JPS61137221A - Magnetic disk - Google Patents

Abstract

PURPOSE:To obtain a magnetic disk from which a lubricating agent is hardly strippable and which decreases hardly the number of CSS and has high reliability by constituting a magnetic recording medium in such a manner that static electricity does not accumulate thereon. CONSTITUTION:An antistatic layer 5 formed of a conductive oxide film is interposed between the magnetic recording medium 3 formed of a gamma-Fe2O3 film and a lubricating agent layer 4 to constitute the above-mentioned magnetic disk. The static electricity escapes quickly from the magnetic recording medium 3 and therefore the lubricating agent is hardly strippable and the trouble arising from a head crash is decreased. The magnetic disk having the high reliability is thus obtd. The film thickness of the thin conductive oxide film is preferably <=2,000Angstrom , as the spacing between the head and the gamma-Fe2O3 film is too wide if the film thickness is <=2,000Angstrom .

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk used in a magnetic disk device.

Figure 2 is a @ side view showing a conventional magnetic disk reported in IT31 to 1γ44 of the Electric Corporation Research and Practical Application Report Vol. 31 No. 9. In Figure 1, (1) is a disk-shaped aluminum alloy base. material, (2) is the underlayer of the magnetic recording medium made of alumite, and (3) is γ, which is the magnetic recording medium.
-Fe20. ．． The thin film (4) is a lubricant layer that prevents the head from adhering to the disk.

Currently, magnetic disk drives use a contact start/stop method for starting and stopping, and when starting and stopping, the magnetic head and the magnetic disk surface rotate while in contact, so electricity is generated due to M friction. . Also, during normal rotation (during recording/reproduction), the magnetic disk rotates at high speed and the magnetic head is floated by the air current.

Static electricity is also generated by friction between the air and the head or disk.

[Problem that the invention seeks to solve]

By the way, in conventional magnetic disks, the resistance of the γ-Fθ203 thin film that serves as the magnetic recording medium is large (resistivity is 103
(Ω・α), the film thickness is thin), and the static electricity generated by the above-mentioned coating was likely to accumulate. When a thin film is used as a recording medium, the lubricant peels off more easily than a coated medium due to good surface precision and resistance to chemical adsorption. Therefore, static electricity accumulates, and due to electrostatic force and discharge,
There was a problem in that the lubricant peeled off and the number of contact start/stop (aSS), which indicates the reliability of the magnetic disk, decreased. Generally, if the number of C8S is small.

Head crashes are more likely to occur, increasing the failure rate.

This invention was made to solve this problem, and it prevents static electricity from accumulating on fB magnetic recording media.
Therefore, the objective is to obtain a highly reliable magnetic disk in which the number of aSS operations is less likely to decrease due to the lubricant peeling off.

[Means for solving problems]

The magnetic disk according to the present invention has a lubricant layer between a magnetic recording medium formed of a γ-Fθ203 film and a lubricant layer.

An antistatic layer made of a conductive oxide film is interposed therebetween.

[Effect]

The antistatic layer in this invention has an electrical resistivity of γ-Fθ
Since it is significantly lower than a 2o3 thin film, static electricity is quickly dissipated and accumulation of static electricity is prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (5) is an antistatic layer. In addition to having low resistivity, the antistatic layer must also have excellent corrosion resistance and wear resistance, and a conductive oxide thin film is suitable.

Here, if it is on a conductive oxide thin film, the head and γ-F e20
This is because the space between the three films is too wide. The conductive oxide thin film referred to here is 5n02 + engineering n20. ,, Cd2S
nO4,' 0 (to thin film is shown, and impurities are added to lower the resistivity. For example, in the case of SnO, sb is added, and in the case of n20x, Sn is added, but 8n is added. Sn power when added to n203; o, s
The resistivity ρ is approximately 1Ω−α at wt%. Incidentally, deviation from the stoichiometric composition or addition of impurities to lower the resistivity does not adversely affect antistatic properties q1. Moreover, regardless of the type, the antistatic effect was of the same level. These thin films are widely put into practical use as transparent conductive films as essential industrial materials for optoelectronics, etc., using spray methods and OVD methods.

The film is formed using a sputtering method or the like.

In the magnetic disk configured as described above, peeling of the lubricant is reduced, and the resistivity of the antistatic layer is ρ75 (1Ω).

If it is less than α, the aSS test uses the conventional antistatic J
-The number of aSS was approximately twice as high as in the case without.

This shows that head crashes are reduced7.

〔Effect of the invention〕

As explained above, this invention is applied between a magnetic recording medium formed of a γ-Fe 203 film and a lubricant layer.

Since an antistatic layer made of a conductive oxide film is interposed, static electricity quickly escapes from the magnetic recording medium, which prevents the lubricant from peeling off, reducing failures due to head crashes and improving reliability. This has the effect of providing a magnetic disk with high hardness.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing a magnetic disk according to an embodiment of the present invention, and FIG. 2 is a partial sectional view showing a conventional magnetic disk. In the figure, (1) is a base material, 2) is an underlayer, (3) is a magnetic recording medium, (4) is a lubricant layer, and (5) is an antistatic layer.

Claims (1)

[Claims] A magnetic disk in which an antistatic layer made of a conductive oxide film is interposed between a magnetic recording medium made of a γ-Fe_2O_3 film and a lubricant layer.