JPH01303613A - Magnetic head - Google Patents

Abstract

PURPOSE:To prevent the interdiffusion of magnetic cores and thin ferromagnetic metallic films by forming thin oxide films consisting of group 4A metals as diffusion preventive films between the magnetic cores and the thin ferromagnetic metallic films. CONSTITUTION:This magnetic head is deposited and formed with the thin ferromagnetic metallic films 3, 4 on the surfaces opposite to the magnetic gap of a pair of the magnetic cores 1, 2 consisting of a ferromagnetic metal oxide and is butted with the thin metallic films 3, 4 against each other to constitute the magnetic gap. The diffusion preventive films 7, 8 consisting of the oxide of the group 4A metals of the periodic table such as, for example, Ti and Zr are interposed to the boundaries between the ferromagnetic oxides 1, 2 and the thin ferromagnetic metallic films 3, 4. The diffusion of Fe atoms, Si atoms, and Al atoms from the thin films 3, 4 to the magnetic cores 1, 2 at the time of a high temp. and the diffusion of oxygen atoms from the cores 1, 2 to the thin films 3, 4 are surely prevented in this way.

Description

[Detailed Description of the Invention] The present invention relates to a magnetic head, and particularly to a metal-in-gap type magnetic head that uses a core made of a ferromagnetic metal oxide material and a ferromagnetic metal thin film material. It is related to the head.

In magnetic recording and reproducing devices, the recording signal density is increasing, and in response to this high density recording, so-called metal-coated media and metal-deposited media are being used as magnetic recording media. It has become so.

Since this type of medium has a high coercive force, the magnetic head material used for recording and reproduction is required to have a high saturation magnetic flux density. For example, ferrite materials conventionally used as head materials have a low saturation magnetic flux density.
It cannot cope with the above-mentioned increase in coercive force.

Therefore, in order to support high coercive force magnetic recording media, the magnetic core part is made of a ferromagnetic metal oxide magnetic material such as ferrite, and a ferromagnetic metal thin film is coated on the surface of these magnetic cores facing the magnetic gap. A composite type magnetic head, so-called metal-in-gap type, has been proposed, in which a metal-in-gap type magnetic head is formed and abutted to form a magnetic gap.

As shown in FIG. 3, the magnetic head is formed of a pair of magnetic cores 11 and 12 made of ferromagnetic metal oxide Mn-Zn ferrite, and the opposing surfaces have a magnetic gap g"
The track width is regulated by grooving on both sides. A ferromagnetic metal thin film 13.14 such as Sendust is deposited on the opposing surface of the magnetic core 11.12, and a non-magnetic material 15.16 such as glass is fused and filled on both sides of the magnetic gap g'. .

(1) By the way, the ferromagnetic metal thin film 13.14 is deposited and formed using a vacuum thin film formation technique.The ferromagnetic metal thin film 13.1
4 and the magnetic core 11.12 when heat treated at high temperature, mutual diffusion occurs and a diffusion layer is formed.

That is, when sendust (a ferromagnetic metal thin film) is deposited on ferrite by sputtering and then heat-treated at a high temperature of 450°C to 650°C for glass fusion, Fe atoms in sendust, A/atom,
The S1 atoms diffuse into the ferrite, and the oxygen atoms in the ferrite diffuse into the sendust film. The ferrite portion to which the oxygen atoms have migrated becomes a reduced state, and a crystallographic defect layer is formed. This defective layer is nearly non-magnetic, and since it is located parallel to the main gap g', it has the disadvantage of acting as a pseudo-gap.

The pseudo gap causes a pseudo pulse 32.33 in the solitary wave reproduction waveform as shown in FIG. 5, and the ratio of the signal pulse 31 to the pseudo pulse 32.33 is 15 to -18 dB.
This results in deterioration of the reproduced signal, such as undulations in the frequency characteristics of the reproduced output.

Therefore, an object of the present invention is to prevent the formation of a defect layer at the interface between the magnetic core portion of the ferromagnetic metal oxide and the ferromagnetic metal thin film, and to reduce the influence of the pseudo gap.

1　　　　　　　　,　-.

The magnetic head of the present invention has a ferromagnetic metal thin film deposited on the magnetic gap facing surfaces of a pair of magnetic cores made of ferromagnetic metal oxide, and the metal thin films are butted against each other to form a magnetic gap. A diffusion prevention film made of an oxide of a group 4A metal in the periodic table of elements, such as Ti or Zr, is interposed at least in the vicinity of the magnetic gap at the interface between the ferromagnetic oxide and the ferromagnetic metal thin film. do.

According to the present invention, diffusion of Fe atoms, Si atoms, and AJ atoms from a ferromagnetic metal thin film to a magnetic core at high temperatures is prevented by interposing a diffusion prevention film made of an oxide material such as Ti or Zr. Furthermore, diffusion of oxygen atoms from the magnetic core to the ferromagnetic metal thin film can be reliably prevented.

Fruit” 1 example- Next, the present invention will be explained with reference to the drawings.

FIG. 2 is an external perspective view of the magnetic head of the present invention.
The figure is a partially enlarged view showing the medium sliding movement of the magnetic head.

In this magnetic head, the magnetic cores 1 and 2 are made of a ferromagnetic oxide material, for example, Mn--Zn ferrite, and grooves 5.6 for regulating the track width are formed on both sides.

A winding window 9 is formed in the magnetic core half 1 for supplying or extracting signals to or from the magnetic head.

First, a reaction prevention film 7.8 made of Ti oxide was formed on the inscribed surfaces of the magnetic cores 1 and 2 to a film thickness of 50 to 300 A using a vacuum film technique such as sputtering. Ferromagnetic metal thin films 3 and 4 such as sendust are formed thereon. On top of this, a nonmagnetic oxide thin film such as 5i02 is further formed and then brought together to form a magnetic gap g. The above track width regulation groove has
A non-magnetic material 5,6 such as glass is melted and filled to ensure the mechanical strength of the core.

The anti-diffusion films 7 and 8 made of Ti oxide are heated during the heat treatment when melting and filling the non-magnetic materials 5 and 6.
Mutual diffusion between the ferromagnetic metal thin films 3 and 4 and the ferromagnetic metal materials constituting the magnetic cores 1 and 2 is prevented, and the interface between the magnetic cores 1 and 2 is brought into a low oxygen state, resulting in soft magnetic properties. can be prevented from deteriorating. In addition, the above-mentioned diffusion prevention film 7
, 8, using Ti as a target, using Ar gas as a sputtering gas.
By using the reactive RF sputtering method with the addition of gas, a thermally stable film can be obtained, and the film thickness of the diffusion prevention films 7 and 8 can be made thin, and even a film thickness of 50A can provide sufficient diffusion prevention. The diffusion prevention film itself can be prevented from acting as a pseudo gap.

The conditions for sputtering the Ti oxide mentioned above are as follows: the sputtering gas pressure is 1 m Torr, the ratio of the Ar gas flow rate to the 02 gas flow rate is 4:1, and the input power is 1 m Torr. It is 4.3W per lct/.

For a magnetic head in which magnetic cores 1 and 2 are made of MnZn ferrite, ferromagnetic metal thin films 3 and 4 are made of Fe-8i-AJ alloy, and diffusion prevention films 7 and 8 are made of Ti oxide at 10OA, solitary wave When the playback output was examined, the results were as shown in Figure 4, and the signal output 21
The ratio of 22.23 to the pseudo output due to the pseudo gap was less than -26 dB, which is a level that poses no problem in practice.

In the above embodiment, an oxide of Ti was used as the diffusion prevention film, but in this invention, other oxides such as Zr may also be used. Bye.

As explained above, according to the present invention, by forming a thin oxide film of group 4A metal as a diffusion prevention film between the magnetic core and the ferromagnetic metal thin film, the magnetic core and the ferromagnetic metal thin film are formed. Mutual diffusion of magnetic metal thin films can be prevented, and generation of a magnetically degraded layer in a low oxygen state near the interface of the magnetic core can be suppressed. Further, it is possible to suppress the occurrence of pseudo output in the reproduction output due to the pseudo gap, and to obtain good recording and reproduction.

[Brief explanation of the drawing]

FIG. 1 is an enlarged view of a sliding surface of a medium showing an embodiment of a magnetic head according to the present invention. FIG. 2 is a perspective view of its appearance. 1.2...Magnetic core of ferromagnetic metal oxide, 3.4...
- Ferromagnetic metal thin film, 5.6... Non-magnetic material, 7.8... Ti oxide film, 9... Winding window, g... Magnetic gap. FIG. 3 is an enlarged view of the medium sliding surface of a conventional magnetic head. FIG. 4 is a solitary wave reproduction waveform diagram of the magnetic head according to the present invention. FIG. 5 is a solitary wave reproduction waveform diagram of a conventional magnetic head. 1st Figure 3.4--iju・l'L-艷潟 2nd figure: To ``0 rO 0~ shout + l-1 sweet < state Mku

Claims (1)

[Claims] In a magnetic head comprising a magnetic core made of a ferromagnetic metal oxide constituting a magnetic gap, and a ferromagnetic metal thin film formed on at least one of the opposing surfaces of the magnetic core, the ferromagnetic metal oxide and the ferromagnetic metal oxide are formed at least near the magnetic gap. A magnetic head characterized in that a diffusion prevention film made of an oxide of a metal of group 4A in the periodic table of elements is interposed at an interface with a ferromagnetic metal thin film.