9 described above.
It is provided so as to extend in a direction substantially orthogonal to the ABS surface 1 with one end thereof facing the BS surface 1. In particular, in this embodiment, the thin-film magnetic core 10 has a pair of soft magnetic layers 1 with the non-magnetic layer 13 sandwiched therebetween.
1 and 12 are laminated. The soft magnetic layer has a thickness of 3.5 μm, and the nonmagnetic layer 13 has a thickness of 10 nm. The materials forming the soft magnetic layers 11 and 12 are as described above.
The materials forming 1, 2 may be the same or different, and as the non-magnetic material forming the non-magnetic layer 13,
Ti or the like can be used, and both conductive and non-conductive materials can be used.

On the other hand, in the inductive head,
The thin film magnetic core 10 which is the above laminated film is used as the other thin film magnetic core forming a closed magnetic path, and the ABS surface 1 is faced by the third thin film magnetic core 14 which is laminated facing the thin film magnetic core 10. Thus, a recording magnetic gap g ₂ is formed between the front ends thereof. The third thin film magnetic core 14 magnetically contacts the thin film magnetic core 10 at its rear end to form a back gap.

Then, in the magnetic coupling portion 15 which is a connecting portion between the third thin film magnetic core 14 and the thin film magnetic core 10,
A spiral recording coil 16 is provided so as to surround the magnetic coupling portion 15. The recording coil 16 is embedded with an insulating layer 8 in order to ensure insulation between the third thin film magnetic core 14 and the thin film magnetic core 10. The insulating layer 8 also functions as a protective film for protecting the MR head and the inductive head laminated on the slider 2 also on the third thin film magnetic core 14.
Is provided.

As described above, in the composite magnetic head of this embodiment, the thin film magnetic core 10 which is also used as the magnetic core of the MR head and the inductive head has the soft magnetic layers 11 and 12 and the non-magnetic layer 13 interposed therebetween. It is a laminated film. Therefore, no in-plane return magnetic domain is generated in the thin film magnetic core 10.

That is, as shown in FIG. 5, the soft magnetic layers 11 and 12 constituting the thin film magnetic core 10 have opposite directions as indicated by arrows B ₁ and B ₂ in the figure due to magnetostatic interaction. Magnetization occurs, and a reflux magnetic field in the film thickness direction indicated by an arrow H ₁ in the figure is generated between them, and an in-plane reflux magnetic domain is generated to reduce the magnetostatic energy without increasing the domain wall energy and the anisotropic energy. can do. As a result, the in-plane return magnetic domain of the soft magnetic layers 11 and 12 can be eliminated and a single magnetic domain can be formed. Therefore, the thin film magnetic core 10 composed of the soft magnetic films 11 and 12 does not have an in-plane return magnetic domain.

When reproducing with the MR head, even if a recording magnetic field and a bias magnetic field are applied to the thin film magnetic core 10, no in-plane return magnetic domain is generated in the thin film magnetic core 10, so that there is a discontinuity associated with the magnetization. Barkhausen noise does not occur because the domain wall does not move.

Further, when recording is performed by the inductive head, the soft magnetic thin film 1 constituting the thin film magnetic core 10 is formed.
Since 1 and 12 are single magnetic domains, the magnetic domain structure does not change due to the recording magnetic flux.
There is no variation in the magnetic domain structure of 0, and the output of the MR head is stabilized. For these reasons, the magnetic head can be made smaller and have higher performance.

Therefore, in order to confirm the effect of the magnetic head of this embodiment, the output of the MR head of the magnetic head of this embodiment and the output of the MR head of the conventional magnetic head were compared.
That is, the soft magnetic layers 11 and 12 constituting the thin film magnetic core 10 of the magnetic head of the present embodiment are made of a 3.5 μm thick permalloy thin film, and the nonmagnetic layer 13 is made of a Ti thin film having a thickness of 10 nm. The output of the MR head is measured, and the thin-film magnetic core 59 of the conventional magnetic head shown in FIG. 12 is a permalloy thin film having the same thickness as that of the thin-film magnetic core 10 of the above-mentioned embodiment.
The output of the head was measured. The results are shown in Table 1.

[0039]

[Table 1]

As can be seen from the results in Table 1, the magnetic head of the present embodiment suppresses the output fluctuation, while the conventional magnetic head has a large output fluctuation.
From this result, as described above, in the magnetic head of the present embodiment, the output fluctuation is suppressed because the occurrence of the in-plane return magnetic domain is suppressed, and in the conventional magnetic head, the in-plane of the thin film magnetic core 59 is suppressed. It was confirmed that the output fluctuation was large due to the occurrence of the reflux magnetic domain.

Up to now, in the magnetic head of this embodiment, the sense current applied to the MR element has a so-called vertical type M in which the direction of the sense current is perpendicular to the contact surface of the magnetic recording medium.
Although the composite magnetic head using the R head has been described, the present invention provides a so-called horizontal MR head in which the direction of the sense current applied to the MR element is horizontal to the contact surface of the magnetic recording medium. It is also applicable to the used composite type magnetic head.

In the magnetic head of this embodiment,
The bias magnetic field is used as the means for applying the bias magnetic field to the MR element.
For example, as shown in FIG. 6, an electromagnet 25 is arranged instead of the bias conductor, and a DC current is applied to the electromagnet 25 to apply a bias magnetic field h.
₃ may be generated, or the bias magnetic field h ₄ may be generated by disposing the permanent magnet 26 instead of the bias conductor as shown in FIG. 7. Further, as described above, when the horizontal MR head is used, the bias conductor 30 is arranged so as to be in contact with the MR element 29 arranged between the thin film magnetic cores 27 and 28, and the direct current is applied to the bias conductor 30. A bias magnetic field h ₅ may be generated by applying a current. As shown in FIG. 9, a magnetic film 34 is arranged in the vicinity of the MR element 33 arranged between the thin film magnetic cores 31 and 32, and the magnetic film 34 is The MR element 33 may be magnetized by the sense current to generate the bias magnetic field h ₆ .

Further, in the magnetic head of this embodiment, the thin film magnetic core which is also used as the thin film magnetic core of the MR head and the inductive head is a laminated film in which two soft magnetic layers are stacked with the nonmagnetic layer interposed therebetween. Figure 1 shows a thin film magnetic core
As shown in the figure, between the soft magnetic layers 35a and 35b, 35b and 35c, even if a multilayer laminated film of two or more layers as shown in FIG.
A return magnetic field in the film thickness direction is generated between the adjacent soft magnetic layers 35 such as a space, and no in-plane return magnetic domain is generated in each soft magnetic layer 35. Therefore, the magnetic head using the same also has the magnetic head of this embodiment. The same effect as is expected.

Embodiment 2 In this embodiment, at least one thin film magnetic core of a pair of thin film magnetic cores arranged so as to sandwich the MR magnetic sensitive portion has a soft magnetic layer laminated via a nonmagnetic layer. The recording coil of the inductive head is arranged between the MR magnetic sensing part of the MR head and the thin film magnetic core composed of the above-mentioned laminated film, and the recording coil of the inductive head is provided between the pair of thin film magnetic cores on the contact surface with the magnetic recording medium. An embodiment of a composite type magnetic head in which the magnetic gap formed so as to face is also used as the magnetic gap of the MR head and the inductive head will be described.

As shown in FIG. 11, the magnetic head of this embodiment has a thin film magnetic core made of a soft magnetic material so that the ABS surface 41, which is the contact surface with the hard disk, faces the recording / reproducing magnetic gap g _3. 49 and 50 are arranged, and the MR magnetic sensing section 46 and the recording coil 56 are arranged between them, and these are laminated on one side surface of the slider 42 to form a so-called single-pole recording / reproducing head. Has been done.

At this time, especially in the magnetic head of this embodiment, the thin film magnetic core 5 arranged on the recording coil 56 side.
No. 0 has a structure in which a pair of soft magnetic layers 51 and 52 are laminated so as to sandwich the non-magnetic layer 53 therebetween. The thickness of the nonmagnetic layer 53 is 100 μm or less,
Examples of the material constituting this include Ti and the like, which may be conductive or non-conductive materials.
Examples of the material forming the magnetic layer include permalloy and the like, and any of crystalline and amorphous materials may be used.
The materials forming 1, 52 may be the same or different materials. The thin film magnetic core 50 contacts the thin film magnetic core 49 at the rear end thereof at the magnetic coupling portion 55 to form a back gap.

Further, also in the magnetic head of this embodiment,
Similar to the magnetic head of the first embodiment, the MR magnetic sensing unit 46 has a front electrode 43a and a rear electrode 43b for passing a sense current.
Of the MR element 44 and a bias conductor 45 which gives the MR element 44 a magnetic field in a desired direction. The MR element 44 and the bias conductor 45 have the same shape, configuration and function as the MR element 4 and the bias conductor 5 of the magnetic head of the first embodiment.

The recording coil 56 is provided in a spiral shape so as to surround the magnetic coupling portion 55 of the thin film magnetic cores 49 and 50. The MR element 4
It goes without saying that the insulating layer 48 is interposed between the 4, the bias conductor 45, the recording coil 56, and the thin film magnetic cores 49 and 50.

Therefore, in the magnetic head of this embodiment, the thin film magnetic cores 49 and 50 function as a shield of the MR magnetic sensing part 46 to form the MR magnetic sensing part 46 and the MR head, and also as a magnetic core. It functions and constitutes the recording coil 56 and the inductive head.

Also in the magnetic head of this embodiment, the thin film magnetic cores 49, 50 and the MR magnetic sensing section 46,
The recording coil 56 is provided on the slider 4 via the insulating layer 48.
2, and an insulating layer 48 is also formed on the thin film magnetic core 50 to protect them.

In the magnetic head of this embodiment, the thin film magnetic core 50 is provided with the non-magnetic layer 53 and the soft magnetic layers 51 and 52.
Since the in-plane return magnetic domain is not generated in the thin film magnetic core 50, even if the magnetic head is made to function as an inductive head and a current is supplied to the recording coil 56 to generate a recording magnetic field, There is no variation in the magnetic domain structure of the thin film magnetic core. Therefore, even if the thin film magnetic cores 49 and 50 are used as the magnetic core of the inductive head and the shield of the MR head as described above,
It does not affect the output of the MR head. From this, the miniaturization of the magnetic head is also achieved.

In the magnetic head of this embodiment,
As with the magnetic head of the first embodiment, generation of Barkhausen noise can be suppressed. Further, in the magnetic head of the present embodiment, the soft magnetic layers 52, 5 which compose the thin film magnetic core 50.
Since the thickness of 3 is thinner than that of the conventional magnetic head, the current loss when a high frequency recording magnetic field is applied to the thin film magnetic core 50 is reduced, and the magnetic permeability of the thin film magnetic core 50 is improved.
The recording current can be reduced, and the power consumption of the head can be reduced. Further, from the above, the miniaturization and high performance of the magnetic head can be achieved.

[0053]

As is apparent from the above description, in the present invention, a magnetoresistive effect element and a bias magnetic field are applied to the magnetoresistive effect element between the first thin film magnetic core and the second thin film magnetic core. Of the magnetoresistive effect magnetic field sensing section, and a magnetic resistance effect type magnetic head having a magnetic gap facing the contact surface with the magnetic recording medium is disposed at least on the bias magnetic field applying side. The second thin film magnetic core is a laminated film in which at least two soft magnetic layers are laminated with a nonmagnetic layer sandwiched therebetween, and the thickness T of the nonmagnetic layer is T ≦ 100 nm. An in-plane reflux magnetic field is not generated in the second thin film magnetic core, and even if a recording magnetic field or a bias magnetic field is applied to the second thin film magnetic core, there is no discontinuous movement of the domain wall due to magnetization, Generation of Barkhausen noise It is suppressed. As a result, it is possible to improve the performance and downsize the magnetoresistive head.

In the composite magnetic head of the present invention, the magnetoresistive effect type magnetic head as described above and the second thin film magnetic core of the magnetoresistive effect type magnetic head constitute a third magnetic path. A thin film magnetic core is laminated on the second thin film magnetic core, a recording coil is arranged between them, and a magnetic gap is formed between the front end portions of these thin film magnetic cores so as to face the contact surface with the magnetic recording medium. Since the in-plane magnetic flux return domain is not generated in the second thin film magnetic core, the magnetic domain structure of the second thin film magnetic core does not vary during recording, and The output of the resistance effect type magnetic head is stabilized. As a result, it is possible to improve the performance and downsize the composite magnetic head.

Further, in the composite type magnetic head of the present invention, the recording coil of the induction type magnetic head is arranged between the magnetoresistive effect magnetic sensitive section of the magnetoresistive effect type magnetic head as described above and the second thin film magnetic core. The magnetic gap formed between the first thin film magnetic core and the second thin film magnetic core facing the contact surface with the magnetic recording medium serves as the magnetic gap between the magnetoresistive effect magnetic head and the inductive magnetic head. Since they are also used, high performance and miniaturization are achieved. Further, since the magnetic permeability of the second thin film magnetic core is increased, the recording current can be reduced and the electric power of the composite magnetic head can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view showing an in-plane magnetic domain of a soft magnetic layer of a laminated film having a nonmagnetic layer thickness of 100 nm.

FIG. 2 is a schematic diagram showing in-plane magnetic domains of a soft magnetic layer of a laminated film having a nonmagnetic layer thickness of 50 nm.

FIG. 3 is a schematic diagram showing in-plane magnetic domains of a soft magnetic layer of a laminated film having a nonmagnetic layer thickness of 10 nm.

FIG. 4 is a schematic cross-sectional view of essential parts showing a magnetic head of Example 1.

FIG. 5 is a schematic diagram showing the states of magnetization and magnetic field in the thin film magnetic core of the magnetic head of Example 1.

FIG. 6 is a schematic cross-sectional view of a main part schematically showing an example of means for applying a bias magnetic field.

FIG. 7 is a schematic cross-sectional view of a main part schematically showing another example of a means for applying a bias magnetic field.

FIG. 8 is a schematic cross-sectional view of a main part, which schematically shows still another example of a means for applying a bias magnetic field.

FIG. 9 is a schematic cross-sectional view of a main part schematically showing still another example of the means for applying a bias magnetic field.

FIG. 10 is a schematic diagram showing a state of a magnetic field in a thin film magnetic core when the thin film magnetic core is a multilayer laminated film.

FIG. 11 is a schematic cross-sectional view of essential parts showing a magnetic head of Example 2.

FIG. 12 is a schematic cross-sectional view of an essential part showing a conventional composite magnetic head.

FIG. 13 is a schematic view showing the vicinity of an MR magnetic sensing part of a conventional composite magnetic head.

FIG. 14 is a schematic diagram showing an in-plane reflux magnetic field of a soft magnetic thin film forming a thin film magnetic core of a conventional composite magnetic head.

[Explanation of symbols]

1, 41 ... ABS surface 3a, 43a ... Front electrode 3b, 43b ... Rear electrode 4,44 ... MR element 5, 45 ... Bias conductor 6, 46 ... MR magnetic sensitivity Part 9, 10, 14, 49, 50 ... Thin film magnetic core 11, 12, 51, 52 ... Soft magnetic layer 13, 53 ... Non-magnetic layer 16, 56 ... Recording coil g _1. ... reproducing magnetic gap g ₂ ··· recording magnetic gap g ₃ ··· recording and reproducing magnetic gap

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Terui 6-735 Kitashinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (4)

[Claims] 1. A magnetoresistive effect magnetic sensing section comprising a magnetoresistive effect element and a means for applying a bias magnetic field to the magnetoresistive effect element is arranged between the first thin film magnetic core and the second thin film magnetic core, In a magnetoresistive effect magnetic head having a magnetic gap facing a surface facing a magnetic recording medium, at least a second thin-film magnetic core arranged on a bias magnetic field applying side has a soft magnetic layer. A magnetoresistive effect magnetic head, which is a laminated film in which at least two layers are laminated with a nonmagnetic layer interposed therebetween, and the thickness T of the nonmagnetic layer is T ≦ 100 nm. 2. The magnetoresistive effect type magnetic head according to claim 1, wherein the direction of the sense current applied to the magnetoresistive effect element is a direction perpendicular to the contact surface of the magnetic recording medium. 3. A third thin-film magnetic core forming a closed magnetic path by the magnetoresistive magnetic head according to claim 1 and a second thin-film magnetic core of the magnetoresistive magnetic head. An induction type magnetic head that is laminated on a thin film magnetic core, and a recording coil is arranged between them, and forms a magnetic gap between the front end portions of these thin film magnetic cores facing the contact surface with the magnetic recording medium; A composite type magnetic head comprising: 4. The first thin film magnetic core, wherein the recording coil of the inductive magnetic head is arranged between the magnetoresistive effect magnetic sensing part of the magnetoresistive effect magnetic head according to claim 1 and the second thin film magnetic core. The magnetic gap formed between the first thin film magnetic core and the second thin film magnetic core facing the contact surface with the magnetic recording medium is also used as the magnetic gap of the magnetoresistive effect type magnetic head and the induction type magnetic head. Composite magnetic head.