JPH0196823A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve crystal orientational property by ionizing the vapors of Co and Cr or projecting inert gaseous ions to the vapor flow thereof in the initial period of vapor deposition at the time of forming a perpendicularly magnetized film of Co-Cr by a vacuum deposition method on a substrate. CONSTITUTION:The vapor deposition is executed by ionizing a part of the whole of the vapors of Co and Cr by a high-frequency electrode or projecting the inert gaseous ions to the vapor flow of Co and Cr by using an ion gun in the initial period of the vapor deposition at the time of forming the perpendicularly magnetized film of the Co-Cr on the substrate consisting of a film of polyethylene terephthalate or Al, etc. The Co-Cr film of low coercive force is thus first formed and thereafter, the perpendicularly magnetized film of the Co-Cr is laminated thereon. More specifically, the substrate 1 is kept heated to about 150 deg.C by a heater 2 and the Co-10wt.% Cr alloy put into a vapor deposition source 3 is heated and evaporated by the electron beam from an electron gun 4 and after the vapor thereof is ionized by the high-frequency electrode 5, the perpendicularly magnetized film of the Co-19wt.% Cr is laminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording medium, and more particularly to a method for manufacturing a magnetic recording medium having a magnetic layer having excellent perpendicular magnetic properties.

[Conventional technology]

In recent years, as the density of magnetic recording has increased, research and development have been actively conducted on perpendicular magnetic recording systems in which recording and reproduction are performed by magnetizing perpendicularly to the film surface of a magnetic recording medium.

Regarding the perpendicular magnetic recording system, in order to further improve its performance, a hard magnetic layer made of a Go-Cr alloy or the like having an axis of easy magnetization perpendicular to the film surface of the magnetic recording medium is placed on a soft magnetic layer such as permalloy in a vacuum. A perpendicular magnetic recording medium with a two-layer structure in which layers are sequentially stacked using a film forming method such as vapor deposition or sputtering has been proposed [I.E.E.
Transaction on Magnetics, MG-1
5, 6 (November 1979) pp. 1456-145
8 pages (TEEE, Trans, Magne
tics, MAG15.6 (Nov, 1979)
pp 1456-1458) L (I.E.I., Transactions on Magnetics, MG-20, 1 (January 1984), pp. 99-1
Page 01 (IEEE, Trans, , Ma
genetics.

MAG20.1 (Jan, 1984) pp 9
9-101) ).

Although such a two-layer magnetic recording medium improves sensitivity during recording and reproduction, the crystal orientation of the perpendicularly magnetized film made of a Co-Cr alloy or the like formed on a soft magnetic layer such as permalloy is greatly disturbed. In particular, if the Co--Cr perpendicularly magnetized film is thin, sufficient magnetic properties cannot be maintained. To solve this problem,
Although attempts have been made to use a Co film or a nonmagnetic Co--Cr alloy film as the soft magnetic layer, it has not yet been possible to obtain a perpendicular magnetic recording medium that satisfies the magnetic properties.

[Problem that the invention seeks to solve]

As mentioned above, in the conventional perpendicular magnetic recording medium with a 2N structure consisting of a soft magnetic layer such as permalloy and a hard magnetic layer such as Go-Cr alloy, a Go-Cr perpendicular magnetization film formed on the soft magnetic layer is used. The crystal orientation of is disturbed,
Therefore, there was a problem in that the perpendicular magnetic properties deteriorated.

An object of the present invention is to solve the problems of the prior art described above, and to produce Co-Cr with excellent perpendicular magnetic properties by a vacuum evaporation method.
An object of the present invention is to provide a method for manufacturing a magnetic recording medium having a perpendicularly magnetized film.

[Means for solving problems]

As a result of various researches, the present inventors have found that Go-
When forming a Cr alloy film by vacuum evaporation method, Co and Cr
It has been found that by ionizing the vapor or irradiating the vapor flow with inert gas ions, the crystal orientation of the Co--Cr perpendicularly magnetized film to be formed is improved and the coercive force is reduced.

That is, the object of the present invention is to provide G on a substrate.

- When forming a perpendicularly magnetized Cr film by vacuum evaporation, some or all of the Go and Cr vapors are ionized using a high-frequency electrode, or an inert film such as Ar is ionized using an ion gun, etc., at the beginning of the evaporation process. Gas ions are irradiated into a Co and Cr vapor stream to deposit the ion-containing vapor stream onto the substrate.
By depositing an o-Cr film and forming a Co-Cr perpendicular magnetization film on it, the lower layer has a low coercive force and the upper layer has a high coercive force, and the crystal orientation is extremely high from the lower layer to the upper layer. This is achieved by forming a Go-Cr perpendicularly magnetized film with good perpendicular magnetic properties.

The magnetic recording medium manufactured by the method of the present invention can be made of polyethylene terephthalate, polyester, polyimide,
Films made of synthetic resins such as polyamide and polyvinyl chloride, or AQ and AQ alloys.

It includes various forms of magnetic recording media such as tapes, sheets, cards, disks, etc., which are based on metal plates such as Ti, Ti alloys, and stainless steel.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in more detail with reference to the drawings.

(Example 1) A perpendicular magnetic recording medium was manufactured using a vacuum evaporation apparatus having the structure shown in FIG. In the figure, a substrate 1 is heated to a temperature of 150° C. by a heater 2 before performing vapor deposition. The Go-10wt%Cr alloy loaded in the evaporation source 3 is heated and evaporated by the electron beam from the electron gun 4, and the evaporated vapor is ionized by the high frequency electrode 5 until the film thickness reaches 500 nm on the substrate 1. , and the deposition rate was 20 people/second. At this time, the high frequency power applied was 300W. Then, the application of high frequency power was stopped, and a perpendicularly magnetized film made of Go-19 wt % Cr having a total film thickness of 2,500 layers was formed at a deposition rate of 20 layers/second to produce a magnetic disk.

(Example 2) A perpendicular magnetic recording medium was manufactured using a vacuum evaporation apparatus having the structure shown in FIG. In the figure, a substrate 1 is wound up from a supply roll 9 via a rotating drum 10 onto a take-up roll 11 .

The rotating drum 10 is heated by a heater provided inside.
It is heated to 50°C. Co loaded in the evaporation source 12 and Cr loaded in the evaporation source 13 are evaporated by electron beam heating by the electron gun 4, and the film formation rate is increased to 30%.
As 0 people/second.

Go-19wt%C with a film thickness of 2500 on substrate 1
A perpendicularly magnetized film made of r was formed. At this time, the film was formed while irradiating Ar ions from the ion gun 14 provided at the initial incidence part of the vapor to be deposited on the substrate 1. The Ar ion acceleration voltage was 1 kV and the current was 30 mA.

(Comparative Example 1) A magnetic recording medium was produced by forming a G o -Cr perpendicularly magnetized film in the same manner as in Example 1, except that the vapor for vapor deposition was not ionized by the high-frequency electrode 5 at the initial stage of vapor deposition.

(Comparative Example 2) Instead of a 500-thick Go-Cr alloy film, which was deposited while ionizing the vapor for evaporation using the high-frequency electrode 5 in the early stage of vapor deposition, a SOO-thick Go (purity of 99.9%) was used. G was deposited in the same manner as in Example 1, except that G was vapor-deposited.

A magnetic recording medium was fabricated by forming a perpendicularly magnetized film consisting of:

Regarding the magnetic recording media produced in the above examples and comparative examples, the crystal orientation (dispersion Δθ20 of the C axis of X-ray diffraction) of the Co-Cr perpendicularly magnetized film and the perpendicular magnetic properties [initial deposition measured in the direction perpendicular to the film surface] Coercive force of membrane (500 people) He
The coercive force (Hcl) of the perpendicularly magnetized film above and formed was investigated. The results are shown in Table 1.

Table 1 As is clear from Table 1, the Co--Cr perpendicularly magnetized films of the present invention all have a low coercive force in the initially deposited film (500 layers) and a high coercive force in the upper layer.

It also has good crystal orientation and exhibits excellent perpendicular magnetic properties.

〔Effect of the invention〕

As explained in detail above, by ionizing the deposition vapor flow at the initial stage of film formation of the Co-Cr perpendicularly magnetized film of the present invention, the crystal orientation of the Go-Cr film can be significantly improved, and the perpendicular magnetic properties A magnetic recording medium having a perpendicular magnetization film with excellent properties can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the structure of a vacuum evaporation apparatus used in Example 1 of the present invention, and FIG. 2 is a schematic diagram showing the structure of a vacuum evaporation apparatus used in Example 2 of the present invention. l...Substrate 2...Heater 3...Evaporation source 4...Electron gun 5...High frequency coil
6...Matching box 7...High frequency power supply
8... Vacuum exhaust system 9... Supply roll 1o.
...Rotating drum 11... Winding roll 12.13.
...Evaporation source I4... Ion gun agent Junnosuke Nakamura Figure 1? 5-Shoukite Yukihoku 2nd figure 11--Puri R low too

Claims (1)

[Claims] 1. A method for manufacturing a magnetic recording medium by forming a magnetic layer containing cobalt and chromium as main components on a non-magnetic substrate directly or through an underlayer by a vacuum evaporation method, comprising: At the beginning of the deposition of the magnetic layer, a vapor flow containing cobalt and chromium as main components is ionized and deposited on the substrate, or the vapor flow is irradiated with inert gas ions to generate ions. After performing vapor deposition on the substrate as a vapor flow containing vapor, stopping ionization or ion irradiation of the vapor flow and continuing vapor deposition to form a perpendicularly magnetized film containing cobalt and chromium as main components. A method of manufacturing a magnetic recording medium characterized by: 2. The magnetic recording medium according to claim 1, wherein the means for ionizing the vapor flow for vapor deposition containing cobalt and chromium as main components is a high-frequency electrode provided in the vapor flow. Production method. 3. The magnetic recording medium according to claim 1, wherein the means for irradiating the vapor flow for vapor deposition containing cobalt and chromium as main components is irradiation with argon ions using an ion gun. Production method.