JPH04182907A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain the magnetic head which hardly forms a pseudo magnetic gap by providing three layers; a layer of a soft magnetic film which contains at least nitrogen, a layer of a soft magnetic film which does not contain the nitrogen and a layer of a soft magnetic film which contains the nitrogen in the section where the soft magnetic films come into contact with ferrite. CONSTITUTION:The three layers; the layer 14 of the soft magnetic film which contains the nitrogen, the layer 15 of the soft magnetic film which does not contain the nitrogen and the layer 13 of the soft magnetic film which contains the nitrogen are provided in the section where the soft magnetic films come into contact with the ferrite at the head of an MIG type disposed with the soft magnetic films in the gap part of the ferrite cores. The nitrogen ligther than metal atoms diffuses from the nitrided layer 14 adjacent to the ferrite 12 further to the non-nitrided layer 15 adjacent thereto at the time of the heat treatment for gap formation. If the non-nitrided layer 15 pinched by the nitrided layer 14 is as thin as the nitrided layer 14, the compsn. of the metal is larger in the non-nitrided layer 15 by as much as the nitrogen-content and, therefore, the concn. of the nitride of the metal of the initial non-nitrided layer 15 is sufficiently larger than the concn. of the nitride of the metal of the first nitrided layer 14 and this nitride completely suppresses the diffusion of the elements, such as oxygen, from the ferrite 12. The influence of the pseudo gap is suppressed in this way and the degradation of the head magnetic characteristics is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic head, and particularly to a so-called MIG type magnetic head in which a magnetic material having a high saturation magnetic flux density and high magnetic permeability is arranged in a magnetic gap portion.

Conventional technology In recent years, advances in video, audio, and information-related equipment have been remarkable.

The mainstream of recording in these fields is magnetic recording, and due to the strong demand for higher recording densities, efforts are being made to develop high-coercive metal media and magnetic heads with sufficient recording capacity to meet these demands. It is progressing.

Regarding magnetic heads, a wide variety of magnetic heads using materials such as Sendust, Co-based amorphous, and Fe-based alloys having high saturation magnetic flux density have been developed, and some of them have already been put into practical use. Among these, the so-called parallel gear type MrG head, which has a main core made of magnetic ferrite and a metal magnetic film with high saturation magnetic flux density and high magnetic permeability formed parallel to the gap, is comparatively Although it has the advantage of having a simple structure and high productivity, it is difficult to put it into practical use because it generates false signals due to the generation of a false gap at the interface between the ferrite and metal film due to reaction and diffusion during heat treatment. It was difficult. Therefore, in recent years, research has been carried out on metal films and nonmagnetic reaction prevention films that have less reaction with ferrite and diffusion, and parallel gap type MIG heads are also being put into practical use.

(For example, Journal of the Japanese Society of Applied Magnetics J12.103-10
6 (1988) or “Journal of the Japanese Society of Applied Magnetics J13.
277-280 (1989)) Problems to be Solved by the Invention However, in the above-mentioned parallel gear type MIG head,
When using a metal film with low reaction and diffusion with ferrite, it is possible to directly apply metal magnetic films with high saturation magnetic flux density and high magnetic permeability that have already been developed and are used in other types of magnetic heads. Therefore, a new composition suitable for this purpose must be developed. Further, when a non-magnetic reaction prevention film is used, the non-magnetic film itself becomes a gap, so there is a problem in that the generation of pseudo gaps cannot be completely suppressed.

In view of the above-mentioned problems, the present invention applies a metal magnetic film with high saturation magnetic flux density and high magnetic permeability that has already been put into practical use directly to a parallel gear type MIG head that has a simple structure and high productivity. The present invention provides a magnetic head that generates almost no energy.

Means for Solving the Problems In order to solve the above problems, the magnetic head of the present invention is an MIG type head in which a soft magnetic film is disposed on the cap portion of a ferrite core, in which the soft magnetic film is in contact with the ferrite. The structure is such that at least three layers are provided on the Buerite side: a layer of a soft magnetic film containing nitrogen, a layer of a soft magnetic film not containing nitrogen, and a layer of a soft magnetic film containing nitrogen.

According to the present invention, with the above-described configuration, during heat treatment for forming a gap, nitrogen atoms, which are lighter than metal atoms, first diffuse from the nitrided layer adjacent to the ferrite to the non-nitrided layer adjacent to the ferrite. Next, if the non-nitrided layer sandwiched between the nitrided layers is as thin as the nitrided layer adjacent to the ferrite, the non-nitrided layer originally has a higher metal composition by the amount of nitrogen, so The metal nitride concentration of the layer becomes sufficiently high compared to the metal nitride concentration of the initial nitrided layer that it completely suppresses the diffusion of elements such as oxygen from the ferrite. Therefore, diffusion from ferrite is limited to at most the first nitrided layer, and it is extremely difficult for elements such as oxygen to diffuse into this already nitrided layer.

That is, by using a nitrided layer and a non-nitrided layer in combination, the diffusion of elements between the soft magnetic film and the ferrite is suppressed, thereby suppressing the effects of the pseudo gap and preventing deterioration of head characteristics. It will be.

Embodiments Embodiment 1 A magnetic head according to a first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing the vicinity of the gap between the sliding surface and the magnetic recording medium of a MIG type magnetic head according to the present invention in which a nitrogen-free soft magnetic film is disposed on the cap portion of a ferrite core; The figure is a plan view showing the vicinity of the gap between the sliding surface and the magnetic recording medium of a MIG type magnetic head according to the present invention in which a soft magnetic film containing nitrogen is disposed on the cap of a ferrite core. FIG. 4 is a plan view showing the vicinity of the gap between the sliding surface and the magnetic recording medium of a MIG type magnetic head in which a metal magnetic film with high saturation magnetic flux density and high magnetic permeability is directly arranged on the cap part of a ferrite core. The figure shows the vicinity of the gap between the sliding surface and the magnetic recording medium of a MIG type magnetic head in which a nitrogen-free soft magnetic film is placed on the cap of a ferrite core through only one nitride layer. FIG.

1st. Second. Third. In FIG. 4, 11 is a main gap, 12 is a ferrite core, and 16 is a molded glass. In addition, in FIG. 1, 13 is CoNbZr and F
eAeSi, 14 is CoNbZrN and FeA1! S
iN, 15 is the same as 13, and in Fig. 2, 13
is FeNbN, 14 is the same as 13, 15 is FeNb, and in Fig. 3, 13 is CoNbZr, FeAeS.
i and FeNbN, and in FIG. 4 13 is Co
NbZr and FeAQ Si, 14 is CoNbZrN
and FeAf! It is SiN. In the first embodiment, the thickness of the soft magnetic film 13 in FIGS. 1 to 4 is 4.2 mm.
μm, and the thickness of one layer of the nitrided layer 14 and the non-nitrided layer 15 is 2
70 people, nitrogen content in nitride layer 14 is approximately 9% in atomic percent
, the magnetic gap formation temperature is 550°C.

Regarding the magnetic head configured as described above, the following describes the first part.
Explain its characteristics using a table.

Table 1 shows the magnetomotive force 550 of each magnetic head shown in Figures 1 to 4 when the relative speed between the head and the magnetic recording medium (metal powder coated tape) is 3.1 m/s.
It shows the pseudo output (ratio of the output vG in the pseudo gap to the output vM in the main gap) and the waviness of the frequency characteristics at mA-turn and a writing frequency of 65 kHz.

(Margins below) From Table 1, it can be seen that compared to the conventional head with the configuration shown in Figure 3, the head that combines the nitrided layer and non-nitrided layer of the present invention has
It can be seen that the influence of the pseudo gap has become smaller.

In addition, if the soft magnetic film disposed in the gap part does not contain nitrogen, simply add a nitride layer to the surface where the soft magnetic film and ferrite are in contact.
Rather than providing only one layer, three layers of nitrided layer, non-electrified layer, and nitrided layer are used.
It can be seen that the effect of the pseudo gap is smaller when the layer is provided.

When the above head is cut parallel to the gap plane at the surface of the soft magnetic film near the ferrite and analyzed using Auger electron spectroscopy, it is found that in the head with only one nitride layer, the oxygen in the ferrite exceeds the nitride layer. In contrast, in a head with three layers: a nitrided layer, a non-electrified layer, and a nitrided layer, the oxygen in the ferrite does not diffuse into the non-nitrided layer.
The absolute amount of oxygen diffused is also small.

As described above, according to this embodiment, by using a combination of a nitrided layer and a non-nitrided layer, a metal magnetic film with high saturation magnetic flux density and high magnetic permeability that has already been put into practical use can be used as is.
Even when applied to a parallel gear type MIG head, which has a simple structure and high productivity, it is possible to suppress the diffusion of elements between the soft magnetic film and the ferrite, thereby providing a MIG head with a small influence of pseudo gaps.

Example 2 A second example of the present invention will be described below with reference to FIG. 1 and Table 2.

Table 2 shows the diffusion of elements at 550°C when the thicknesses of the nitrided layer 14 and the non-nitrided layer 15 are changed in a head using CoNbZr as the soft magnetic film 3 in Figure 1. This is the result of analyzing the situation using Auger electron spectroscopy. In the table, ○ indicates that the diffusion of the element is hardly visible, △ indicates that it is only slightly visible, and × indicates that a considerably large amount of element diffusion is observed.

Table 2 From Table 2, the thickness A of the layer containing nitrogen and the thickness B of the layer not containing nitrogen are in the ranges of 50 Å < A < 100 OA and 50 Å < B < 1000 Å, respectively. It can be seen that in some cases the diffusion between the soft magnetic film and the ferrite is very low.

Example 3 A third example of the present invention will be described below with reference to FIG. 1 and Table 3.

Table 3 shows the state of element diffusion at 550°C when the nitrogen concentration of the nitride layer 14 is changed in a head using CoNbZr as the soft magnetic film shown in Figure 1. This is the result of analysis using spectroscopy. In the table, ○ indicates that the element diffusion is hardly visible, △ indicates that it is only slightly visible, and × indicates that a considerably large amount of element diffusion is observed.

From Table 3, it can be seen that the nitrogen concentration C of the nitrided layer is 3%<3% in atomic %.
It can be seen that when A<50%, the diffusion between the soft magnetic film and the ferrite becomes very small.

Note that in the first embodiment, the soft magnetic film 13 is made of CoNbZ.
r, FeAe Si or FeNbN, but Co-
M (M=Nb, Ta, Z r, T i .

Other Co-based amorphous materials such as Hf, B, Si, Ga) and Fe-M-3i (M=Ae, Ga, Ru
) or other sendust alloys such as F e -M (M-
Ti, Zr, B, Hf, Nb, Ta, Ae, Mo),
Fe-M-C (M=TI, Zr, Hf-, V, Nb.

Other iron-based alloys such as Ta) and Fe-N may also be used. Also the second
．． In the third embodiment as well, the soft magnetic film 13 is made of CoNbZr, but other soft magnetic films may be used as well.

Effects of the Invention As described above, the present invention provides a MIG type head in which a soft magnetic film containing nitrogen is disposed on the cap portion of a ferrite core, in which the soft magnetic film is in contact with the ferrite, at least in order from the ferrite side. A MIG type head in which two layers are provided, a layer of a soft magnetic film containing nitrogen and a layer obtained by removing only nitrogen from the soft magnetic film, or a soft magnetic film not containing nitrogen is placed on the cap portion of a ferrite core. At the part where the soft magnetic film is in contact with the ferrite, in order from the ferrite side, a nitrided layer of the soft magnetic film, a layer of the soft magnetic film not containing nitrogen, and a nitrided layer of the soft magnetic film are applied.
By having a structure of providing layers, it is possible to create a parallel gear type Mr with a simple structure and high productivity by using a metal magnetic film with high saturation magnetic flux density and high magnetic permeability that has already been put into practical use.
It is possible to provide a magnetic head that can be applied to a G head and generates almost no pseudo gap.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the vicinity of the gap between the sliding surface of a MIG type magnetic head in which the nitrogen-free soft magnetic film of the present invention is disposed on the cap of a ferrite core, and the sliding surface between the magnetic recording medium and the magnetic recording medium. A plan view showing the vicinity of the gap between the sliding surface and the magnetic recording medium of a MIG type magnetic head in which the nitrogen-containing soft magnetic film of the present invention is disposed on the cap portion of the ferrite core;
Figure 3 shows an MIG in which a conventional metal magnetic layer with high saturation magnetic flux density and high magnetic permeability is placed directly on the cap of the ferrite core.
Figure 4 is a plan view showing the vicinity of the gap between the sliding surface of this type of magnetic head and the magnetic recording medium. FIG. 3 is a plan view showing the vicinity of the gap between the sliding surface of the MIG type magnetic head and the magnetic recording medium arranged therein. 11...-main gap, 12...ferrite core, 13...soft magnetic film, 14...
...Nitrided layer, 15...Non-nitrided layer, 16...
...Molded glass. Name of agent: Patent attorney Haruaki Koebi and two others Figure 1! ! Main f Ino 7゜14 Nitride layer Figure 3 tf Main key °f Tsude / Figure 4\ /l: Cage return

Claims (4)

[Claims] (1) In a MIG type head in which a soft magnetic film is arranged on the cap part of a ferrite core, at least a layer of a soft magnetic film containing nitrogen and a layer of a soft magnetic film containing nitrogen are applied to the part where the soft magnetic film contacts the ferrite, starting from the ferrite side. A magnetic head comprising three layers: a soft magnetic film layer that does not contain nitrogen, and a soft magnetic film layer that contains nitrogen. (2) The magnetism according to claim (1), wherein the thickness A of the layer containing nitrogen and the thickness B of the layer not containing nitrogen are 50 Å<A<1000 Å and 50 Å<B<1000 Å, respectively. head. (3) The nitrogen concentration C of the nitrogen-containing layer is 3%<3% in atomic %
The magnetic head according to claim 1, characterized in that C<50%. (4) The thickness A of the layer containing nitrogen and the thickness B of the layer not containing nitrogen are 50 Å<A<1000 Å and 50 Å<B<1000 Å, respectively, and the nitrogen concentration C of the layer containing nitrogen is atomic The magnetic head according to claim 1, wherein 3%<C<50%.