JPH10124942A - Magnetic recording system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic recording system with which high-density recording is possible. SOLUTION: The medium of this magnetic recording system is a magnetic phase transition recording film 16. When the magnetic phase transition recording film in a ferromagnetic state is irradiated with blue laser proximity field light through an optical fiber having an aperture of 50nm in diameter at its front and, nonmagnetic recording pits 17 of 5nm in diameter are written by the phase transition from a ferromagnetic material to a nonmagnetic material. When the recording pits are irradiated with a red laser beam, the recording is erased by the phase transition from the nonmagnetic material to the ferromagnetic material. As a result, the recording bits turn to the nonmagnetic material and, therefore, the pit sizes may be reduced without restriction in the super- paramagnetic transition sizes and the high-density recording is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording system, and more particularly, to a magnetic recording system capable of stably recording small recording bits at high density.

[0002]

2. Description of the Related Art In a conventional magnetic recording system, the magnetization of a part of a continuous magnetic film whose magnetization is aligned in a specific direction is inverted to be used as a recording bit, or the shape and size are uniform for the purpose of noise reduction. The magnetic fine particles are arranged in an array on a non-magnetic substrate and used as recording bits.

[0003]

As the density of magnetic recording increases, the recording bit becomes finer and becomes a state called superparamagnetism, and the fluctuation of magnetization increases, making recording difficult or impossible. Even though, the recording state is destroyed due to aging. In addition, the process of producing a magnetic particle array having a uniform shape and size is complicated and time-consuming, and the medium is expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording system capable of suppressing the fluctuation of the magnetization even if the recording bit becomes fine and maintaining the recording state stably for a long period of time. It is an object of the present invention to provide a magnetic recording system capable of achieving the same low noise even without creating a.

[0005]

The object of the present invention is to provide a ferromagnetic material.
The problem can be solved by using a nonmagnetic phase change, and if necessary, by using a magnetic interlayer interaction via a nonmagnetic or antiferromagnetic film.

When a magnetic region is formed in a non-magnetic film by a recording head that induces a magnetic phase change, and this is used as a recording bit, all bits can be made to have the same shape and the same size. Noise can be eliminated, and an effect equivalent to a magnetic fine particle array medium involving complicated process steps can be obtained. At this time, when the recording bit size is small and superparamagnetism becomes a problem, a ferromagnetic layer is provided below the magnetic phase change film via a non-magnetic layer or an antiferromagnetic film, and the interaction between the recording bits is caused by magnetic interlayer interaction. Can be stabilized. Also, if a non-magnetic area is created in the magnetic film and this is used as a recording bit,
Since this bit is non-magnetic, there is no problem of superparamagnetism, and the bit size can be made sufficiently small.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic recording system according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a first embodiment of the basic configuration and recording state of a magnetic recording apparatus according to the present invention. The apparatus red semiconductor laser - The 1 and blue semiconductor laser - The 2, tip 10nmφ APA - optical fiber 5 having a tea 6, the thickness of _{10nm K 04 Co 16 [Fe (} CN) 6] 6.9H 2 O It is composed of a magnetic phase change recording medium film 7. When the light 3 from the red semiconductor laser 1 is guided to the optical fiber 5 and the near-field light 8 leaking from the aperture 6 at the tip is irradiated on the magnetic phase change recording film 7 in a non-magnetic state, the diameter becomes A 10 nm ferromagnetic recording bit 9 is written. When the recording bit is irradiated with blue laser light 4, the ferromagnetic state changes to a non-magnetic state due to a magnetic phase change, and recording can be erased.

FIG. 2 shows a second embodiment of the medium structure and recording state of the magnetic recording system according to the present invention.
K ₀₄ Co ₁₆ of the medium thickness _{5nm [Fe (CN) 6]} 6.9H 2 O magnetic phase change recording film 10, Cu film 1 having a thickness of 1.1nm located thereunder
1 and a 1 nm thick Fe film 12 located thereunder. When the magnetic phase change recording film in a non-magnetic state is irradiated with red laser light through an optical fiber having an aperture of 5 nmφ at the tip, a ferromagnetic recording bit 13 having a diameter of 5 nm is written. Since the recording magnetization 14 is strongly coupled anti-parallel to the magnetization of the Fe film by the magnetic interlayer interaction via the Cu film, the bit volume is 1/8 that of the first embodiment.
However, no magnetization fluctuation or magnetization reversal due to temperature rise is observed.

FIG. 3 shows a third embodiment of the recording state of the magnetic recording system according to the present invention. This medium is thick
5 nm K ₀₄ Co ₁₆ [Fe (CN) ₆ ] 6.9H ₂ O magnetic phase change recording film 16. By irradiating the magnetic phase change recording film in a ferromagnetic state with blue laser light through an optical fiber having an aperture of 5 nmφ at the tip, a nonmagnetic recording bit 17 having a diameter of 5 nm is written. Since this recording bit is a non-magnetic material, the bit volume is 1/8 smaller than that of the first embodiment,
In addition, despite the absence of the ferromagnetic stable layer as in the second embodiment, it is extremely stable against temperature rise. When the recording bit is irradiated with red laser light, the non-magnetic state becomes the same ferromagnetic state as the bit periphery due to the magnetic phase change, and the recording can be erased.

FIG. 4 shows a fourth embodiment of the recording state of the magnetic recording system according to the present invention. This medium is a FeO (111) film 1 having a thickness of 5 nm and having a ferromagnetic surface on a Fe base 18.
9 is a phase change magnetic recording film. 5 nm for this medium
When the ion beam of φ is irradiated, the irradiated area becomes amorphous and ferromagnetism is lost, and an amorphous bit 20 is recorded on the ferromagnetic substrate. Since this recording bit is made of a non-magnetic material, it is extremely stable against temperature rise as in the third embodiment. When the recording bit is irradiated with laser light and heated, the non-magnetic state becomes the same ferromagnetic state as the bit peripheral portion due to the amorphous-crystalline phase change, and the recording can be erased.

The bits recorded by the above four embodiments can be read by detecting the car rotation of the reflected near-field light or detecting the polarization of the electron flow flowing between the reading probe and the medium.

[0013]

As described in detail above, according to the present invention, since minute bits can be stably recorded, high-density recording is possible and its industrial value is very high.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a basic configuration and a recording state of an apparatus using a magnetic recording system according to the present invention.

FIG. 2 is a diagram showing an example of a recording state according to the magnetic recording method of the present invention.

FIG. 3 is a diagram showing an embodiment of a recording state according to the magnetic recording system of the present invention.

FIG. 4 is a diagram showing an embodiment of a recording state according to the magnetic recording method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 red semiconductor laser 2 blue semiconductor laser 3 red laser light 4 blue laser light 5 optical fiber 6 aperture 7 magnetic phase change recording medium film 8 near-field light 9 ... ferromagnetic recording bit 10 ... magnetic phase change recording medium film 11 ... Cu film 12 ... Fe film 13 ... ferromagnetic recording bit 14 ... magnetization 15 ... magnetization 16 ... magnetic phase change recording medium film 17 ... nonmagnetic recording bit 18 ... Fe base 19: FeO (111) film 20: Non-magnetic recording bit.

Claims (4)

[Claims] 1. A magnetic recording system for recording information in a magnetized state, wherein a magnetic phase change from a non-magnetic material to a ferromagnetic material or from a ferromagnetic material to a non-magnetic material is used. . 2. The magnetic recording medium according to claim 1, wherein a ferromagnetic region is formed on the non-magnetic material by using a phase change from a non-magnetic material to a ferromagnetic material, and this is used as a recording bit. Recording method. 3. The magnetic recording medium according to claim 1, wherein a non-magnetic region is formed on the ferromagnetic material by using a phase change from a ferromagnetic material to a non-magnetic material, and this is used as a recording bit. Recording method. 4. A magnetic phase change recording film is formed on a ferromagnetic film covered with a nonmagnetic film, and the magnetization of the magnetic phase change film is stabilized by magnetic interlayer coupling via a nonmagnetic or antiferromagnetic film. 4. The magnetic recording method according to claim 1, wherein the magnetic recording method is performed.