JPH0668427A - Magneto-resistance effect type head and its manufacture - Google Patents

Abstract

PURPOSE:To provide a magneto-resistance effect type head in which a Barkhausen noise can be suppressed and with high output by stack-ink magnetic domain control film and magneto-resistance effect film between electrodes, and attaching magnetic anisotropy on them in directions different from each other. CONSTITUTION:The magnetic domain control film 12 and the magneto-resistance effect film 11 are stacked on lover gap film 19 formed on lower shield film 17 on a nonmagnetic substrate 10 so as to keep magnetic continuity. After that, the magnetic anisotropy in the directions different from each other are attached on the film 12 and the film 11. Thereby, an effective anisotropic magnetic field when the film 12 and the film 11 are stacked can be decreased, which improves sensitivity. Therefore, it is possible to suppress the Barkhausen noise and to improve the sensitivity and to obtain high output in the magneto- resistance effect type head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive head used for reproducing magnetically recorded information and a magnetic disk device using the same, and more particularly to a magnetoresistive effect with high sensitivity and high output. The present invention relates to a die head and a magnetic disk device using the same.

[0002]

2. Description of the Related Art It has been known that magnetically recorded information can be reproduced by using a magnetoresistive (hereinafter referred to as MR) element. With the progress of densification, development of an MR head that can obtain a high reproduction output voltage without depending on the relative speed of the disk and the head is urgently required. In the MR element, since the electric resistance changes depending on the angle formed by the magnetization vector and the current, the rotation of the magnetization is preferable as the mechanism of the change of the magnetization due to the magnetic field from the medium, not the domain wall movement. Further, when the domain wall motion occurs, it appears as Barkhausen noise in the reproduced waveform and causes a read error, so the domain wall motion must be suppressed.

For this reason, means have been invented for controlling the magnetic domain structure such that the MR film has a single magnetic domain structure composed of a single magnetic domain, or domain wall movement is suppressed. Specifically, a method of stacking an antiferromagnetic film and an MR film in JP-A-62-40610 to form a single domain structure by magnetic exchange coupling is disclosed in JP-A-2-220213. There has been proposed a method of stacking layers to form a single domain structure.

[0004]

However, while the methods described in JP-A-62-40610 and JP-A-2-220213 can surely control the magnetic domain structure of the MR film, The effective anisotropic magnetic field becomes large and the magnetization rotation hardly occurs. Therefore, if an antiferromagnetic film or a permanent magnet film is laminated on the MR film at the portion where the magnetoresistive film detects the magnetic field from the medium, there is a problem that the output of the magnetic head is reduced. Further, in order to suppress an increase in the effective anisotropic magnetic field in the portion where the magnetoresistive film detects the magnetic field of the medium, that is, between the electrodes, a structure excluding the antiferromagnetic film or the permanent magnet film is used. Then, although the sensitivity is improved, there is a problem that a magnetic domain wall appears in the MR film at the end of a film that controls the magnetic domain structure (hereinafter referred to as a magnetic domain control film), and Barkhausen noise may occur.

As described above, the control of the magnetic domain structure of the MR film and the effective anisotropic magnetic field have a close relationship, but in the above-mentioned prior art, the anti-strength which greatly affects the effective anisotropic magnetic field. No mention is made of the direction of magnetic anisotropy of the magnetic film or the direction of magnetization of the permanent magnet film and the direction of magnetic anisotropy of the MR film.

An object of the present invention is to provide a magnetoresistive head having a means for suppressing or reducing Barkhausen noise, which is capable of suppressing Barkhausen noise and having high sensitivity and high output. To do.

[0007]

In order to achieve the above object, the present invention provides a substrate, a magnetoresistive film having uniaxial magnetic anisotropy, and a uniaxial magnetic anisotropy on the substrate. Then, in a magnetoresistive head having a magnetic domain control film for controlling magnetic domains of the magnetoresistive film, and a pair of electrodes for flowing a current through the magnetoresistive film, a magnetoresistive film,
In order to reduce or suppress Barkhausen noise, the magnetic domain control film for controlling the magnetic domain structure of the magnetoresistive film is laminated so that magnetic continuity is maintained by the interface between the two films. The easy axis of magnetic anisotropy and the easy axis of uniaxial magnetic anisotropy of the magnetic domain control film are provided in different directions.

Further, a magnetic thin film is disposed between the magnetoresistive film and the magnetic domain control film, and a laminated structure in which magnetic continuity is maintained at each interface is provided, whereby the magnetic domain control strength is improved. Can be adjusted to any strength.

Here, as the magnetoresistive effect film, for example, an Fe-Ni-based alloy, a Co-Ni-based alloy or an Fe-Ni-Co-based alloy having a large magnetoresistance change rate is used, and as the magnetic domain control film, antiferromagnetic material Membranes or permanent magnet membranes can be used. Further, as the magnetic thin film, for example, an Fe-Ni-Nb based alloy can be used.

With the above-described head structure, the following method can be used as a method of imparting uniaxial magnetic anisotropy to the magnetoresistive effect film and the magnetic domain control film. When the magnetic domain control film is composed of an antiferromagnetic film, first, the magnetoresistive film is formed while applying a magnetic field, then the magnetic domain control film is laminated, and then the magnetic domain control film is strengthened. Magnetic material
It is possible to use a method of applying a DC magnetic field larger than the anisotropic magnetic field of the magnetoresistive effect film in a direction different from the magnetic anisotropy of the magnetoresistive effect film while heating to a temperature not lower than the cooling temperature. When the magnetic domain control film is a permanent magnet film, first, the magnetoresistive effect film is formed while applying a magnetic field, then the magnetic domain control film is formed, and then the magnetic anisotropic film of the magnetoresistive effect film is formed. It is possible to use a method in which a DC magnetic field is applied in a direction different from the magnetic property to magnetize.

[0011]

The effect of controlling the magnetic domain structure of the magnetoresistive (hereinafter referred to as MR) film, that is, the effect of reducing or suppressing Barkhausen noise is wide in the region where the MR film and the magnetic domain control film are magnetically continuous. , The larger the exchange coupling magnetic field between the MR film and the magnetic domain control film, the larger the magnetic field. Regarding the MR film,
The MR film is provided with magnetic anisotropy because, for example, the anisotropic thin film has a larger magnetoresistance change than the magnetically isotropic thin film with respect to the magnetic field from the medium.

Conventionally, in order to sufficiently control the magnetic domain structure, the direction of the magnetic anisotropy of the MR film and the direction of the magnetic anisotropy of the magnetic domain control film are the same as shown in FIG. The space direction (hereinafter referred to as the track width direction) was used. The anisotropy field in the track width direction (hereinafter referred to as the effective anisotropy field) has a large effect on the sensitivity, and the smaller the effective anisotropy field, the higher the sensitivity. In this case, when the magnitude of the exchange coupling magnetic field between the MR film and the magnetic domain control film is He and the magnitude of the anisotropic magnetic field of the MR film is Hk, the MR
The magnitude Hk 'of the effective anisotropic magnetic field when the film and the magnetic domain control film are laminated is the sum (He + Hk) of both.

As in the magnetoresistive head of the present invention, the magnetic field of the MR film is changed as shown in FIG. 1A without changing the magnitude of the exchange coupling magnetic field and the anisotropic magnetic field of the MR film. When the easy axis of anisotropy and the easy axis of magnetic anisotropy of the magnetic domain control film are given in different directions, Hk ′ is obtained when the directions of magnetic anisotropy of the MR film and the magnetic domain control film are the same. Value (He
It becomes smaller than + Hk). That is, Hk '<He + Hk. Further, when the direction of magnetic anisotropy of the MR film and the direction of magnetic anisotropy of the magnetic domain control film are orthogonal to each other as shown in FIG. 1B, Hk 'can be reduced to (-He + Hk). . FIG. 2 illustrates what has been described above.
With the magnetic domain structure of the R film being controlled, Hk 'changes from Hk' = He + Hk when the magnetic anisotropy directions of the conventional MR film and the magnetic domain control film are the same, to Hg 'in different directions. Hk '=-
It can be reduced to He + Hk, which appears as an increase in output as shown in FIG.

Although Hk 'can be reduced by such a method, depending on the materials of the MR film and the magnetic domain control film and the strength of the exchange coupling, it may not be suitable for practical use unless further reduced. In such a case, it is difficult to change the anisotropic magnetic field of the MR film because it is almost determined by the material. Therefore, as shown in FIG. 4, Hk 'can be reduced by inserting a magnetic thin film between the MR film and the magnetic domain control film to reduce the strength of exchange coupling to an arbitrary strength. As the magnetic thin film, a material having a saturation magnetization smaller than that of the MR film and a temperature at which the magnetization disappears is higher than a temperature at which the exchange coupling between the MR film and the magnetic domain control film disappears.
The smaller the saturation magnetization of the magnetic thin film, the smaller the strength of exchange coupling. Therefore, it is possible to select the material of the magnetic thin film by previously obtaining the desired strength of the exchange coupling and calculating the saturation magnetization of the magnetic thin film that can realize this exchange coupling.

As described above, the magnetic anisotropy is imparted to the MR film and the magnetic domain control film in directions different from each other, thereby reducing the magnetic anisotropy and improving the sensitivity. Also, since the magnetic film is magnetically continuous at the interface between the MR film and the magnetic domain control film, the magnetic domain control effect does not deteriorate, and the MR film can be kept in a single magnetic domain. Therefore, microscopically, MR
The spin direction of the film is parallel to the spin of the magnetic domain control film at the interface with the magnetic domain control film due to exchange coupling, but as it moves away from the interface, it is oriented in an anisotropic direction.
Macroscopically, the easy axis of magnetization of the MR film is oriented in a direction different from that of the magnetic domain control film.

Although the magnetic anisotropy is imparted to the MR film and the magnetic domain control film in directions different from each other, the magnetic anisotropy of the MR film produced in a magnetic field is mainly due to the atomic pair. It is utilized that the directional arrangement causes almost no change at a temperature of about the Neel temperature of the antiferromagnetic film or a magnetic field of about the magnetizing magnetic field of the permanent magnet film.

In the magnetoresistive head using the present invention, the MR film and the magnetic domain control film have magnetic continuity with the magnetoresistive film at the interface thereof, and
Whether or not the magnetoresistive film has an easy axis of magnetization different from the easy axis of the magnetic domain control film is confirmed by examining whether or not it has the following properties. can do. First, when an antiferromagnetic film is used as the magnetic domain control film, if the magnetoresistive head is heated above the nail temperature, the directions of magnetic anisotropy of the MR film and the magnetic domain control film will be aligned. The magnetization of the MR film becomes hard to rotate, and the output of the head decreases. In the case where a means for applying a magnetic bias is provided, the optimum bias value at which the reproduced waveform becomes positive and negative symmetrical changes before and after the temperature is raised to the nail temperature or higher. When a permanent magnet film is used as the magnetic domain control film, the output changes when a strong external magnetic field is applied to change the direction of magnetization. In general, either the MR film or the magnetic domain control film has an easy axis of magnetization in the direction of the gap between the pair of electrodes, that is, the track width direction, so no magnetic pole appears in the cross section of the film, but in the track width direction. A magnetic pole appears in a film having no easy axis of magnetization. On the air bearing surface of the head,
It can also be detected by a magnetic force microscope. By confirming these properties, it can be determined whether or not the head has the configuration of the present invention.

[0018]

EXAMPLE One example of a magnetic disk device to which the magnetoresistive head of the present invention is applied will be described with reference to FIG. FIG. 8 is a perspective view showing a schematic structure of this magnetic disk device.

A schematic structure of this magnetic disk device will be described. As shown in the figure, the magnetic disk device includes a spindle 202 and a plurality of magnetic disks 204a, 204b, 20 stacked at equal intervals around the spindle 202 as an axis.
4c, 204d, 204e, and a motor 203 for driving the spindle 202. Further, the movable carriage 206 and the magnetic head groups 205a, 205b, 205c, 205d held by the carriage 206.
And a magnet 208 and a voice coil 207 that constitute a voice coil motor 213 that drives the carriage 206, and a base 201 that supports the magnet. In addition, a higher-level device 2 such as a magnetic disk controller
A voice coil motor control circuit 209 for controlling the voice coil motor 213 in accordance with the signal sent from 12 is provided. Further, a function of converting the data sent from the higher-level device 212 into a current that should be passed through the magnetic head in accordance with the writing method of the magnetic disk 204a and the like, and amplifying the data sent from the magnetic disk 204a and the like,
A write / read circuit 210 having a function of converting into a digital signal is provided, and the write / read circuit 210 is
It is connected to the host device 212 via the interface 211.

Next, the operation of the magnetic disk device for reading data from the magnetic disk 204d will be described. The interface 211 from the host device 212
The voice coil motor control circuit 209 is instructed via the command of the data to be read. The voice coil motor 213 drives the carriage 206 by the control current from the voice coil motor control circuit 209, and the magnetic head groups 205a, 205b, 20 are moved to the positions of the tracks on the magnetic disk 204d where the instructed data are stored.
5c and 205d are moved at high speed to accurately position them. This positioning is performed by the voice coil motor control circuit 20.
The positioning magnetic head 205b connected to
This is performed by detecting and providing the position on the magnetic disk 204c and controlling the position of the data magnetic head 205a. In addition, the motor 20 supported by the base 201
3 is a plurality of 3.5-inch diameter magnetic disks 204a, 204b, 204c mounted on the spindle 202,
Rotate 204d and 204e. Next, in accordance with the signal from the write / read circuit 210, the designated predetermined magnetic head 204a is selected, the head position of the designated area is detected, and then the data signal on the magnetic disk 205d is read. This reading is performed by the data magnetic head 205a connected to the write / read circuit 210 exchanging signals with the magnetic disk 204d. The read data is converted into a predetermined signal,
It is sent to the upper device 212.

Embodiment 1 Next, as a first embodiment of the present invention, a magnetoresistive head which can be used in the magnetic disk device of FIG. 8 will be described with reference to FIG. As can be seen from FIG. 5, the magnetoresistive head of the present embodiment has a non-magnetic substrate 10, a lower shield film 17 formed on the substrate, and a lower gap film formed on the lower shield film 17. 19 and. The magnetic domain control film 1 is formed on the lower gap film 19.
2 is formed, and a magnetoresistive effect (MR) film 11 is further laminated thereon. A shunt film 14 and a soft film (hereinafter referred to as a SAL film) are formed on the MR film 11.
And 15 are formed. A signal extracting electrode 16 is formed at a predetermined location on the soft film 15 at a predetermined interval, and an upper gap film 20, a protective film 21, and an upper magnetic shield film 18 are further formed thereon. Has been formed.

Next, the manufacturing procedure of the magnetoresistive head of this embodiment and the materials forming each film will be described.
A permalloy of 1 μm was formed as a lower shield film 17 by sputtering on a non-magnetic substrate 10 on which an insulating layer such as alumina was formed into a thin film and precision-polished. After patterning using a photolithography technique, an alumina insulating film having a thickness of 0.2 μm is formed as a lower gap film 19.
A film was formed. On top of that, a film thickness of 0.1 is formed as the magnetic domain control film 12.
A NiO film having a thickness of 0.02 μm was formed on the NiO film having a thickness of 0.02 μm as an MR film 11 on the NiO film, and the angle was 90 ° from the track width direction.
It was manufactured while applying a DC magnetic field of 40 Oe in the direction of.

Next, Nb of 0.0 is formed as the shunt film 14.
A Ni—Fe—Cr alloy having a thickness of 1 μm and a Ni—Fe—Cr alloy thickness of 0.02 μm was prepared. This structure is called a composite bias system that combines a shunt bias system and a soft film (SAL) bias system, and is a structure for applying a magnetic bias to the MR film 11. Next, by using a photolithography technique, the shunt film 14, the SAL film 15, the MR film 11 and the magnetic domain control film 12 are patterned so that the width from the air bearing surface side (hereinafter referred to as element height) is 3 μm. Then, the lower gap film 19 was patterned.

Further, on the SAL film 15, Nb 0.
An electrode 16 made of 06 μm, Au 0.13 μm, and Cr 0.02 μm was produced by lift-off. At that time, the distance between the electrodes (the distance between the inner edges) was set to 3.6 μm. An upper gap film 20 having a film thickness of 0.2 is formed thereon.
A protective film 2 is formed by forming and patterning a μm alumina insulating film.
After forming a resist having a film thickness of 1 μm as 1
An upper shield film 18 of m permalloy was formed and patterned. A photolithography technique was used for patterning the upper gap film 20 and the upper shield film 18. After the formation of all films, the magnetic domain control film 12 is applied while applying a DC magnetic field of 3 kOe in the track width direction.
The NiO forming the magnetic domain control film 12 is subjected to heat treatment at 275 ° C. higher than the Neel point for 30 minutes.
Magnetic anisotropy was added to iO.

The anisotropic magnetic field of the MR film and the exchange coupling magnetic field of the MR film and the magnetic domain control film of the sample manufactured with the same film thickness as the head were 5 Oe and 40 Oe, respectively, and the magnetic field was the same as that of the head. The effective anisotropic magnetic field of the laminated film of the anisotropy-provided MR film and magnetic domain control film was 35 Oe.

In this embodiment, the upper and lower shield films 17 and 18 are provided in order to obtain a head with high resolution.
It may not be provided if high resolution is not required. Shunt film 14 as means for applying magnetic bias
The soft film 15 is required unless a means for determining the sign of the magnetic field from the medium is provided, and other bias methods such as the shunt method and the soft film bias method may be used in addition to the composite bias method. In addition, the MR film 11
If it can be formed flat, it is not always necessary to make it from the magnetic domain control film, and it may be made from the electrode. Further, in the magnetic domain control film, in addition to NiO, FeMn, FeM
An antiferromagnetic material in which Ru, Rh, Ti, or Cr is added to n can be used.

With respect to the magnetoresistive head of this embodiment manufactured as described above, coercive force of 1600 Oe, magnetic film thickness tmag = 20 nm, product of residual magnetic flux density Br and magnetic film thickness Br.tmag = 180 G.multidot. μm Co-Ta-
A recording pattern recorded at 5 kFCI by using an induction type thin film magnetic head having an overwriting characteristic of 32 dB on a Cr-based sputter medium was used, and the flying height was 0.14 μm and the sense current was 7
Reproduction was performed at × 10 ⁶ A / cm ² , and the reproduction output was evaluated.
For comparison, the head structure is the same, and the magnetic anisotropy directions of the MR film and the magnetic domain control film are both given in the track width direction.
An R head was also manufactured and the same evaluation was performed. The results are shown in Table 1.
Shown in. As can be seen from Table 1, the magnetoresistive head of this example has a smaller effective anisotropic magnetic field, a larger reproduction output voltage, and higher sensitivity and higher output than the comparative example. Neither Barkhausen noise was observed.

Embodiment 2 As shown in FIGS. 6 and 4, the magnetoresistive head of this embodiment weakens the exchange coupling between the magnetic domain control film 12 and the MR film 11 of the first embodiment. In addition, the magnetic thin film 13 is further provided. As the magnetic thin film 13, 0.01 μ
The Fe-Ni-Nb alloy thin film having a thickness of m is used as the magnetic domain control film 1.
After the film formation of No. 2, it was formed by sputtering using a Fe-Ni-Nb based alloy target. After that, the MR film 11 was produced. An MR head was manufactured in the same manner as in Example 1 with respect to the film thickness, the direction of magnetic anisotropy and other structures.

The effective anisotropic magnetic field of the laminated film of the magnetic domain control film 12, the magnetic thin film 13 and the MR film 11 of the sample produced with the same film thickness and magnetic anisotropy as the head of this embodiment is 8 Oe.
And was lower than in Example 1. .

Since the magnetic thin film 13 has a role of weakening the exchange coupling magnetic field, the saturation magnetization is smaller than that of the MR film 11, and the temperature at which the magnetization disappears is the MR film 11 and the magnetic domain control film 12.
The temperature is higher than the temperature at which the exchange coupling of the MR film disappears.
In order to allow more current to flow, the MR film 11
It is required that the specific resistance is larger than that and the magnetoresistive effect is small. In the present embodiment, the Fe-Ni-Nb type alloy was used, but materials such as Fe-Ni-Cr type alloy and Ni can also be used.

Regarding the manufactured magnetoresistive head,
Table 1 shows the results of the same evaluations as in Example 1. As can be seen from Table 1, in the magnetoresistive head of this example, the effective anisotropic magnetic field was 1/5 or less of the comparative example, and the reproduction output voltage was 5 times or more that of the comparative example. Barkhausen noise was not observed as in Example 1.

Example 3 Next, as a third example of the present invention, a Co—Ni alloy was used as the material of the MR film 11, and the film thickness, the direction of magnetic anisotropy and other structures were implemented. A magnetoresistive head was manufactured in the same manner as in Example 1. The anisotropic magnetic field of the MR film and the exchange coupling magnetic field of the MR film and the magnetic domain control film produced with the same film thickness as the head are 25 Oe and 35 Oe, respectively, and the MR film provided with the magnetic anisotropy like the head. The effective anisotropic magnetic field of the laminated film of the magnetic domain control film was 10 Oe.

Regarding the manufactured magnetoresistive head,
Table 1 shows the results of the same evaluations as in Example 1. As can be seen from Table 1, in the magnetoresistive head of this example, the effective anisotropic magnetic field was 1/4 or less of the comparative example, and the reproduction output voltage was 6 times or more that of the comparative example. Barkhausen noise was not observed.

Fourth Embodiment Next, as a fourth embodiment of the present invention, a magnetoresistive head of another embodiment having the same structure as the second embodiment shown in FIG. 6 will be described. In the magnetoresistive head of this embodiment, a Co—Pt-based alloy is used as the magnetic domain control film 12.
A Co-Ni alloy film is used as the MR film.
The other structure is the same as that of the second embodiment, and the description thereof is omitted.

A procedure for manufacturing the magnetoresistive head of this embodiment will be described. On the non-magnetic substrate 10 on which an insulating layer such as alumina was formed into a thin film and precision-polished, a lower shield film 17 was sputtered with 1 μm of permalloy.
m formed. Patterning using photolithography technology
Then, the gap film 19 having a thickness of 0.2 μm was formed. As the magnetic domain control film 12, a Co—Pt-based alloy having a film thickness of 0.03 μm was sputtered, and a DC magnetic field of 10 kOe was applied in the track width direction for magnetization. On top of that, a Fe—Ni—Nb type alloy thin film as a magnetic thin film 13 is formed to a thickness of 0.02 μm by sputtering to weaken the exchange coupling, and further an MR film 11 of C having a thickness of 0.02 μm is formed.
4 o-Ni alloy in 90 ° direction from the track width direction
It was manufactured while applying a DC magnetic field of 0 Oe. Next, a magnetic bias applying means by the composite bias method, that is, Nb of 0.01 μm as the shunt film 14 and the SAL film 1 are used.
As No. 5, a Ni—Fe—Cr alloy having a thickness of 0.02 μm was prepared. Using a photolithography technique, first, the structure for applying a bias, the MR film and the magnetic domain control film were patterned so that the element height was 3 μm, and then the gap film was patterned. On the SAL film 15, the distance between the electrodes is 3.
Nb 0.0 by lift-off so as to be 6 μm.
An electrode 16 made of 6 μm, Au 0.13 μm, and Cr 0.02 μm was produced. A gap film 20 having a film thickness of 0.2 μm is formed and patterned to form a protective film 21 having a film thickness of 1 μm.
After forming a resist having a thickness of m, an upper shield film 18 made of permalloy having a thickness of 1 μm was formed and patterned. A photolithography technique was used for patterning the gap film 20 and the upper shield film 18.

An MR formed with the same film thickness as the head
The anisotropic magnetic field of the film and the exchange coupling magnetic field of the MR film and the magnetic domain control film are 25 Oe and 80 Oe, respectively, and a Fe—Ni—Nb alloy 0.02 μm is inserted between them to obtain the same magnetic anisotropy as the head. The effective anisotropic magnetic field of the laminated film having the directionality was 10 Oe.

In this embodiment, the upper and lower shield films are provided in order to obtain a head with high resolution, but they may not be provided if high resolution is not required. When the shield film is not provided, the permanent magnet film can be magnetized after the head is manufactured. As described in the first embodiment, the means for applying the magnetic bias is necessary unless the means for judging the sign of the magnetic field from the medium is provided, and in addition to the composite bias method, the shunt method and the soft film bias. Other biasing schemes such as schemes may be used. Regarding the manufacturing order of the magnetic domain control film, the MR film and the electrode, since the permanent magnet film is conductive unlike NiO, the structure under the electrode may be the MR film, the third magnetic thin film or the permanent magnet film. It is possible, and if the MR film can be formed flat, it can be manufactured from the electrode. Further, for the magnetic domain control film, a permanent magnet film such as a Co—Pt—Cr alloy or a Co—Cr alloy can be used in addition to the Co—Pt alloy.

Regarding the manufactured magnetoresistive head,
Table 1 shows the results of the same evaluations as in Example 1. As can be seen from Table 1, in the magnetoresistive head of this example, the effective anisotropic magnetic field was 1/4 or less of the comparative example, and the reproduction output voltage was 6 times or more that of the comparative example. Barkhausen noise was not observed.

[0039]

[Table 1]

As described above, the first to fourth embodiments described above are used.
Since the magnetoresistive head described in 1) has high reproduction sensitivity, it can be reproduced with high sensitivity even when the recording density of the recording medium is increased. Therefore, the magnetic disk device equipped with the magnetoresistive head provided by the present embodiment can realize a magnetic disk device having the same size as the conventional one and a large storage capacity. Further, since the storage density can be increased, the recording medium can be downsized in the case of the same storage capacity as the conventional one, so that a small magnetic disk device can be realized.

[0041]

According to the present invention, the magnetic domain control film and the MR film are laminated even between the electrodes, which are the magnetically sensitive portions of the magnetoresistive head, to control the magnetic domain structure, and the magnetic domain control film and the MR film are mutually controlled. By giving magnetic anisotropy in another direction to reduce the effective anisotropic magnetic field, a high output magnetoresistive head without Barkhausen noise can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram illustrating that magnetic anisotropy is applied to a magnetic domain control film and an MR film in different directions in a magnetoresistive head of the present invention.

FIG. 2 is an effective anisotropic magnetic field Hk ′ and an exchange coupling magnetic field He.
FIG.

FIG. 3 is a graph showing the relationship between the reproduction output of the magnetoresistive head and the effective anisotropic magnetic field.

FIG. 4 is an explanatory diagram showing a structure used to weaken exchange coupling by disposing a magnetic thin film when the exchange coupling magnetic field between the magnetic domain control film and the MR film is large.

FIG. 5 is a perspective view of a magnetoresistive head according to an embodiment of the present invention with a main portion cut away.

FIG. 6 is a perspective view of a magnetoresistive head according to another embodiment of the present invention with a main portion cut away.

FIG. 7 is an explanatory diagram illustrating a state in which magnetic anisotropy is applied to the magnetic domain control film and the MR film in the same direction in the conventional magnetoresistive head.

FIG. 8 is an explanatory diagram showing a configuration of a magnetic disk device according to an embodiment of the present invention.

[Explanation of symbols]

11 ... MR film, 12 ... Domain control film, 13 ... Third magnetic thin film, 14 ... Shunt film, 15 ... SAL film, 16 ... Electrode,
17 ... Lower shield film, 18 ... Upper shield film, 19,
20 ... Gap film, 21 ... Protective film.

Claims (13)

[Claims] 1. A substrate, a magnetoresistive film having uniaxial magnetic anisotropy on the substrate, and a magnetic domain control film having uniaxial magnetic anisotropy and controlling magnetic domains of the magnetoresistive film. And a magnetoresistive head having a pair of electrodes for passing a current through the magnetoresistive film, wherein the magnetic domain control film is laminated with the magnetoresistive film at least between the pair of electrodes, and A magnetic continuity with the magnetoresistive effect film at their interface, and the magnetoresistive effect film has an easy magnetization axis in a direction different from the easy magnetization axis of the magnetic domain control film. A magnetoresistive head. 2. The magnetic thin film according to claim 1, further comprising a magnetic thin film for adjusting a magnetic domain control effect of the magnetic domain control film with respect to the magnetoresistive effect film, the magnetic thin film including the magnetoresistive effect film and the magnetic domain control film. A magnetoresistive head, which is disposed between the magnetoresistive film and the magnetoresistive film, and has magnetic continuity at an interface with the magnetoresistive film and an interface with the magnetic domain control film. 3. The magnetoresistive head according to claim 1, wherein the magnetic domain control film has an easy axis of magnetization in a direction of a distance between the pair of electrodes. 4. The magnetoresistive head according to claim 1, wherein the magnetic domain control film is made of an antiferromagnetic material or a permanent magnet material. 5. The magnetoresistive head according to claim 2, wherein the saturation magnetization of the magnetic thin film is smaller than that of the magnetoresistive film. 6. The film according to claim 1, further comprising a film used to apply a magnetic bias to the magnetoresistive film in a direction orthogonal to a direction of a current flowing through the magnetoresistive film. A magnetoresistive head. 7. The magnetoresistive effect film according to claim 1, wherein the magnetoresistive effect film is a Fe—Ni based alloy, a Co—Ni based alloy, and a Fe—
A magnetoresistive head, comprising any one of Ni-Co alloys. 8. The magnetic domain control film according to claim 1, wherein the magnetic domain control film is N.
A magnetoresistive head comprising iO. 9. The magnetic thin film according to claim 2, wherein the magnetic thin film is Fe.
A magnetoresistive effect magnetic head characterized by comprising a Ni-Nb alloy. 10. The magnetic anisotropy synthesized by stacking the magnetoresistive effect film and the magnetic domain control film according to claim 1, wherein a component of an anisotropic magnetic field in a space direction of the pair of electrodes is An anisotropic magnetic field of the magnetoresistive film,
A magnetoresistive head, which is smaller than a sum of an exchange coupling magnetic field acting between the magnetoresistive film and the magnetic domain control layer. 11. A substrate, a magnetoresistive film having uniaxial magnetic anisotropy on the substrate, and a magnetic domain control film made of an antiferromagnetic material for controlling the magnetic domain of the magnetoresistive film. A method of manufacturing a magnetoresistive effect head having a pair of electrodes for supplying a current to the magnetoresistive effect film, wherein the magnetoresistive effect film is formed on the substrate while applying a magnetic field, The magnetic domain control film is laminated on the magnetoresistive film, and the magnetoresistive film is formed on the magnetic domain control film while heating the magnetic domain control film to the Neel temperature of the antiferromagnetic material or higher. A method of manufacturing a magnetoresistive head, wherein a DC magnetic field larger than the anisotropic magnetic field of the magnetoresistive film is applied in a direction different from the magnetic field at that time. 12. A substrate, a magnetoresistive effect film having uniaxial magnetic anisotropy on the substrate, a magnetic domain control film which is made of a permanent magnet material and controls a magnetic domain of the magnetoresistive effect film, A method of manufacturing a magnetoresistive head having a pair of electrodes for flowing a current through the magnetoresistive film, wherein the magnetoresistive film is formed on the substrate while applying a magnetic field, The magnetic domain control film is laminated on the resistance effect film, and then a DC magnetic field is applied to the magnetic domain control film in a direction different from the magnetic field at the time of forming the magnetoresistive effect film. Method of manufacturing magnetoresistive head. 13. A magnetoresistive head for reading a signal of a magnetic disk by using a magnetoresistive effect, a drive unit for rotating the magnetic disk, and a processing circuit for processing a signal read by the magnetoresistive head. In the magnetic disk device having, the magnetoresistive head is a substrate, and on the substrate,
A magnetoresistive effect film having a uniaxial magnetic anisotropy, a magnetic domain control film having a uniaxial magnetic anisotropy and controlling a magnetic domain of the magnetoresistive effect film, and a current flowing through the magnetoresistive effect film. A pair of electrodes, the magnetic domain control film is laminated with the magnetoresistive film at least between the pair of electrodes, and has magnetic continuity with the magnetoresistive film at the interface. The magnetic resistance effect film has an easy axis of magnetization in a direction different from the easy axis of magnetization of the magnetic domain control film.