JPH0594611A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To provide a magnetic recording medium having high out-put power and excellent recording density characteristic by increasing coercive force from region thin in film thickness in a CoCr alloy film medium formed on a NiP coated substrate. CONSTITUTION:The NiP coating film 4 is formed on the substrate 1, furthermore the primary coating film 2, which contains Si or Si contg. element of one or more kind among B, Ta, Ti, P and C, is formed and the alloy thin film 3 containing mainly CoCr is formed on the primary coating film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic recording medium.

[0002]

2. Description of the Related Art In recent years, flexible magnetic disk devices,
Hard magnetic disk, audio magnetic tape device, V
Magnetic recording devices such as magnetic tape devices for TR are being miniaturized and increased in density. Higher densities in magnetic recording have mainly been realized by increasing the coercive force and thinning the magnetic layers of magnetic recording media. Conventionally used media are
This is a so-called coating type magnetic recording medium in which magnetic particles are dispersed in a polymer binder and coated on a base film. Recently, a recording system that can improve the recording density by about one to two digits has attracted attention. As the recording medium used here, a medium having magnetic anisotropy perpendicular to the film surface is used, and is formed by sputtering or vapor deposition. Perpendicular magnetic anisotropy, coercive force, and the like are magnetic characteristics that determine the recording density and reproduction output of these media. Regarding coercive force, high output is obtained by increasing coercive force.

[0003]

However, the NiP
The CoCr alloy film formed on the coated substrate has a small coercive force in a thin film region, and has a problem that the output is small when reproduced by a magnetic head. Although the coercive force becomes large in the region where the film thickness is large, sufficient characteristics could not be obtained due to recording / reproducing loss. The object of the present invention is to solve the above-mentioned conventional problems and to provide a CoCr film formed on a NiP-coated substrate.
It is an object of the present invention to provide a magnetic recording medium having a high coercive force in a thin film region, a high output, and an excellent recording density characteristic in a system alloy film medium.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to Si or Si with B, Ge, Ta, Ti, on a NiP coated substrate.
A base film containing at least one element of P and C is formed,
A magnetic recording medium is characterized in that an alloy thin film containing CoCr as a main component is formed on the underlayer. The magnetic recording medium film is an alloy thin film whose main component is CoCr.
The magnetic recording medium of the present invention is usually provided with a protective film and a lubricating layer on the magnetic recording medium. The underlying film and the magnetic recording medium are manufactured by the sputtering method, the vapor deposition method and the ion beam method.
There is a musputter method. Examples of the protective film include diamond-like carbon, graphite-like carbon, Si or silicon oxide film, and silicon nitride film.

[0005]

An alloy thin film containing CoCr as a main component is used as a magnetic recording medium, and as a base film for these, at least one element selected from Si, Si, B, Ta, Ti, P, and C is formed on a NiP-coated substrate. If a base film containing is used, the coercive force becomes large even in a thin film region.

[0006]

EXAMPLES Examples of the present invention will be described in detail below. Examples 1 to 7 and Comparative Example FIG. 1 shows the structure of the magnetic recording medium according to this example. An A1 alloy substrate is used as the substrate 1, and a NiP coating film 4 is formed on the substrate. On the NiP coating film 4, the Si or Si alloy base film shown in Table 1 was formed by the sputtering method to have the film thickness shown in Table 1. After that, CoCr having a film thickness of 500 angstrom was formed on each underlayer under the same sputtering conditions.
A Ta film was formed. In addition, as a conventional example, a CoCr film and a CoCrTa film are directly formed on a NiP-coated substrate without a base film.
A magnetic recording medium having a film formed was prepared and compared with the examples. Table 1 shows the coercive force perpendicular to the film surface of these magnetic recording media.

[0007]

[Table 1] ────────────────────────────────── Underlayer film thickness Perpendicular coercive force (angstrom) (Oe) ────────────────────────────────── Example 1 Si 600 1200 Example 2 Si-1 at% B 700 1350 Example 3 Si-1 at% Ge 800 1500 Example 4 Si-1 at% P 1000 1600 Example 5 Si-2 at% Ta 1000 1450 Example 6 Si-3 at% Ti 1000 1400 Example 7 Si-2 at% C 1000 1550 Comparative example NiP coated substrate No base film 800 ───────────────────────────────────

[0008]

As described above, according to the present invention, a magnetic recording medium having a high coercive force and a high density and a high output can be obtained even in a region where the thickness of the CoCr alloy thin film is small.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

[Explanation of symbols]

 1 Substrate 2 Base film of Si or Si alloy film 3 CoCr alloy film 4 NiP coating film

Claims (1)

[Claims] 1. Si or Si on a NiP coated substrate
Is formed with a base film containing at least one element of B, Ge, Ta, Ti, P and C, and an alloy thin film containing CoCr as a main component is formed on the base film. Magnetic recording medium.