JPS6236702A - Magnetic recording method - Google Patents

Abstract

PURPOSE:To obtain large reproduced output at a short wavelength by bringing a thin magnetic film provided to one side of a gap part to a leading edge side and inclining the columnar crystal particles of a thin film type magnetic recording medium in the direction opposite to the moving direction of the thin film type magnetic recording medium and making recording in the thin film type magnetic recording medium. CONSTITUTION:A substrate 2 consists of a high-polymer material and a Co-Cr alloy film is excellent as a magnetic layer 3 in terms of saturation magnetization, coercive force and corrosion resistance. A ring type magnetic head is basically constituted in such a manner that a pair of wiring magnetic materials 4 and 4' constituting a head core face each other with a nonmagnetic layer 6 as a gap material in-between. However, the ring type magnetic head H to be used is formed with the thin magnetic film 5 having the saturation magnetization larger than the saturation magnetization of the wiring magnetic material 4 and the magnetic material 4' between the material 4' and the layer 6 and recording is made by passing signal current to the wiring 7. The columnar crystal particles of the magnetic layer 3 of the thin film type magnetic recording medium 1 are inclined by theta in average with the perpendicular 9 of the film plane.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording method that provides a large short wavelength reproduction output.

BACKGROUND OF THE INVENTION Perpendicular magnetic recording is attracting attention as a magnetic recording system with inferior short wavelength recording characteristics. This method requires a magnetic layer having perpendicular magnetic anisotropy. When a signal is recorded in such a magnetic layer, the residual magnetization is oriented in a direction substantially perpendicular to the film surface. Therefore, as the wavelength of the signal becomes shorter, the demagnetizing field within the medium decreases, and a larger reproduction output can be obtained. Perpendicular magnetic recording media have magnetic layers on a substrate, such as 0o-Or, Co-V, Co
A perpendicular magnetic anisotropic film such as -Ru or Co-Or-Rh is formed by sputtering or vacuum evaporation.

As a magnetic head for recording signals on a perpendicular magnetic recording medium, a ring-type magnetic head that has been in practical use or a known single-pole perpendicular magnetic head has been considered. Ring-type magnetic heads have a weak perpendicular magnetic field component, making it difficult to record signals on perpendicular magnetic recording media, whereas single-pole perpendicular magnetic heads have a magnetic field that is optimal for magnetizing perpendicular magnetic recording media. occurs, and excellent recording characteristics can be obtained.

Problems to be Solved by the Invention As mentioned above, if a single-pole perpendicular magnetic head is used, near-ideal recording can be performed on a perpendicular magnetic recording medium, but this single-pole perpendicular magnetic head generally has poor reproduction efficiency. There is a problem in that the playback output is quite small because of the low output. Furthermore, when a ring-type magnetic head is used, although the reproduction efficiency is high, satisfactory recording on a perpendicular magnetic recording medium is difficult, and the reproduction output is low, which is still insufficient for practical use.

Means for Solving the Problems The present invention provides a ring-shaped magnetic head in which a pair of magnetic bodies are opposed to each other via a magnetic thin film and a nonmagnetic layer having a higher saturation magnetization than the magnetic bodies to form a gap portion, and A thin-film magnetic recording medium composed of columnar crystal grains tilted with respect to the substrate surface is brought into contact with the magnetic layer deposited on one surface of the substrate, and the ring-shaped magnetic head and the thin-film magnetic recording medium are placed in contact with each other at the magnetic layer. The moving direction is moved so that the magnetic thin film of the ring-shaped magnetic head is on the leading edge side, and the recording is performed so that the inclination direction of the columnar crystal grains of the thin-film magnetic recording medium is substantially opposite to the moving direction.

The ring-type magnetic head used in the present invention, in which a magnetic thin film with a large action saturation magnetization is formed on one side of the gap, generates a stronger magnetic field in the vicinity of this magnetic thin film than a conventional ring-type magnetic head. In a region where this strong magnetic field exists, when a signal is recorded on a thin film magnetic recording medium in which the columnar crystal grains are inclined with respect to the perpendicular to the film surface, the inclination of the columnar crystal grains and the ring-shaped magnetic head of the present invention occur. Since the directions of the magnetic fields are close, more sufficient recording is possible than with a conventional combination of a ring-type magnetic head and a perpendicular magnetic recording medium. Furthermore, the direction of relative movement between the medium and the head is adjusted so that the magnetic thin film on the gap surface of the ring-shaped magnetic head is on the leading edge side.
Furthermore, when the columnar crystal grains of the medium are tilted in a direction substantially opposite to the direction of movement of the medium relative to the head, recording demagnetization is reduced.

The above effects improve the recording efficiency, and as a result, the reproduction output increases.

fruit! Example M Figure 1 is a schematic diagram of recording signals on a thin film type magnetic recording medium in which tilted columnar crystal grains are deposited using the ring-type magnetic layer of the present invention, and Figure 2 is a diagram of the thin film type used in the present invention. A structural diagram of a magnetic recording medium is shown.

In the figure, (1) is a thin-film magnetic recording medium, (2) is a substrate, (3) is a magnetic layer, H is a ring-shaped magnetic head of the present invention, (4) is a wire-wound magnetic material, and (4)' is a A magnetic substance, (5) a magnetic thin film, (6) a nonmagnetic layer, (7) a winding wire, and α [a columnar crystal grain body].

The present invention is a magnetic recording method for recording signals on a medium fil in which a magnetic layer (3) has a columnar structure using a ring-type magnetic head H. The substrate (2) is made of a polymeric material, etc., and as the magnetic layer (3), a 00 alloy film is excellent, and a Co--Or alloy film is particularly preferred in terms of saturation magnetization, coercive force, corrosion resistance, etc. Furthermore, a nonmagnetic layer such as T1, I'J3203, Go, etc. may be provided between the substrate (2) and the magnetic layer (3). The ring-type magnetic head of the present invention has a basic configuration similar to a general ring-type magnetic head, including a pair of wire-wound magnetic bodies (4) and a magnetic body 4 constituting the head core.
)' are opposed to each other with a nonmagnetic layer (6) serving as a gap material in between. However, the ring-shaped magnetic head H used in the present invention has a wire-wound magnetic material (4), a magnetic thin film (with a larger saturation magnetization than the magnetic material (4Y)) between the magnetic material (4Y) and the non-magnetic layer (6). 5) is formed.The winding (7
) for recording by passing a signal current through it.

The arrow (8) in FIG. 1 indicates the direction of relative movement of the thin film type magnetic recording medium (1) with respect to the ring type magnetic head H. In the ring type magnetic head H, a thin film type magnetic recording medium (1
The area near the gap of the herad core on the side where 1 enters is called the leading edge, and the opposite side is called the trailing edge. When the ring-shaped magnetic head H and the thin-film magnetic recording medium +11 move relative to each other in the direction of the arrow (8) as shown in FIG. When the moving direction is opposite to the arrow (8), the magnetic thin film (5) is on the trailing edge side. The magnetic layer (
The columnar crystal grains in 3) are tilted by an average of θ with respect to the perpendicular to the film surface (9), and the direction opposite to the movement direction means 0°.
θ<90°'f means gold.

FIG. 2 schematically shows an enlarged view of the vicinity of the magnetic layer (3) in FIG. 1.

θG is a columnar crystal grain body, and the film thickness of the magnetic layer (3) is 2000 mm.
In the case of about A, the particle size is about 200 to 500A. In addition, the well-known continuous deposition method, i.e.
When a vacuum evaporation method is used to continuously form a thin film while running a long substrate, the angle of incidence of evaporated atoms on the substrate (2) changes continuously, resulting in a columnar shape as shown in Figure 2. Curvature of the crystal grains can be seen.

Next, actual recording and reproducing characteristics recorded on the thin-film magnetic recording medium of the present invention using the ring-type magnetic head of the present invention will be described.

A polyimide film with a thickness of 1011 m is used as the substrate +21, and a T1 film with a thickness of 200 A is formed on this by a continuous evaporation method.
A ring-shaped magnetic head used in the present invention and a conventional ring-shaped magnetic head having the structure shown in FIG. Performed recording and playback. T1 mentioned above
The membrane is heated at 80C on top of it.

20 Used to increase the coercive force of the Cr film.

In addition, the saturation magnetization of the 80Co-20Or film is 400 um
/cc% The average inclination angle θ of the columnar crystal grains 01 is 300,
The coercive force in the direction in which the columnar crystal grains are inclined within the film plane is 3θ. Furthermore, a conventional ring-type magnetic head made of Mn--Zn ferrite with a gap length of 0.14 .mu.m was used. The ring-shaped magnetic head H having the structure shown in FIG.
r is the same Mn-Zn ferrite as the conventional one, but a magnetic thin film (
For example 5), an amorphous film made of Co--Nb--Zr with a film thickness of 3 pIn was used, and for the non-magnetic layer (6), SiO was used, and the film thickness of the non-magnetic layer (6), that is, the gap length was 0.14 μm. Each magnetic head has a gap width of 30 μm, a gap depth of 10 μm, and a coil winding number of 16 turns.

The table below shows the reproduction output when recording and reproduction were performed using these magnetic heads.

The signal recording density is 150 KFRP. Here: ↓50 KIPRP is 150,000 per inch
This is a recording state of a digital signal with 0 magnetization reversals.

The columnar crystal grains of the magnetic layer (3) +1 (the inclination direction of I is the first
It is in the direction indicated by θ in the figure, that is, in the direction of θ° by θ. Further, the reproduction output value when recording and reproduction is performed using a conventional ring-type magnetic head with the direction of movement of the medium relative to the head in the direction of arrow (8) in FIG. 1 is defined as odB. Furthermore, the same table shows that the conventional ring-type magnetic head mentioned above has a film thickness of 2000A and 80C! Also shown is the reproduction output when recording and reproduction is performed on a perpendicular magnetic recording medium made of an o-20Or alloy thin film.

Note that the coercive force of this 80 (!o -20Cr alloy thin film in the direction perpendicular to the film surface) is 800'''i5e.

From the table, it can be seen that the ring-type magnetic head of the present invention having the structure shown in FIG. When recording and reproducing is performed on a recording medium with the direction of relative movement in the direction of arrow (8) in Figure 1 and the direction of inclination of the columnar crystal grains in the opposite direction to the direction of movement of the medium, the conventional ring-type magnetic head It can be seen that when recording and reproducing are performed in the direction of relative movement indicated by arrow (8) in the tg1 diagram, a reproduction output that is dB higher than that in comparison can be obtained. Furthermore, when the relative movement direction is opposite to the arrow (8) in FIG. 1, the output is 3 dB lower than when it is in the direction of the arrow (8). Furthermore, compared to the case where recording and reproduction are performed on a perpendicular magnetic recording medium using a conventional ring-type magnetic head, the method of the present invention can obtain a reproduction output that is 10 dB higher.

Note that the inclination direction of the columnar crystal grains of the magnetic layer (3) is opposite to the direction indicated by θ in Fig. 1, and the ring having the structure shown in Fig. 1 is otherwise configured as shown in Fig. 1. When recording and reproducing using a type magnetic head, the arrow (8) in Figure 1
) When the thin-film magnetic recording medium is moved in the direction, the relative output is -5 dBs.When the thin-film magnetic recording medium is moved in the direction opposite to arrow (8) in Figure 1, the relative output is -2 dB.
B, and high reproduction output cannot be obtained.

The above experimental results can be interpreted as follows.

In contrast to the conventional ring-type magnetic head, the ring-type magnetic head of the present invention as shown in FIG.
A strong magnetic field is generated in the vicinity of the recording medium, and the gradient of the magnetic field strength in the medium running direction becomes steep, resulting in poor recording characteristics. In this region with a strong magnetic field, when a signal is recorded on a thin-film magnetic recording medium in which the columnar crystal grains are inclined with respect to the perpendicular to the film surface, the inclination of the columnar crystal grains and the direction of the head magnetic field are close to each other. , more sufficient recording is possible than the combination of a conventional ring-type magnetic head and a perpendicular magnetic recording medium. Furthermore, if the direction of relative movement of the thin film magnetic recording medium to the head is in the direction of arrow (8) in Figure 1, recording demagnetization will be smaller than in the opposite case, and a large residual magnetization will remain in the magnetic layer. Conceivable.

The playback output in the table above is expressed as a relative value, but the first
When using the ring-shaped magnetic head of the present invention having the structure shown in the figure, the absolute value of the reproduction output when the relative movement direction is in the direction of arrow (8) in Figure 1 is 450 μV/turn・rn/rn/
Seconds. This value far exceeds the reproduction output of conventionally reported perpendicular magnetic recording media. In addition, 4
50μ■/Turn・Simple・・/Second! : means that the head output is 450 μV per 1 turn of coil winding, 1 gap width, and 1 msa of relative speed between the medium and the head.

Effects of the Invention The present invention provides a ring-type magnetic head of the present invention, a thin-film magnetic recording medium of the present invention, a magnetic thin film provided on one side of the gap portion on the leading edge side, and a columnar magnetic recording medium of the thin-film type magnetic recording medium. By recording with the inclination direction of the crystal grains in the opposite direction to the moving direction of the thin film magnetic recording medium, a large short wavelength reproduction output can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of recording a signal on a thin film magnetic recording medium in which inclined columnar crystal grains are deposited using the ring type magnetic head of the present invention, and FIG. 2 is a schematic diagram of the thin film magnetic recording medium of the present invention. A structural diagram is shown. Engineering: Thin-film magnetic recording medium 2: Substrate 3: Magnetic layer in which columnar crystal grains are inclined with respect to the perpendicular to the film surface 4.
4': Magnetic material constituting the head core 5: Magnetic thin film with larger saturation magnetization than the magnetic material 6: Nonmagnetic layer 7: Winding wire
8: Arrow indicating the running direction of the thin-film magnetic recording medium relative to the ring-type magnetic head 9: Perpendicular to the film surface 10: Columnar crystal grain patent applicant Patent attorney Matsushita Electric Industrial Co., Ltd.
Isao Abe's visit to 100 yen 24 ramets) Figure 1

Claims (1)

[Claims] A ring-shaped magnetic head is provided in which a pair of magnetic materials are opposed to each other via a magnetic thin film having a higher saturation magnetization than the magnetic material, and a non-magnetic layer to form a gap portion, and a magnetic layer is deposited over the entire surface of the gap portion on the substrate surface. On the other hand, a thin film magnetic recording medium composed of inclined columnar crystal grains is brought into contact with its magnetic layer,
The direction of relative movement between the ring-shaped magnetic head and the thin-film magnetic recording medium is moved such that the magnetic thin film of the ring-shaped magnetic head is on the leading edge side, and the direction of inclination of the columnar crystal grains of the thin-film magnetic recording medium is adjusted. A magnetic recording method characterized by recording in a direction substantially opposite to the direction of movement.