JPS6057512A - Composite type magnetic head - Google Patents

Abstract

PURPOSE:To steepen the component in a vertical direction and to enable high density recording by mating the 1st core formed by depositing an amorphous magnetic material to a high permeability block made into a projecting shape and the 2nd core formed by depositing a polycrystalline magnetic material to a high permeability block so as to face each other via a working gap. CONSTITUTION:An amorphous magnetic alloy 12 such as Co-Zr-Mo is formed to a high permeability block 11 of Mn-Zn ferrite or the like having the projecting section on the surface facing a medium. 13 is a working gap part, 14 is a non- magnetic packing material and 15 is a polycrystalline magnetic alloy such as Fe-Si-Ru. A block 16 has the same shape as the shape of the block 11 and is formed of the same material. The material 12 and the material 15 are both formed of a magnetic material having a satd. magnetic flux density higher than the magnetic flux density of the high permeability blocks 11, 16. The material 15 having a satd. magnetic flux density higher than the satd. magnetic flux density of the material 12 is used. Since the magnetic characteristics of the magnetic cores are asymmetrical, the recording magnetic field intensity in the vertical direction is made strong and steep.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic head for perpendicular magnetic recording, and particularly to a composite magnetic head with excellent recording and reproducing characteristics at high density.

[Background of the invention]

As the coercive force of longitudinal recording media increases, a composite magnetic head formed from a ferrite block coated with a high saturation magnetic flux density magnetic material has been proposed in order to effectively record on the medium. In these composite magnetic heads, the boundary surface of the adhered part functions as a pseudo gap, which tends to cause the so-called contour effect, which causes the frequency characteristics of the reproduced output to wave, and in order to avoid this. Various efforts were made. For example, JP-A-56
Japanese Patent No. 129214 proposes that the magnetic gap component be made of a material having a higher saturation magnetic flux density than the other core parts, and that the material be made to intersect obliquely with the gap part.

However, in the above composite magnetic head, the high saturation magnetic flux density magnetic material coated on the first and second magnetic cores is made of the same material and has approximately the same film thickness, so the recording magnetic field distribution is symmetrical with respect to the gap. However, it is not possible to obtain a sufficiently steep recording magnetic field component in the perpendicular direction, and even if this head is applied as is to a perpendicular magnetic recording device, ideal perpendicular magnetic recording cannot be performed, especially for media with high saturation magnetization. Ta.

[Purpose of the invention]

An object of the present invention is to provide a composite magnetic head for perpendicular magnetic recording in which the component of the recording magnetic field in the direction perpendicular to the medium is steep and capable of high-density recording.

[Summary of the invention]

We believe that it is effective to make the magnetic core structure magnetically asymmetric in order to steepen the recording magnetic field component in the direction perpendicular to the medium. As a result of actually fabricating prototype composite film heads with various characteristics and structures and evaluating the characteristics, we found that at least both sides of the protrusions of a high magnetic permeability ferrite block having protrusions with a protruding cross-sectional shape on the surface facing the magnetic recording medium. A first magnetic core having a surface coated with an amorphous magnetic film having a higher saturation magnetic flux density than the ferrite, and a polycrystalline magnetic material having a higher saturation magnetic flux density than the ferrite at least near the working gap have high magnetic permeability. A composite magnetic head formed with a second magnetic core deposited on a ferrite block facing each other across an operating gap at the tip of the protrusion has excellent recording and reproducing characteristics, especially at high density. It became clear that there was. Further, it is preferable that the second core also has a protrusion with a protruding cross-sectional shape on the surface facing the magnetic recording medium, so that the contour effect is further reduced. Particularly good recording density characteristics were obtained when the saturation magnetic flux density was higher than that of the amorphous magnetic layer material.

[Embodiments of the invention]

An embodiment of the present invention will be explained below with reference to FIG. The same figures (a) and (b) respectively show a perspective view and a plan view, and 11 is Mn-Zn ferrite, N1-Znyn
Ferrite high permeability block, 12 is well-known Co-Z
r-Mo, Co-Z r-Nb, Co-Zr-
Amorphous' such as W, Co-Nj-Zr! A magnetic alloy or a laminate of these and an insulating layer such as S i 02 or AlaOs, 13 is an operating gap formed of S j 02 or At203, 14 is a non-magnetic filler such as glass adhesive, 15 is a Well-known Fe-5i-au+pe
-s 1-ht* Fe-Ti, Ni-Fe, so polycrystalline magnetic alloy, or 5iOz with them.

A laminate with an insulating layer such as A2t3, 16 is M n -Z
It is a high magnetic permeability block such as n-ferrite or Ni-Zn ferrite.

Other embodiments are shown in FIGS. 2, 3, and 4, respectively. 2
1-26.31-36.41-46 are 11-1 respectively
6, and in FIG. 2, 25 may or may not reach the bottom of 26.

According to the present invention, since the magnetic properties of the magnetic core are asymmetrical, the recording magnetic field strength in the perpendicular direction is strong and steep, so that the saturation magnetization is, for example, 500 emu/cc.

Film thickness Q, 25 μm, coercive force 5000e (D Co −
Using a two-layer perpendicular medium in which a Cr thin film was beaten with a 0.9 μm CoZr-Mo magnetic film, the relative speed was 1.25 m/cm.
When the characteristics were evaluated using S, particularly excellent recording characteristics were obtained as shown in FIG. Here, 51 is the characteristic of the head having the structure shown in FIG. 1, 11°16 is MnZn ferrite with a saturation magnetic flux density of 0.52 T, and 12 is Co-Zr with a saturation magnetic flux density of 0.9 T and a film thickness of 5 μm. -Nb to O, 1μ
The amorphous magnetic layers were each laminated with four S102 layers of m, and the gap 13 was formed of Sio2, and the gap length was 0.15 μm.

14 is filled glass, and 15 is a saturation magnetic flux density of 0.9T.

0.04 μm (7) S of Nr-pe-Mo with a film thickness of 1 μm
These are polycrystalline magnetic layers each having 155 laminated layers with i02 layers in between, and θ1 is about 60° and θ2 is about 90°. 52 is the characteristic of the head having the structure shown in FIG. 2, and 21.26 is N+Zn ferrite, 2
2 with a saturation magnetic flux density of 1.1 T and a film thickness of 6 pm.
r - M o k O, non-quality magnetic layers each laminated with 6 layers through Akos layers of 08 μm, gap 23 is 5
24 is filled glass, 25 is a saturation magnetic flux density of 1.0 T, and 8 layers of Ni-Fe with a film thickness of 1.5 μm are laminated via S'02 of 0.06 μm. It is a polycrystalline magnetic layer and θ3 is approximately 50°
That is. 53 is the characteristic of the head having the structure shown in FIG. 4, 41.46 is M n -Z n 7 x light core, 42 is saturation magnetic flux density 11.4 T, film thickness 20 μm
co-zr-w single layer film, 43 is a gap with a gap length of 0.25 μm made of A120h, 44 is filled glass,
45 is p with a saturation magnetic flux band ff1.5T and a film thickness of 0.2 μm.
e-'J'i with 0.05 μm A1. 50 layers were each formed through z03. In the same figure, the structure shown in Fig. 4 is shown, and both 42.45 and 20 μm Co-zr
The characteristics when the head is formed using -w are shown in 54, and it can be seen that the head having the structure according to the present invention has particularly excellent characteristics at high density.

In FIG. 6, a Co--Cr thin film with a saturation magnetization of 350 emu/cc, a film thickness of 0.2 μm, and a coercive cuff of 000e is deposited using a composite head having the structure shown in FIG. , 5 pm Co-z r-w magnetic film lined with a two-layer film medium at a relative speed of 2.5 m/s.

61 is in Fig. 3, 31.36 is Mn-7,n ferrite, and 32 is Co-Zr with saturation magnetization of 13.5T and film thickness of 7 μm.
-B is a 5-layer laminated film with a 0.1 pm SiO□ layer interposed therebetween, 33 is 0.2 μm 5jOz, 34 is filled glass, 35 is saturation magnetization 1.9T1 film thickness 0.1 pm
of Fe-5i-Ru with a film thickness of 0.005 pm (D N
It is the characteristic of a composite head made of polycrystalline magnetic films laminated with 500 layers of i-p 6 and 62, where 35 parts are IT with saturation magnetization, Ni-Fe with a film thickness of 0.2 μm, and Ni-Fe with a film thickness of 0.
．． Although the properties of the composite head changed from polycrystalline magnetic films each made of 311 layers of 07 μm 8i02 were obtained, excellent characteristics were obtained in both cases, but in particular, the saturation magnetic flux density of the 35 parts of the polycrystalline magnetic material was It can be seen that the higher the saturation magnetic flux density of the amorphous magnetic material portion 32, the better the characteristics.

The embodiments related to so-called narrow-gap ring-type heads have been described above, but this effect can be obtained even in the structure shown in FIG. 7, in which the gap length and the film thickness of the high saturation magnetic flux density material are significantly changed. Properties comparable to those shown were obtained. Here, 71.76 is M n -Z n ferrite, 72 is a Co-zr-w amorphous magnetic film with a film thickness of 2 (14 m), 73° 73' is a 5i02 gap length with a thickness of 2 μm each, and 74 is a filled Glass, 75 has a saturation magnetization of 1.8 T, a film thickness of 0.05 μm] Ii” e-81-Ru and a film thickness of 0.0
05 μm (DC.

This is a polycrystalline magnetic film in which four layers are laminated.

〔Effect of the invention〕

As described above, the composite magnetic head according to the present invention not only has excellent recording and reproducing characteristics, but also has a sufficiently small contour effect, and is excellent for perpendicular magnetic recording, especially in high-density recording and reproducing characteristics. is excellent.

[Brief explanation of the drawing]

Figures 1 (a), (b), Figures 2 (Ca), (b), Figures 3 and 4 are perspective views of the composite head in each embodiment of the present invention or the operation of the surface facing the recording medium. A plan view of the vicinity of the gap, FIGS. 5 and 6 are graphs showing the characteristics of the head, and FIG. 7 is a perspective view of a composite head according to another embodiment. 11.16,21,26,31,36,71°76...
・Ferrite block, 12, 22, 32° 42.72
...Thin film made of amorphous magnetic material, 15°25.35,
45.75 Thin film made of polycrystalline magnetic material, 14.
24,34,44.74...Nonmagnetic filler, 13,2
3, 33, 43, 73. 73'... Cast part, 51,
52.53, 61.62 Characteristics of the composite head according to the present invention, 54 Characteristics of the conventional head. (Delivery) 3rd flash (shi) 2 mouth 4th mouth 5th kryl 6 Figure this 銖'jlL D (kryl) Continuation of day 7, page 1 ■Inventor Kosei Shinagawa 1-28 Higashikoigakubo, Kokubunji City Location: Hitachi, Ltd. Central Research Laboratory

Claims (1)

[Scope of Claims] 1. A high magnetic permeability ferrite block having a protrusion with a protruding cross-sectional shape on the surface facing the magnetic recording medium has an amorphous material having a higher saturation magnetic flux density than the ferrite on at least both sides of the protrusion. a first magnetic core coated with a magnetic material;
A second magnetic core in which a polycrystalline magnetic material having a saturation magnetic flux density higher than that of the ferrite is deposited on a high magnetic permeability ferrite block at least near the working gap is connected to the second magnetic core through the working gap at the tip of the protrusion. A composite magnetic head characterized by facing each other. 2. The composite magnetic head according to claim 1, wherein the second magnetic core also has a protrusion with a protruding cross-sectional shape on the surface facing the magnetic recording medium. 3. The polycrystalline magnetic material has a higher saturation magnetic flux density than the amorphous magnetic material.