JPS58212624A - magnetic disk - Google Patents

Abstract

PURPOSE:To prevent interference between adjacent tracks, by making the required parts of a magnetic thin film nonmagnetic by heating. CONSTITUTION:A magnetic thin film 2 of iron or the like is formed on a nonmagnetic substrate 1 by sputtering or other method in an Ar-oxygen atmosphere. While rotating the resulting magnetic disk, the space between data tracks is heated at 450-500 deg.C with a heat generating source such as laser attached to a head positioner. The heated parts are made nonmagnetic to form nonmagnetic tracks 4, and the magnetic tracks 3 are perfectly separated, so interference between the adjacent tracks can be prevented.

Description

Detailed Description of the Invention (a) Technical Field of the Invention The present invention relates to a magnetic disk in which a magnetic thin film is formed on a non-magnetic substrate, and more particularly to a magnetic disk in which required portions are made non-magnetic by heating. It is something.

(b) Prior Art and Problems In conventional magnetic disks, a magnetic thin film is formed by sputtering iron or iron alloy on a non-magnetic substrate, such as an alumite-coated AI [A1 alloy plate], and data tracks are formed on the magnetic thin film. Although servo tracks are configured, crosstalk between adjacent data tracks becomes a problem as the density of magnetic disks increases. In other words, there are problems such as track deviation due to the tracking accuracy of the head positioner, and off-track phenomena between the servo track and the data track due to differences in thermal expansion, and interference with adjacent track information, which greatly affects the characteristics. there were.

(C) Purpose of the Invention In view of the above-mentioned conventional problems, an object of the present invention is to provide a magnetic disk in which an independent data trunk is formed by heating a required amount of Mi in a magnetic thin film to make it non-magnetic. It is.

(d) Structure of the Invention In order to achieve the above-mentioned object, the present invention provides a magnetic disk in which a magnetic thin film is formed on a non-magnetic substrate by sputtering or the like with iron or iron alloy. This is achieved by locally heating the magnetic thin film and turning the heated portion into a non-magnetic material.

(e) Embodiments of the Invention Embodiments of the magnetic disk according to the present invention will be described in detail below with reference to the drawings.

Figure 1 shows the humidity characteristics forming the non-magnetic material according to the present invention, where the X-axis shows the relative value of saturation magnetization and the y-axis shows the warm temperature. A magnetic thin film (FesOi or f-F) formed on a magnetic substrate
6) When Of) is heated in the atmosphere, the saturation magnetization begins to decrease as shown in the figure when the temperature exceeds about 400°C.
4' It becomes zero at 50°C to 500°C, indicating an irreversible change. This is because the oxide portion of the magnetic thin film changes into a non-magnetic oxide (aF6gOs). In other words, it becomes a non-magnetic material.

FIG. 2 is a cross-sectional perspective view of the main part for explaining one embodiment of the magnetic disk according to the present invention, in which 1 is aluminium) IQ covered AI.
8 is a non-magnetic substrate made of an alloy or the like; 2 is a magnetic thin film made of a ferromagnetic oxide (Magnetite) (Fcs04) or a ferromagnetic oxide (Maghemai) (rFezes);
are magnetic area tracks and four non-magnetic area tracks.

Argon (Ar)-1! A heat source such as a laser is applied to a head positioner (not shown) while rotating a magnetic disk on which a magnetic thin film 2 is formed by sputtering iron (re) or an iron alloy on a non-magnetic substrate 1 in an element (02) W atmosphere. When the area between the data tracks is irradiated at a temperature of 450°C to 500°C as detailed in FIG. 1, the heated portion becomes a nonmagnetic material and forms a nonmagnetic region track 4 Eight magnetic area tracks (data tracks) can be completely independently prevented from interfering with adjacent tracks. The non-magnetic region 4 is made of non-magnetic material (α-
Therefore, there is no change in the shape of the medium (magnetic material, non-La material).

FIG. 8 is a plan view for explaining an application example of the magnetic disk according to the present invention, and FIG. 8 is a plan view and FIG. 5 is a magnetic material region, and 6 is a non-magnetic material region.

A magnetic disk having a magnetic thin film 2 formed on a non-magnetic substrate 1 is heated at 450° C. in spots by attaching a heat source such as a laser to a head positioner (not shown) while intermittently rotating the magnetic disk.
When irradiated at a temperature of ~500° C., the heated spot portion forms a non-magnetic region 6, and the non-magnetic region 6 and the magnetic region 5 are made to correspond to the information of It l II or 'I'. It is possible to record information by

(f) Explanatory power that exceeds the effect of the invention) As is clear, the magnetic disk according to the present invention has a higher magnetic nI than the conventional magnetic disk.
III! ! By making the data tracks independent and preventing interference between adjacent tracks, characteristics are improved, and
It is rJf capability to easily obtain a magnetic disk with high recording density.

[Brief explanation of drawings]

FIG. 1 is a temperature characteristic curve forming a non-magnetic material of a magnetic disk according to the present invention, FIG.
The figure is a Ca)&-1 plan view for explaining the present invention in detail, and (b) is a side view. In the figure, 1 is a non-magnetic substrate, 2 is a magnetic thin film, 8 is a magnetic area track, 4 non-magnetic area tracks, 5 is a magnetic area, and 6 is a non-magnetic area.

Claims (1)

[Claims] A magnetic disk characterized by a magnetic disk in which a magnetic thin film is formed by sputtering iron or iron alloy on a non-magnetic substrate.