JPH08115505A - Magnetic head - Google Patents

Abstract

PURPOSE: To improve the wear resistance of substrate on a medium-sliding surface by composing at least a part of the substrate of a CaTiO3 -ZrO2 -based oxide contg. a ZrO2 -based oxide at a specific ratio. CONSTITUTION: This laminated magnetic head is composed by butting a pair of magnetic core half bodies 1, 2 constituting a closed magnetic path against each other, joining and integrating these core half bodies and forming a magnetic gap G facing the magnetic recording medium-facing surface 3 between these butt surfaces 1a and 2a. The half bodies 1 are formed by sandwiching a laminated magnetic material film 4 which is metallic magnetic film, in the film thickness direction with a pair of the substrates 11, 11b which are nonmagnetic. The substrates 11, 12 constituting the magnetic core half bodies 1, 2 of such magnetic head are composed of the CaTiO3 -ZrO2 -based oxide contg. the ZrO2 -based oxide at the ratio of 20 to 80vol.%.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a magnetic recording / reproducing apparatus such as a video tape recorder (hereinafter referred to as VTR), a digital audio tape recorder (hereinafter referred to as DAT), or a digital data recording apparatus. The present invention relates to a magnetic head used for high-density recording of an audio signal, a video signal, an information signal, or the like as a magnetic signal on a recording track of a magnetic recording medium such as a magnetic tape.

[0002]

2. Description of the Related Art Conventionally, a magnetic recording / reproducing apparatus such as a VTR or DAT which uses a magnetic tape or the like as a magnetic recording medium reads an information signal recorded on the magnetic tape or records on the magnetic tape. Records and /
Alternatively, a magnetic head for reproduction is provided.

In recent years, in order to record or reproduce a larger number of information signals for the purpose of improving the image quality of recording or reproducing video signals or for increasing the storage capacity, a signal having a shorter wavelength is used. The method of recording or reproducing is adopted. For this reason, a ferromagnetic metal powder is used as the magnetic powder used in the magnetic layer, and a high coercive force such as a metal tape obtained by coating this on the base film or a vapor deposition tape obtained by directly depositing a ferromagnetic metal material on the base film. Magnetic recording media are used.

In order to enable recording or reproduction on these high coercive force magnetic recording media, a metal magnetic material having a high magnetic permeability and a high saturation magnetic flux density, such as an iron alloy, is used as a magnetic core material. So-called laminated magnetic heads, MIG magnetic heads, and the like using iron-nickel alloys, iron-cobalt alloys, and the like have been proposed.

In the laminated magnetic head described above, a pair of magnetic core halves are formed by sandwiching a metal magnetic film between a pair of substrates made of a non-magnetic material in the film thickness direction. It is a magnetic head configured by joining and integrating by wearing or the like.

[0006]

In the above laminated magnetic head, the thermal expansion coefficient of the substrate is close to the thermal expansion coefficient of the metal magnetic film, and the substrate is suitable for various high coercive force magnetic recording media. It is required to have excellent wear resistance and the like.

In the above laminated magnetic head, when the coefficient of thermal expansion of the substrate is significantly different from that of the metal magnetic film,
There is a problem that the metal magnetic film formed on the substrate is peeled off or the substrate is cracked. Further, there arises a problem that the excellent magnetic characteristics of the metal magnetic film cannot be sufficiently brought out, and the head efficiency is lowered. Therefore, it is said that the substrate preferably has a coefficient of thermal expansion of 100 × 10 ⁻⁷ / ° C. or more.

Further, in the above laminated magnetic head,
If the amount of abrasion of the magnetic tape of the substrate against the high coercive force magnetic recording medium is large, the life of the medium is shortened.

Therefore, the present invention has been proposed in view of the conventional circumstances, and a magnetic head in which the coefficient of thermal expansion and wear resistance of the substrate are controlled, the head efficiency is high, and the life as a magnetic head is sufficient is provided. The purpose is to propose.

[0010]

In order to achieve the above-mentioned object, the present invention provides a pair of magnetic core halves formed by sandwiching a metal magnetic film between a pair of substrates in the thickness direction of the metal magnetic film. In a magnetic head in which end faces face each other and are joined and integrated so that a magnetic gap is formed between the butted faces, at least a part of the substrate has a ZrO ₂ -based oxide content of 20 to 80% by volume. It is characterized by comprising the CaTiO ₃ —ZrO ₂ based oxide contained in 1.

[0011] At this time, when the ratio of the CaTiO ₃ -ZrO ₂ system ZrO ₂ based oxides in the oxide is less than 20 volume%, giving sufficient wear resistance to the CaTiO ₃ -ZrO ₂ based oxide Cannot be achieved, and the wear resistance of the magnetic head becomes insufficient. On the other hand, the proportion of ZrO ₂ -based oxide is 8
If it is more than 0% by volume, the coefficient of thermal expansion of the CaTiO ₃ —ZrO ₂ based oxide becomes too small, leading to a reduction in the head efficiency of the magnetic head.

Further, in the magnetic head of the present invention, at least a part of the sliding surface of the substrate with respect to the magnetic recording medium is Zr.
Ca containing 20 to 80% by volume of O ₂ -based oxide
It is preferably made of a TiO ₃ —ZrO ₂ based oxide.

Further, in the magnetic head of the present invention,
At least one kind of Y ₂ O ₃ and CeO ₂ is contained in the ZrO ₂ -based oxide in the CaTiO ₃ —ZrO ₂ -based oxide at a ratio of 55 mol% or less, or Ca
It is preferable that at least one of O and MgO is contained at a ratio of 30 mol% or less.

At this time, at least one of Y ₂ O ₃ and CeO ₂ is contained in an amount of more than 55 mol%,
Alternatively, when at least one of CaO and MgO is contained in an amount of more than 30 mol%, CaTiO ₃ —Zr
This is not preferable because the strength of the O ₂ type oxide is deteriorated.

In order to further improve the head efficiency of the magnetic head of the present invention, the metal magnetic film is a laminated magnetic film formed by laminating a plurality of unit laminated magnetic films with an insulator film interposed therebetween, and the unit laminated structure is formed. It is preferable that a plurality of magnetic material films are laminated via a non-magnetic material film, and the laminated magnetic material films are magnetostatically coupled to each other at their ends.

The inventors of the present invention have previously proposed Japanese Patent Application No. 6-1
As disclosed in Japanese Patent No. 6047, in a laminated magnetic head as described above, a laminated magnetic film in which a plurality of unit magnetic layers forming a magnetic core half body are laminated with an insulating film interposed therebetween. If the unit laminated magnetic film is formed by laminating a plurality of magnetic films through a non-magnetic film, and the laminated magnetic films are magnetostatically coupled to each other at the ends. It is proposed that the head efficiency can be improved, especially in a high frequency region.

At this time, the magnetic film contains Co as a main component, and Zr, Mo, Nb, Ta, Ti, Hf, and P are used.
It is preferable to contain at least one element selected from d.

[0018]

In the magnetic head of the present invention, at least a part of the substrate sandwiching the metal magnetic film from the film thickness direction is made of ZrO 2.
CaT containing ₂ to 80% by volume oxide
Since it is composed of an iO ₃ -ZrO ₂ -based oxide, the coefficient of thermal expansion of the substrate is close to the coefficient of thermal expansion of the metal magnetic film, and the head efficiency is good.

In the magnetic head of the present invention, at least a part of the sliding surface of the substrate on the magnetic recording medium is ZrO 2.
CaT containing ₂ to 80% by volume oxide
With the iO ₃ -ZrO ₂ -based oxide, the wear resistance of the substrate on the sliding surface of the medium is good, so that the product life of the magnetic head is extended.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described in detail below with reference to the drawings.

The magnetic head of this embodiment is a laminated magnetic head, and as shown in FIG. 1, a pair of magnetic core halves 1 and 2 forming a closed magnetic path are butted and joined together to form a magnetic head.
A magnetic recording medium sliding surface 3 is provided between the abutting surfaces 1a and 2a.
The magnetic gap G facing the above is formed.

The magnetic core half body 1 has a pair of substrates 11a, 11 having a non-magnetic laminated magnetic film 4 which is a metal magnetic film.
The magnetic core half body 2 is sandwiched between the pair of substrates 12a and 12b, which are nonmagnetic, in the magnetic core half body 2, and the magnetic core half body 2 is sandwiched between the pair of substrates 12a and 12b. .

Then, the end faces 4a, 5a of the laminated magnetic film 4, 5 between the abutting faces 1a, 2a of the magnetic core halves 1, 2.
A magnetic gap G is formed between them.

The track width of the magnetic gap G indicated by Tw in the figure is restricted by the film thickness of the laminated magnetic films 4, 5 since the substrates 11, 12 are non-magnetic.

A winding window 6 is formed on the side of the abutting surface 1a of the magnetic core half 1 for regulating the depth of the magnetic gap G indicated by Dp in the drawing and winding a coil (not shown). .

In the magnetic head of this embodiment, the substrates 11 and 12 forming the magnetic core halves 1 and 2 are
It is constituted by CaTiO ₃ -ZrO ₂ system oxide containing ZrO ₂ based oxide in a proportion of 20 to 80 volume%.

Further, in the magnetic head of this embodiment,
For the purpose of improving the head efficiency of the laminated magnetic films 4 and 5, as shown in FIG. 2 (only the laminated magnetic film 4 is shown in FIG. 2, but the laminated magnetic film 5 is also the same. ),
The unit laminated magnetic film 33 is formed by laminating a plurality of unit laminated magnetic films 33 with an insulator film 34 interposed therebetween.
3, a plurality of magnetic material films 31 are laminated via a non-magnetic material film 32, and the laminated magnetic material films 31 are magnetostatically coupled at their ends.

Subsequently, ZrO ₂ in the CaTiO ₃ --ZrO ₂ system oxide forming the substrate of the magnetic head of the above-mentioned embodiment is used.
The relationship between the content of the system oxide, the coefficient of thermal expansion of the CaTiO ₃ —ZrO ₂ system oxide, and the wear resistance of the magnetic head was investigated.

That is, CaTiO ₃ --ZrO ₂ containing a ZrO ₂ type oxide containing Y ₂ O ₃ at a ratio of 8 mol%.
The content of the ZrO ₂ type oxide in the type oxide is ₂₀ to 8
A substrate with the content changed to 0% by volume was prepared, and the magnetic head of this example having the above structure was manufactured by using the substrate, and the thermal expansion coefficient of the substrate and the wear resistance of the magnetic head were investigated.

For comparison, Y ₂ O ₃ was added in an amount of 8 mol%.
CaTiO ₃ containing ZrO ₂ -based oxide
The content of -ZrO ₂ based oxide the ZrO ₂ based oxide in preparing the substrate was changed up to 0-20% by volume, or 80 to 100% by volume, of the present embodiment having the above structure with reference to this A magnetic head similar to the magnetic head was manufactured, and the coefficient of thermal expansion of the substrate and the wear resistance of the magnetic head were investigated.

In the above magnetic head, 2 mm
(Width) × 2 mm (height) × 0.2 mm (thickness), the track width is 19.6 μm, the contact width is 70 μm,
The sliding surface of the magnetic recording medium was a curved surface with a radius of curvature of 8 mm.

In the above magnetic head, the laminated magnetic films 4 and 5 are formed by laminating nine unit laminated magnetic films 33 with the total thickness of 19.6 μm with the insulating film 34 interposed therebetween. The body film 33, the magnetic body film 31, and the non-magnetic body film 3
It was assumed that 8 layers were laminated with 2 in between. The magnetic film 31 is a Co-Zr-Nb-Ta amorphous film having a film thickness of 241 nm, and the non-magnetic film 32 is a Si film having a film thickness of 10 nm.
And O ₂ film, an insulator film 34 of SiO with a thickness of 200 nm ₂
It was a film.

The magnetic film 31 is formed by a DC magnetron sputtering apparatus using a target having a composition of Co ₈₁ Zr ₄ Nb ₁₂ Ta ₃ (subscripts represent atomic%) and a power density of 5.0 W / cm ² . The film was formed with an argon gas pressure of 0.4 Pa and an interelectrode distance of 100 mm.

Further, the SiO ₂ films of the non-magnetic film 32 and the insulating film 34 are formed by a high frequency sputtering device with a power density of 1.0 W / cm ² , an argon gas pressure of 0.4 Pa and an electrode distance of 100 mm. A film was formed.

The wear resistance of the above magnetic head was investigated as follows. That is, the protrusion of each magnetic head from the drum is set to 30 μm, and the magnetic head is mounted on a Sony VTR (trade name: BVW-50). On the other hand, a Sony video tape (trade name: BCT-90ML and BC) is used.
T-90MLA, hereinafter referred to as Tape A and Tape B, respectively. 100) under the conditions of 30 ° C. and 80% (RH).
After traveling for a time, the amount of wear of the magnetic head (change in protrusion) at this time was investigated.

Table 1 shows the content of the ZrO ₂ type oxide in the substrate, the tape A and the tape B of the magnetic head using the substrate.
The amount of wear, the coefficient of thermal expansion α of the substrate, and the comprehensive evaluation determined from these results are also shown.

[0037]

[Table 1]

As described above, in the multi-layer magnetic head, the wear resistance is better as the wear amount on the tape is large and the head life is shortened, and the thermal expansion coefficient of the substrate is the same as that of the metal magnetic film. 100 ° C x 10 in consideration of balance
^-7 / ° C or higher is desirable.

Therefore, from the results of Table 1, when the content of the ZrO ₂ -based oxide in the CaTiO ₃ -ZrO ₂ -based oxide constituting the substrate is 20 to 80% by volume, the wear amount and the thermal expansion coefficient are set. It was confirmed that a well-balanced and good result was obtained.

As described above, in the magnetic head in which the substrate is made of CaTiO ₃ --ZrO ₂ -based oxide containing 20 to 80% by volume of ZrO ₂ -based oxide as in the magnetic head of this embodiment. The coefficient of thermal expansion of the substrate is close to the coefficient of thermal expansion of the metal magnetic film, and the head efficiency is good. Further, in the magnetic head of this embodiment, the medium sliding surface is also made of the CaTiO ₃ --ZrO ₂ -based oxide, so that the wear resistance is good and the product life of the magnetic head is long.

In the above examples, the ZrO ₂ type oxide containing 8 mol% of Y ₂ O ₃ was used, but in addition to this, at least one of Y ₂ O ₃ and CeO ₂ is used. Z containing 55 mol% or less, or at least one of CaO and MgO in a ratio of 30 mol% or less
The same effect was obtained by using the rO ₂ -based oxide.

In the above embodiment, the magnetic film 3 is used.
1 was composed of a Co—Zr—Nb—Ta amorphous film having a composition of Co ₈₁ Zr ₄ Nb ₁₂ Ta ₃ (subscript indicates atomic%).
The film that has been formed as the film that constitutes Co _a Zr _b N
b _c Ta _d [where subscripts a, b, c, and d represent the proportion (atomic%) of each element. ] The composition range is 79 ≦ a ≦ 83, 2 ≦ b ≦ 6, 10 ≦ c ≦ 1
Even if 4,1 ≦ d ≦ 5 is used, the same effect as that of the above-described embodiment can be obtained.

Further, in the above embodiment, the substrate 1
1,12 is has been described consisting example by CaTiO ₃ -ZrO ₂ system oxide containing ZrO ₂ based oxide in a proportion of 20 to 80 volume%, the CaTiO ₃ substrate
It may be constituted by a bonding material between -ZrO ₂ based oxide and the magnetic ferrites.

A magnetic head using the above bonding material is
An example is shown in FIG. That is, the magnetic core half body 41 and the laminated magnetic film 45, which have substantially the same structure as the magnetic head shown in FIG. 1 and in which the laminated magnetic film 44 is sandwiched between the pair of substrates 51a and 51b, form a pair. The magnetic core half 42 sandwiched between the substrates 52a and 52b is joined and integrated by forming a magnetic gap G facing the medium sliding surface 43 between the abutting surfaces.

The medium sliding surface side portion 46 of the substrate 51a is made of the above CaTiO ₃ --ZrO ₂ system oxide, the remaining back gap side portion 47 is made of magnetic ferrite, and the other substrate 51b, 52a, 52
Examples of b have the same configuration. Also in such a magnetic head, the head efficiency is improved and the product life is extended, as in the magnetic head described above.

Further, as shown in FIG. 5, the present invention has substantially the same structure as the magnetic head shown in FIG. 1, and the laminated magnetic film 64 is sandwiched between the pair of substrates 71a and 71b. The magnetic core half body 61 and the laminated magnetic film 65 are sandwiched by the pair of substrates 72a and 72b, and the magnetic core half body 62 is joined between the abutting surfaces to form a magnetic gap G facing the medium sliding surface 63. The magnetic heads are integrated and can be applied to a magnetic head in which the laminated magnetic films 64 and 65 are obliquely crossed with respect to the magnetic gap G and are linearly connected.

In the above-mentioned embodiments, the Co--Zr--Nb--Ta amorphous film is used as the magnetic material film in the laminated magnetic material film, but in addition to this, it has a high saturation magnetic flux density,
Any ferromagnetic alloy material film having excellent soft magnetic properties can be used. As the ferromagnetic alloy material, any conventionally known material can be used, and it may be crystalline or amorphous.

For example, Fe-Al-Si alloy, Fe-Si-Co alloy, Fe-Ni alloy, Fe
-Al-Ge-based alloy, Fe-Ga-Ge-based alloy, Fe-
Si-Ge based alloy, Fe-Si-Ga based alloy, Fe-S
Examples thereof include i-Ga-Ru alloys and Fe-Co-Si-Al alloys. Furthermore, in order to further improve the corrosion resistance and wear resistance, the above alloys may be added with Ti, Cr, Mn,
Zr, Nb, Mo, Ta, W, Ru, Os, Rh, I
At least one metal such as r, Re, Ni, Pd, Pt, Hf, and V may be added.

A ferromagnetic amorphous metal alloy, a so-called amorphous alloy (for example, an alloy composed of one or more elements of Fe, Ni, Co and one or more elements of P, C, B, Si, or With these as the main components, Al, Ge, Be,
Sn, In, Mo, W, Ti, Mn, Cr, Zr, H
Metal-metalloid type amorphous alloys such as alloys containing f, Nb, etc., or metal-metal type amorphous alloys containing transition elements such as Co, Hf, Zr etc., rare earth elements, etc. as the main components).

Further, in the above-mentioned embodiments, the laminated magnetic film is formed by the DC magnet sputtering device and the high frequency sputtering device, but the sputtering method by another device excellent in the film thickness controllability or the vacuum deposition. Law,
The film may be formed by a vacuum thin film forming technique typified by an ion plating method and an ion beam method.

[0051]

As is apparent from the above description, according to the present invention, a pair of magnetic core halves formed by sandwiching a metal magnetic film between a pair of substrates in the film thickness direction are provided so that end faces of the metal magnetic film are In a magnetic head formed by butting and joining so as to face each other and forming a magnetic gap between the butting surfaces, at least a part of the substrate is
Since it is made of CaTiO ₃ —ZrO ₂ -based oxide containing a ZrO ₂ -based oxide in a proportion of 20 to 80% by volume, the thermal expansion coefficient of the substrate is close to the thermal expansion coefficient of the metal magnetic film, and the head The efficiency is good.

In the magnetic head of the present invention, at least a part of the sliding surface of the substrate with respect to the magnetic recording medium is made of ZrO 2.
CaT containing ₂ to 80% by volume oxide
With the iO ₃ -ZrO ₂ -based oxide, the wear resistance of the substrate on the sliding surface of the medium is good, so that the product life of the magnetic head is extended.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a magnetic head to which the present invention is applied.

FIG. 2 is a plan view schematically showing a laminated magnetic film of an example of a magnetic head to which the present invention is applied.

FIG. 3 is a perspective view showing another example of a magnetic head to which the present invention is applied.

FIG. 4 is a perspective view showing still another example of a magnetic head to which the present invention is applied.

[Explanation of symbols]

 1, 2, 41, 42, 61, 62 Magnetic core halves 1a, 2a Butting surface 3, 43, 63 Medium sliding surface 4, 5, 44, 45, 64, 65 Laminated magnetic film 4a, 5a End surface 11, 12, 51, 52, 71, 72 Substrate 31 Magnetic film 32 Non-magnetic film 33 Unit laminated magnetic film 34 Insulator film 46 Medium sliding surface side part 47 Back gap side part G Magnetic gap

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Akira Urai 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (5)

[Claims] 1. A pair of magnetic core halves sandwiching a metal magnetic film between a pair of substrates in the film thickness direction are butted and joined together so that the end faces of the metal magnetic film face each other, and the butted surfaces are joined together. In a magnetic head having a magnetic gap formed between them, at least a part of the substrate is made of a ZrO ₂ -based oxide.
CaTiO ₃ —ZrO ₂ contained in a proportion of ˜80% by volume
A magnetic head characterized by comprising a system oxide. 2. A substrate, at least a part of a sliding surface of which is in contact with a magnetic recording medium, is made of CaTiO ₃ --ZrO ₂ -based oxide containing 20 to 80% by volume of ZrO ₂ -based oxide. The magnetic head according to claim 1. 3. Z in a CaTiO ₃ —ZrO ₂ -based oxide
In the rO ₂ -based oxide, at least one of Y ₂ O ₃ and CeO ₂ is contained in a proportion of 55 mol% or less.
Alternatively, at least one of CaO and MgO is contained at a ratio of 30 mol% or less, and the magnetic head according to claim 1 or 2. 4. The metal magnetic film is a laminated magnetic film in which a plurality of unit laminated magnetic films are laminated with an insulator film interposed therebetween, and the unit laminated magnetic film comprises a magnetic film with a non-magnetic film interposed therebetween. 2. The magnetic head according to claim 1, wherein a plurality of the magnetic films are laminated, and the laminated magnetic films are magnetostatically coupled to each other at their ends. 5. The magnetic film mainly contains Co, and Zr, M
5. At least one element selected from o, Nb, Ta, Ti, Hf, and Pd is contained.
The magnetic head described.