JPH07230609A - Magneto-resistance effect type head - Google Patents

Abstract

PURPOSE:To obtain the stable reproduced output by setting the axis of easy magnetization of a magneto-resistance effect element parallel with a sense current and the axis of easy magnetization of a soft magnetic layer perpendicular to the sense current. CONSTITUTION:This magnetic head consists of the MR element 1, an intermediate layer 2 and the soft magnetic layer 3. These films are laminated in this order. The axis 1A of easy magnetization of the MR element 1 is parallel with the Z direction where the sense current flows and the axis 3A of easy magnetization of the soft magnetic layer 3 is perpendicular to a Z direction and an X direction. The MR element 1 is formed by a sputtering method, etc., and a magnetic field is previously impressed in the Z direction in such a manner that the axis 1A of easy magnetization of the MR element 1 is paralleled with the Z direction in order to produce the respective films. In succession, the intermediate layer 2 is formed on the MR element 1 and the soft magnetic layer 3 is formed thereon. At this time, the magnetic field is previously impressed in the Y direction in such a manner that the axis 3A of easy magnetization is paralleled with the Y direction. As a result, the direction of magnetization of the soft magnetic layer 3 is no longer fluctuated and the output of the MR head is stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive head (MR head) used in a magnetic recording / reproducing device such as a magnetic disk device or a magnetic tape device.

In recent years, with the increase in capacity of magnetic recording / reproducing devices used as external storage devices of computers, high-performance magnetic heads have been required. In order to satisfy this requirement, an MR that can obtain a high output without depending on the speed of the recording medium and can be used for a small-diameter disc.
The head is receiving attention.

[0003]

2. Description of the Related Art Conventionally, as shown in FIG.
An MR head in which a magnetoresistive effect element (MR element) 1 is in contact with a soft magnetic layer 3 via an intermediate layer 2 is known.

The MR element 1, the intermediate layer 2 and the soft magnetic layer 3 are laminated and patterned into a rectangular shape.
The easy axis of magnetization of the soft magnetic layer 3 is parallel to the longitudinal direction of the pattern. In the following description, the stacking direction of each layer is the X direction, the longitudinal direction of the pattern is the Z direction, and the direction perpendicular to the X direction and the Z direction is the Y direction.

Reference numeral 4 is a lead conductor for passing a sense current. The lead conductor 4 is electrically joined to the soft magnetic layer 3 at a predetermined width interval in the longitudinal direction of the soft magnetic layer 3 to define a signal detection region 5, and a sense current is detected by the sense current through the lead conductor 4. It flows into area 5.

When a signal magnetic field from a recording medium (not shown) moving in the X direction enters the signal detection area 5, the signal detection area 5
The electric resistance of the MR element 1 changes in, and the voltage across the MR element 1 changes. And this voltage change is this M
It is detected as the output of the R head.

Here, in order that the resistance of the MR element 1 changes linearly with respect to the signal magnetic field from the opposing recording medium, M
The magnetization of the R element 1 is inclined by receiving a bias magnetic field from the soft magnetic layer 3. This state is shown in FIG.

When a sense current flows in the direction of arrow 6, the magnetization of the soft magnetic layer 3 is saturated perpendicularly to the sense current by the magnetic field generated by this current, as indicated by arrow 7. Then, the magnetic field (arrow 8) generated by this saturation magnetization causes the magnetization of the MR element 1 to be inclined by approximately 45 ° with respect to the Z direction as shown by arrow 9.

[0009]

When the axis of easy magnetization of the soft magnetic layer 3 is parallel to the sense current as in the prior art, even if the magnetic field of the sense current saturates the magnetization of the soft magnetic layer 3 in the Y direction. In some cases, the direction of magnetization of the soft magnetic layer 3 is changed by the magnetic field from the recording medium, and the magnetic bias applied to the MR element 1 may become unstable.

When the magnetic bias applied to the MR element 1 becomes unstable, the reproduction output of this MR head becomes unstable, which is a practical problem. Therefore, an object of the present invention is to provide an MR head that can obtain a stable reproduction output.

[0011]

According to the present invention, in a magnetoresistive head having a magnetoresistive element in contact with a soft magnetic layer via an intermediate layer, the easy axis of magnetization of the magnetoresistive element is sensed. There is provided a magnetoresistive head which is parallel to a current and has an axis of easy magnetization of the soft magnetic layer perpendicular to a sense current.

[0012]

According to the present invention, since the easy axis of magnetization of the soft magnetic layer is perpendicular to the sense current, the magnetization of the soft magnetic layer in the signal detection region is sensed when the sense current is passed through the signal detection region. Saturation tends to occur in the direction perpendicular to the current, the magnetization of the soft magnetic layer becomes stable with respect to the magnetic field from the recording medium, and the reproduction output of the MR head becomes stable.

[0013]

EXAMPLES Examples of the present invention will be described in detail below. Figure 1
FIG. 3 is a perspective view of a main part of the MR head showing the first embodiment of the present invention. In this figure, the drawing of the lead conductor 4 shown in FIG. 3 is omitted.

The MR element 1, the intermediate layer 2 and the soft magnetic layer 3 are
For example, each of them is composed of a NiFe film, a Ta film, and a NiFeCr film, and these films are laminated in this order to maintain an electrically joined state. The easy axis 1A of the MR element 1 is parallel to the Z direction, which is the direction in which the sense current flows, and the easy axis 3A of the soft magnetic layer 3 is perpendicular to the Z and X directions.

As a method for producing each film, a usual sputtering method can be adopted. In this case, for example, the MR element 1 is first formed on a head substrate (not shown). At the time of this film formation, a magnetic field is applied in the Z direction so that the easy axis 1A of the MR element 1 is parallel to the Z direction.

Subsequently, after forming the intermediate layer 2 on the MR element 1, the soft magnetic layer 3 is formed thereon. When forming the soft magnetic layer 3, a magnetic field is applied in the Y direction so that the easy axis of magnetization 3A is parallel to the Y direction.

According to this embodiment, since the easy axis of magnetization 3A of the soft magnetic layer 3 is set to be perpendicular to the sense current, the direction of magnetization of the soft magnetic layer 3 changes according to the principle of the present invention described above. The output of this MR head becomes stable.

FIG. 2 is a perspective view of the main part of an MR head showing a second embodiment of the present invention. This embodiment corresponds to the first of FIG.
In comparison with the embodiment, the magnetic film 10 is further provided, which is magnetically coupled to the soft magnetic layer 3 to generate an exchange bias magnetic field H _UA in the same direction as the easy axis 3A of the soft magnetic layer 3. Attached.

When the exchange bias magnetic field H _UA goes from bottom to top in the Y direction as shown, the sense current flows from right to left in the Z direction. on the other hand,
Although not shown, when the exchange bias magnetic field H _UA is from top to bottom in the Y direction, the sense current flows from left to right in the Z direction.

According to this embodiment, the magnetic domain of the soft magnetic layer 3 is controlled by the exchange bias magnetic field generated by the magnetic film 10, and the stabilization of the magnetization of the soft magnetic layer 3 becomes more remarkable. The magnetic film 10 is an antiferromagnetic film made of FeMn or the like, a permanent magnet film made of CoCrTa or the like, or Tb.
A ferrimagnetic film made of Co or the like can be used.

[0021]

As described above, according to the present invention,
As a result, it becomes possible to provide a magnetoresistive head capable of obtaining a stable reproduction output.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a magnetoresistive head showing a first embodiment of the present invention.

FIG. 2 is a perspective view of a main part of a magnetoresistive head showing a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 1 Magnetoresistive effect element (MR element) 2 Intermediate layer 3 Soft magnetic layer 4 Lead conductor 10 Magnetic film

Claims (2)

[Claims] 1. A magnetoresistive head comprising a magnetoresistive element (1) in contact with a soft magnetic layer (3) via an intermediate layer (2), wherein the magnetoresistive element (1) is easily magnetized. A magnetoresistive head having an axis parallel to the sense current and an axis of easy magnetization of the soft magnetic layer (3) perpendicular to the sense current. 2. A magnetic film (10) which is magnetically coupled to the soft magnetic layer (3) to generate an exchange bias magnetic field in the same direction as the easy axis of the soft magnetic layer (3). Item 1. The magnetoresistive head according to Item 1.