JPS61260414A - Temperature sensitive magnetic recording medium and method for using said medium - Google Patents

Abstract

PURPOSE:To change the direction of the easy magnetization of a temp. sensitive magnetic material to the direction of the magnetic field impressed thereto and to increase the magnetic field to be impressed by providing a temp. sensitive magnetic material layer on a ferromagnetic material layer, impressing the external magnetic field thereto and irradiating laser light on such position at the same instant. CONSTITUTION:The ferromagnetic recording layer is obtd. by forming the ferromagnetic material layer 1 consisting of Fe, Co, Ni or the alloy thereof or ferrite to 1-1,000mum thickness by the conventional method such as vapor deposition, sputtering or plating on a substrate consisting of glass, resin, etc. A magnetic switch layer 2 consisting of the temp. sensitive magnetic material to be provided thereon is obtd. by forming Nd(Co.Fe.Al)5 of DyCo5 to 1-1,000mum thickness. The external magnetic field 3 is impressed to the recording position in the stage of recording; at the same time, the laser light 4 restricted to 0.1-10mum diameter is irradiated thereon to increase the temp. and to rotate 90 deg. the direction of the easy magnetization of the layer 2, by which said direction is changed to the direction of the impressed magnetic field 3 and the impressed magnetic field is increased. The vertical recording is thus executed to the ferromagnetic recording layer 1.

Description

[Detailed Description of the Invention] [Summary] A temperature-sensitive magnetic material layer is provided on the ferromagnetic material layer of a magnetic recording medium, and at the same time an external magnetic field is applied and a laser beam is irradiated to this position, the temperature-sensitive magnetic material is The direction of easy magnetization of is converted to the direction of the applied magnetic field to increase the applied magnetic field.

[Industrial application field]

The present invention relates to magnetic recording media.

[Conventional technology]

Conventional magnetic recording media have a layer of ferromagnetic material on top of a base layer,
Recording was performed using only an external magnetic field that magnetized the ferromagnetic material.

[Problem to be solved]

The magnetic field applied to the ferromagnetic material depends only on the external magnetic field.

[Means for solving problems]

The above problem is solved by a temperature-sensitive magnetic recording medium characterized in that a magnetic switching layer 2 made of a rare earth metal cobalt-based temperature-sensitive magnetic material is provided on a magnetic recording layer l made of a ferromagnetic material. At the same time as applying an external magnetic field 3 to the recording position, this position is irradiated with laser light 4 to raise the temperature and convert the direction of easy magnetization of the temperature-sensitive magnetic material to the direction of the external magnetic field 3, thereby increasing the applied magnetic field. This can be solved by a usage method characterized by this.

As the temperature-sensitive magnetic material, it is necessary to select a material whose temperature at which the direction of easy magnetization changes is higher than room temperature.
e-Ajris or DyCo are preferred.

Note that when reproducing information from this temperature-sensitive magnetic recording medium, when a laser beam is applied to the detection position at the same time as the detection head, the output at the recording position increases, and the output at the non-recording position also increases by the amount of this increase. During reproduction, the detection position may or may not be irradiated with laser light.

〔Example〕

Referring to FIG. 1, the temperature-sensitive magnetic recording medium of the present invention and its method of use will be described. First, the ferromagnetic recording layer is formed by depositing a layer of ferromagnetic material such as Fe, Co, Ni, an alloy thereof, or ferrite on a substrate made of glass or resin by a method such as vapor deposition, sputtering, or plating.
was formed to have a thickness of 1 to 1000 μm. The magnetic switch layer 2 made of a temperature-sensitive magnetic material provided thereon is Nd(Co-F
e'Al)S or DycO, with a thickness of 1 to 1000 μm
was formed.

During recording, an external magnetic field 3 is applied to the recording position, and a laser beam 4 with a diameter of 0.1 to 10 μm is irradiated to increase the temperature, thereby rotating the easy magnetization direction of the magnetic switch layer 2 by 90''. By changing the direction of the applied magnetic field 3, the applied magnetic field is increased to perform perpendicular recording on the ferromagnetic recording layer 1.

During playback, if the laser beam is irradiated in the same way as during recording,
Although a large output can be obtained from the recording position to the detection coil,
An output corresponding to this increase will also be generated from the non-recording position.

〔Effect of the invention〕

According to the present invention, the magnetization of the ferromagnetic material of the magnetic recording medium can be applied by adding a magnetic field generated by changing the direction of easy magnetization due to a rise in temperature of the temperature-sensitive magnetic material to an external magnetic field.

[Brief explanation of drawings]

FIG. 1(a) shows the recording method of the temperature-sensitive magnetic recording medium of the present invention;
(b) is an explanatory diagram of the reproduction method. l...Magnetic recording layer, 2-...Magnetic switch layer, 3
- External magnetic field, 4... Laser light, 5-... Strength of output magnetic field. □5, /”L5 (b) Reproduction method 3...external magnetic field

Claims (1)

[Claims] 1. A temperature-sensitive device characterized in that a magnetic switching layer (2) made of a rare earth metal cobalt-based temperature-sensitive magnetic material is provided on a magnetic recording layer (1) made of a ferromagnetic material. magnetic recording medium. 2. The temperature-sensitive magnetic recording medium according to claim 1, wherein the temperature-sensitive magnetic material is Nd(Co.Fe-Al)_5 or DyCo_5. 3. A magnetic switch layer made of a temperature-sensitive magnetic material based on rare earth metal cobalt is provided on a magnetic recording layer made of a ferromagnetic material to form a temperature-sensitive magnetic recording medium, and an external magnetic field (3) is applied to the recording position, The feature is that by irradiating this position with a laser beam (4), the temperature is increased and the direction of easy magnetization of the temperature-sensitive magnetic material is converted to the direction of the external magnetic field (4), thereby increasing the magnetic field applied to the recording position. How to use temperature-sensitive magnetic recording media.