JPH03130904A - Magnetic recording method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording system capable of recording data at high density, and in particular to a magnetic recording system suitable for use in large-capacity recording for computers. Regarding the method.

[Prior Art] Conventionally, recording in the technical field of magnetic recording has been based on a longitudinal recording method that performs magnetization reversal along the direction of movement of a recording medium, as used in magnetic disk devices, magnetic tape devices, etc. It is used. In recent years, as storage capacity has increased, recording density has increased, and the interval between magnetization reversals on a recording medium has become narrower. However, this type of recording method has the problem that when the magnetization reversal interval in the in-plane longitudinal direction is narrowed, the so-called demagnetizing effect of magnetism becomes stronger, the residual magnetization on the recording medium weakens, and the reproduction output decreases. are doing.

Examples of conventional technologies that have solved these problems include:
“Bessatsu Science No. 79 (1986), p. 152~
The technique described on page 162 J (reprinted in the January 1980 issue) is known.

This prior art relates to a perpendicular magnetic recording method in which magnetization is reversed in the thickness direction of a recording medium.

The principle of perpendicular magnetic recording will be explained below with reference to FIG.

FIG. 2 is a diagram explaining the principle of perpendicular magnetic recording. Second
In the figure, 113 is a coil, 117 is a perpendicular magnetic recording film, 118 is a magnetic field concentration plate, 211 is a soft magnetic layer, 212 is a magnetic flux, and 221 is a recording magnetization section.

A recording medium for perpendicular magnetic recording is composed of a perpendicular magnetic recording film 117 and a soft magnetic layer 211 that are overlapped in the film thickness direction. When performing perpendicular magnetic recording on such a recording medium, as shown in FIG. 2(a), the recording medium's perpendicular magnetic field is A magnetic flux 212 is generated toward a magnetic field convergence plate 118 placed on the recording film 117 side.

As a result, the perpendicular magnetic recording film 117 within the magnetic flux 212
At this time, the magnetic flux 212 is converged by passing through the soft magnetic layer 211, leaving a recording magnetization portion 221 as shown in FIG. 2(b), and recording on the recording medium is performed.

[Problems to be Solved by the Invention] As explained with reference to FIG. 2, the prior art attempts to converge magnetic flux by providing a soft magnetic layer in the recording medium. As shown in FIG. 2(b), the shape expands from the magnetic field convergence plate 118 toward the coil 113, and it is difficult to reduce the bit area beyond a certain level, and it is difficult to increase the recording density beyond a certain level. In addition, there was a problem in that the override characteristics were deteriorated.

An object of the present invention is to solve the problems of the prior art and provide a magnetic recording method that eliminates the spread of the recording magnetization area and enables high-density recording by narrowing the entrance of magnetic flux entering the recording medium. It's about doing.

[Means for Solving the Problems] According to the present invention, the object is to form a superconducting film on the input surface of magnetic flux for recording to a recording medium to impart diamagnetic properties, and when recording, this superconducting film is This is accomplished by heating a portion of the membrane, thereby eliminating the diamagnetic properties of the heated portion and creating an entrance through which magnetic flux can pass.

[Function] The superconducting film exhibits diamagnetic properties and serves to protect the magnetic recording film from magnetic flux. When recording, a part of the superconducting film is heated by means such as a laser or friction to eliminate or weaken the diamagnetism of that part, and by applying a magnetic field there, Magnetic flux is passed through the magnetic recording film to magnetize it.

The magnetic flux passing through the magnetic recording film is collected by a magnetic field convergence plate made of a soft magnetic film, thereby suppressing its spread within the magnetic recording film, allowing high-density perpendicular magnetic recording to be performed on the magnetic recording film.

As the superconducting film, an oxide high-temperature superconductor recently discovered using a phase method can be used, and with this, the normal/superconducting transition of the superconducting film can be easily caused using liquid nitrogen. .

Furthermore, if a superconducting material that can be used at room temperature is developed in the future, by using such a material, the present invention can be carried out without using liquid nitrogen or the like.

[Example 1] Hereinafter, an example of the magnetic recording system according to the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a diagram illustrating an embodiment of the present invention.

In FIG. 1, 111 is a laser beam;
112 is a lens, 114 and 120 are magnetic fluxes, 1151 is a glass disk, 116 is a superconducting film, 1152 is an S+C)a thin film, 121 is a recording magnetization part, and other symbols are the same as in the case of FIG. .

An embodiment of the present invention shown in FIG. 1 is an example in which the present invention is applied to a disk-shaped recording medium.

In the recording medium of this embodiment, a perpendicular magnetic recording film 117 having a magnetic easy axis in the perpendicular direction is formed on a glass disk 1151 which serves as a protective film and a substrate, and a soft magnetic layer 211 is formed thereon. A conductive film 116 is formed, and S
It is constructed by forming an I○2 thin film. Lamination of each film to create the above-mentioned recording medium is mainly performed by sputtering technology.

The superconducting film 116 is L,,B1□Cu307-,,(L
o: Y and lanthanum series elements), B+zSr2C-,,
-+C,.

○y(n≧1), TQmB-2Cgo
An oxide high temperature superconductor such as -r Cuo Oy (m = 1.2.n≧1) can be used.

The heating light source and magnetic field application mechanism for recording may be the same as those used for magneto-optical disks, and in the embodiment of FIG. 1, as shown in FIG. 1(a), A lens 112 for condensing laser light 111 from a laser light source and a coil 113 for generating a magnetic field are shown.

The recording medium is filled with liquid nitrogen and
It is provided in an atmosphere cooled to below the normal-superconducting transition temperature of the superconducting film 116 of the recording medium, and its rotation is controlled by a compressor.

When recording on a recording medium such as that described above, FIG. 1(a)
As shown in FIG.
The diamagnetic property of the heated portion 119 is eliminated or weakened, and at the same time, a magnetic field for recording is generated by the coil 113. Of the magnetic field generated by the coil 113, the magnetic flux 120 that has passed through the heated portion 119 of the superconducting film 116, which has lost or weakened the diamagnetic property, passes through the perpendicular magnetic recording film 117 and passes through the magnetic field convergence plate. 118, the perpendicular magnetic recording film 117 is magnetized to form a recording magnetization section 121 as shown in FIG. 1(b). Also, out of the magnetic field generated by the coil 113, the magnetic flux 1 that cannot pass through the heated portion 119 of the superconducting film 116 that has lost its diamagnetic property or has its diamagnetic property weakened.
14 is blocked by the diamagnetic property of the superconducting film 116,
It cannot penetrate into the perpendicular magnetic recording film 117.

Therefore, in the embodiment of the present invention described above, the magnetic flux involved in recording is only the aforementioned magnetic flux 120, the size of which can be controlled by the size of the heated portion 119 of the superconducting film 116. By making the heating portion 119 small, extremely high-density magnetic recording can be performed.

Due to the film thickness effect of the superconducting film 116, the area of the portion 119 heated by the laser spot is the same on the surface that is directly hit by the laser and on the surface of the perpendicular magnetic recording film that is not directly hit by the laser. big. Therefore, the entrance area of the magnetic flux entering the perpendicular magnetic recording film can be made sufficiently smaller than the laser spot diameter by appropriately setting the thickness of the superconducting film 116. That is, by changing the thickness of the superconducting film, the recording density can be further increased.

The soft magnetic N211 in the embodiment of the present invention described above is
As in the case of the prior art, it acts to converge the magnetic flux 119 for recording, so that the size of the recording magnetization section 121 can be made smaller, and the recording density can be further improved. Can be done.

Note that in the embodiment of the present invention, this soft magnetic layer 211
Even if there is no magnetization, the recording magnetization section 121 can be made sufficiently small and the recording density can be improved.
It is also possible to reduce the cost of the recording medium without providing the soft magnetic N211 in the recording medium.

Furthermore, recording can be controlled by adjusting the output of laser light.

Recording by perpendicular magnetization of the perpendicular magnetic recording film 117 performed as described above is performed using the superconducting film 116 of the recording medium.
It can be reproduced by irradiating a laser beam from the side opposite to the one and reading the Kerr rotation.

Further, the reproduction of the recording can be performed by a magnetic head disposed on the side where the magnetic field convergence plate 18 is disposed,
In this case, the magnetic field convergence plate 18 can be used as the magnetic pole of the reading head or the τ portion of the magnetic pole.

[Effects of the Invention] As explained above, according to the present invention, the superconducting film provides
The entrance of magnetic flux to the perpendicular magnetic recording film can be restricted,
Since a smaller recording magnetization section can be created, high-density recording can be performed.

Furthermore, since the area around the entrance of the magnetic flux has diamagnetic properties, even if the magnetic field for recording is strengthened, it will not affect the surrounding recording film. Therefore, the thickness of the perpendicular magnetic recording film of the recording medium can be increased, and the output signal during reproduction can be increased.

Furthermore, according to the present invention, the size of the entrance where magnetic flux enters the perpendicular magnetic recording film can be made sufficiently smaller than the spot diameter of the laser beam by changing the film thickness due to the film thickness effect of the superconducting film. This makes it possible to perform higher-density recording.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining one embodiment of the present invention, and FIG. 2 is a diagram for explaining the principle of perpendicular magnetic recording. 111... Laser light, 112... Lens, 113... Coil, 114, 120, 21
2...Magnetic flux, 1151...Glass disk, 116...Superconducting film, 117...Perpendicular magnetic recording film, 1 work 8... ...Magnetic field convergence plate, 115
2...S r Oz thin film, 121.221...
. . . Recording magnetization section, 211 . . . Soft magnetic layer.

Claims (1)

[Claims] 1. In a magnetic recording system using perpendicular magnetization, a perpendicular magnetic recording film and a superconducting film are laminated, and the superconducting film is maintained at a temperature below the normal/superconducting transition temperature. By imparting diamagnetism to the conductive film and heating a part of the superconducting film, the diamagnetism of this part of the superconducting film is removed, and the perpendicular magnetic recording is performed from the part of the superconducting film from which the diamagnetism has been removed. A magnetic recording method characterized by passing magnetic flux through the film to magnetize the perpendicular magnetic recording film. 2. The magnetic recording method according to claim 1, wherein the means for heating a part of the superconducting film is a laser beam. 3. The superconducting film is L_nB_a_2C_u_3O_
7_-_σ (L_n: Y and lanthanum series elements), B_
i_3S_r_2C_a_n_-_1C_u_nO_y
(n≧1), Tl_mBa_2C_a_n_−_1C_
The magnetic recording system according to claim 1 or 2, characterized in that the magnetic recording system is an oxide high temperature superconductor such as u_nO_y (m=1, 2, n≧1).