JPH0495205A - Magnetoresistive head - Google Patents

Abstract

PURPOSE:To prevent the corrosion of a magnetic film and to obtain the MR head having high reliability by adding Nb to the magnetic film of the magneto- resistance effect type head. CONSTITUTION:The Nb is added to the magnetic film 12 of the magneto- resistance effect type head which detects a change in magnetic field by a change in the resistance value of a magneto-resistance effect element 1 laminated with the magnetic film 12. Namely, the Nb having a corrosion presventive effect is added and the magnetic film 12 is constituted like an FeMnNb film, TbCoNb film, etc. The ratio occupied by the Nb is generally several per cents of the mass of the magnetic film and the content thereof is determined by taking the intensity of an exchange bond magnetic field, etc., into consideration. The corrosion of the magnetic film 12 to be laminated on the MR element 11 is prevented in this way.

Description

[Detailed Description of the Invention] [Summary] Regarding a magnetoresistive head, a change in the magnetic field is detected by a change in the resistance value of a magnetoresistive element in which a magnetic film is laminated, with the aim of preventing corrosion of the magnetic film. In the magnetoresistive head, Nb is added to the magnetic film.

[Industrial application field]

The present invention relates to a magnetoresistive head (hereinafter referred to as an MR head).

In recent years, with the increase in the capacity of magnetic disk drives, which are external storage devices for computers, there has been a demand for high-performance magnetic heads. An MR head that can obtain high output regardless of the speed of the recording medium is attracting attention as a device that satisfies this requirement.

[Conventional technology]

An MR head is a read-only magnetic head made of a ferromagnetic thin film (MR film), and uses the magnetoresistive effect, in which the electrical resistance of a ferromagnetic thin film made of permalloy or the like changes depending on an external magnetic field, to generate a signal magnetic field. This detects changes in electrical resistance as changes in electrical resistance. The element constituted by the ferromagnetic thin film is called a magnetoresistive element (hereinafter referred to as an MR element).

The structure of a conventional MR head is shown in Figs. 2(a) and (b). 21 is a rectangular MR element, 22 is an antiferromagnetic film (Fe
Mn) or ferrimagnetic film (TbCo) is laminated.

23 is a lead-out conductor layer, and 24a and 24b are magnetic shields. The longitudinal direction (y-axis direction) of the MR element 21 coincides with the easy axis direction of the MR film, and the laminated antiferromagnetic film (FeMn
) etc., the magnetization within the element is stably aligned in the easy axis direction, resulting in a single magnetic domain state. Note that the bias magnetic field is applied by a self-bias method.

The following measures were provided to prevent corrosion of the magnetic film.

[Means to solve the problem]

To solve the above problems, the present invention provides a magnetoresistive head that detects a change in a magnetic field based on a change in the resistance value of a magnetoresistive element 11 in which a magnetic film 12 is laminated, in which Nb is added to the magnetic film 12. It was configured to do this.

[Operation] Since Nb, which has a corrosion-preventing effect, is added, corrosion of the magnetic film 12 laminated on the MR element 11 can be prevented, and stable reproduction operation of the MR head can be expected.

[Invention or problem to be solved]

In conventional MR heads, a magnetic film (F
There was also the problem that they were easily corroded (eMn, TbCo).

Therefore, in view of this problem, an embodiment of the present invention, which is laminated to an MR element (Example), will be described with reference to the drawings.

FIGS. 1(a) and 1(b) are diagrams for explaining the present invention in detail.

FIG. 1(a) is a sectional view of a main part of the MR head of the present invention. As shown in the figure, the MR head has a structure in which an MR element 11 is placed inside a lead-out conductor layer 13 with a nonmagnetic insulating layer 15 interposed between two magnetic shields 14a and 14b.

The MR element 11 is made of a ferromagnetic material such as a NiFe film, and has a thin film structure with a thickness t of 400 to 500, and a width t2.
is set to about 3 μm. Here, the MR element 11
The shape is rectangular as shown in FIG. 1(b). Then, it is cut with a predetermined width, and the radius t and the radius t5 of the nodal rotation are
As shown in FIG. 1(b), the signal detection area 16 is connected to the lead-out conductor layer 13 having the same structure at both ends.

The MR element 11 has magnetic films 12 of the same shape stacked together.

This is to apply an exchange coupling magnetic field in the easy axis direction of the MR element 11. The film to which the exchange coupling magnetic field is applied may be an antiferromagnetic film (FeMn), a ferrimagnetic film (TbCo), a high magnetic film (NiFeCo), or the like.

These films are formed by a vapor deposition method, a sputtering method, or the like.

The thickness t is about 200 people. However, the magnetic film, such as FeMn, is easily corroded. Therefore, in the present invention, Nb, which has a corrosion-preventing effect, is added, and the magnetic film 12 is made of FeMnN.
b film, TbCoNb film, etc. As a result, corrosion of the magnetic film 12 is prevented, and the MR element 11 is made into a stable single magnetic domain. Therefore, the reproduction operation of the MR head is stable, which helps improve reliability. Note that the proportion occupied by Nb is generally several percent of the mass of the magnetic film, and its content is determined in consideration of the strength of the exchange coupling magnetic field, etc. This is because the strength of the exchange coupling magnetic field is somewhat reduced by the addition of Nb. Note that the strength of the exchange coupling magnetic field is the strongest in the ferrimagnetic film, followed by the antiferromagnetic film and the high magnetic film. FIG. 1(C) and FIG. 1(d) show modified examples of the laminated portion of the magnetic film 12 according to the present invention. In the figure, the MR element 11 is formed in an annular shape and faces the signal detection area. A magnetic film 12 is laminated at the location.As shown in the figure, the shape of the MR element and the magnetic film 12 is not limited to a rectangular shape.If the MR element 11 is made into a ring shape, it has a single magnetic domain structure due to its shape anisotropy. The same IJ (d) is shown in the same figure (C).
It is a right sectional view of the lamination|stacking location in FIG. It is sufficient that the magnetic film 12 is laminated only on one side of the MR element 11, as shown in FIG. In the figure (C), the vertical width t6 is larger than the radius t2 of the MR element 11, and the horizontal width t7 is not particularly limited as long as it does not extend to the signal detection area 16. This is because if it reaches the signal detection area 16, it will affect signal detection.

Further, the film 12 that generates the exchange coupling magnetic field is the MR element 11.
It is not necessary to stack the layers according to the curvature of. MR element 11
This is because an exchange coupling magnetic field will be generated as long as it is bonded to the material. In this way, depending on the shape of the MR element 11, the magnetic 812
need only be laminated on a portion of the layer.

The lead conductor layer 13 is made of an Au film or the like. In this embodiment, as shown in FIG. 1(b), there is a radiation t2 of the MR element 11 and a radiation t between the paths, and it is formed in a right-angled shape, but it is not limited to this shape. There isn't. This is because it is sufficient that the sense current 18 flows through the signal detection region 16. The width t4 of the signal detection area is approximately 2 to 3 μm.

The magnetic shields 14a and 14b are made of NiFe, ferrite material, or the like. These serve to enhance the reproduction resolution of the MR element 11 with respect to the signal magnetic field from the recording medium 17.

The MR element 11, the magnetic film 12 and the lead-out conductor layer 13 are
These are arranged between two magnetic shields 14a and 14b, and these are formed by a nonmagnetic insulating layer 1 of SiO□ film or Al2O* film.
It is configured to be electrically insulated from the magnetic shield via 5. The MR element 11 is arranged inside the nonmagnetic insulating layer 14. This is to avoid being influenced by external magnetic fields or external currents.

The sense current 18 flows into the signal detection region 16 of the MR element 11 through the extraction conductor layer 12. Then, as the MR operates linearly using the above-described self-bias method, the MR head detects a signal magnetic field from the magnetic recording medium 17 moving directly below. At this time, Barkhausen noise does not occur because the MR element 11 has a single magnetic domain structure according to the above-described inventive principle.

Note that in these examples, the self-bias method is used as the linearization method for MR head reproduction, and the present invention does not particularly limit the bias means for linearization. The bias method may be any other shunt bias method, permanent magnet bias method, current bias method, barber pole bias method, or the like.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to prevent corrosion of the magnetic film disposed to stabilize the reproduction operation of the MR head, and to provide a highly reliable MR head.

[Brief explanation of drawings]

FIG. 1(a) is a cross-sectional view of a main part of an MR head according to an embodiment of the present invention, FIG. 1N(b) is a perspective view of a main part of an MR element according to an embodiment of the present invention, and FIG. 1(C) is a cross-sectional view of a main part of an MR head according to an embodiment of the present invention. Figure 1(d) is a sectional view taken along the line dd in Figure 1(c), and Figure 2(d) is a diagram illustrating a modification of the arrangement of the magnetic film in
FIG. 2A is a sectional view of a main part of a conventional MR head, and FIG. 2B is a perspective view of a main part of a conventional MR element. In the figure, 11.21 is an MR element, 12.22 is a magnetic film, 13.23 is an extraction conductor layer, 14a and 24a are magnetic shields, 14b and 24b are magnetic shields, 15.25 is a non-magnetic insulating layer, 16. 26 is a signal detection area, 17.27 is a magnetic recording medium, and 18.28 is a sense current. Embodiment 1 of the present invention FIG. 18f is a sectional view of a main part of an MR head according to the first embodiment. Embodiment 1 of the present invention FIG.
b) Figure (C) 11° MR element VTl rjiT (c) qd -d ml vessel N Figure 1 (d)

Claims (3)

[Claims] (1) Magnetoresistive element (1) laminated with magnetic film (12)
1) A magnetoresistive head for detecting a change in a magnetic field by a change in resistance value, characterized in that Nb is added to the magnetic film (12). (2) Claim 1 in which the magnetic film (12) is an antiferromagnetic film.
The described magnetoresistive head. (3) The magnetoresistive head according to claim 1, wherein the magnetic film (12) is a ferrimagnetic film.