JPH0418372B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a perpendicular magnetic recording medium with improved perpendicular magnetic properties.

Conventionally, as a manufacturing method for perpendicular magnetic recording media,
As seen in Publication No. 58-121134, a material to be evaporated is placed in a vacuum container, a magnetic material is placed directly below it,
A manufacturing method is known in which the magnetic material is obliquely irradiated with an electron beam using an electron beam generator, and the vapor of the magnetic material atoms is deposited on the surface of the material to be deposited directly above. When such an electron beam is irradiated obliquely onto the surface of a magnetic material, as shown in Figure 1, the part of the magnetic material a that is hit by the electron beam b is intensively evaporated, and the area corresponding to the direction of the electron beam b evaporates. A diagonally inclined concave c is formed, and the concave c functions like an obliquely oriented nozzle, and the evaporation d of the evaporating material is concentrated in the diagonal direction, resulting in a biased evaporation distribution, and the vapor can no longer be incident perpendicularly onto the material to be deposited, making it difficult to form a perpendicularly magnetized film.

Further, the perpendicular magnetic properties are better when the angularity appears better when the hysteresis curve of the perpendicular magnetic recording medium is measured, but the perpendicular magnetization film formed only from a magnetic material has dull angularity.

An object of the present invention is to eliminate such inconveniences, to provide a method for manufacturing a perpendicular magnetic recording material that can perform better perpendicular deposition of a magnetic material onto a material to be deposited, and has improved perpendicular magnetic properties. A vertical magnetization film is created by placing a material to be evaporated inside, placing a magnetic material directly below it, irradiating the magnetic material with an electron beam, and depositing the evaporated atomic vapor on the surface of the material to form a perpendicularly magnetized film. A method for manufacturing a magnetic recording medium is characterized in that an electron beam is perpendicularly irradiated onto a magnetic material, and the vapor that evaporates is oxidized by oxygen gas introduced into the vacuum container and deposited on the material to be evaporated.

Furthermore, it is an object of the present invention to provide a device suitable for carrying out the above-mentioned method, which has a simple configuration and can be manufactured easily. An evaporation source containing a magnetic material is installed in the vacuum container, an electron beam generator is installed on the side of the vacuum container, and an anti-deposition plate having vapor transmission holes is provided between the material to be evaporated and the evaporation source. In an apparatus for manufacturing a perpendicular magnetic recording medium, an electron beam deflection device is installed near the evaporation source to deflect an electron beam from an electron beam generator perpendicularly to the magnetic material, and the device is installed near the evaporation source to avoid the evaporation of the material to be evaporated. An oxygen gas introduction pipe is provided for supplying oxygen gas between the sources.

Next, an embodiment of the present invention will be described with reference to FIGS. 2 and 3.

In the drawing, reference numeral 1 indicates a vacuum container connected to a vacuum pump (not shown), and a synthetic resin is placed in the center of the vacuum container 1 and runs around a cooling can 2 at a constant speed in the direction of the arrow as it rotates. A material to be deposited 3 made of a manufactured tape is provided. Reference numeral 4 indicates a feed roll for the tape-shaped material to be deposited 3, and reference numeral 5 indicates a winding roll thereof. An evaporation source 7 consisting of a crucible containing a magnetic material 6 was installed directly below the material 3 to be evaporated. 8 is a transmission hole 9 located in the center between the evaporation source 7 and the evaporation source 7, which is located close to the running target material 3 on the lower end surface of the cooling can 2.
It is a horizontal anti-adhesion plate with a Reference numeral 10 indicates an electron beam generator attached to the side surface of the vacuum container 1 so as to face the magnetic material 6 and face diagonally downward.

The above configuration is not particularly different from a conventional perpendicular magnetic recording body manufacturing apparatus, but in the case of the present invention, the electron beam E generated by the electron beam generator 10 is
As shown in the figure, an electron beam deflection device 12 that generates a magnetic field that deflects the electron beam downward so as to be perpendicular to the magnetic material 6 is provided near the evaporation source 7, and the electron beam is directed between the material 3 to be evaporated and the evaporation source 7. An oxygen gas introduction pipe 11 for supplying oxygen gas was provided.

The electron beam deflection device 12 is composed of, for example, an electromagnet having a positive electrode and a negative electrode facing each other across the electron beam in a direction perpendicular to the trajectory of the electron beam E, and the oxygen gas introduction tube 11 is connected to a transmission hole in the deposition prevention plate 8. 9 is installed so as to supply oxygen gas from the side of the evaporation source 7 below, and the electron beam generated by the electron beam generator 10 is bent downward and made perpendicularly incident on the magnetic material 6 to oxidize it. The vapor of the magnetic material 6 was made to perpendicularly enter and adhere to the material to be deposited 3.

Next, an example of implementing the manufacturing method of the present invention using the above-described apparatus of the present invention will be described.

As the magnetic material 6, Fe, Co, Ni, or an alloy thereof is used. For example, Co is prepared as the magnetic material 6, and the electron beam E is emitted from the electron beam generator 10.
When the electron beam E is irradiated toward the magnetic material 6, the electron beam E is bent downward by the electron beam deflector 12 on the way and is incident perpendicularly on the magnetic material 6. The surface portion of the magnetic material 6 irradiated with the vertical electron beam melts and continues to evaporate vertically. More specifically, as shown in the third diagram, in the portion of the magnetic material 6 that receives the vertical electron beam E and melts and evaporates, a corresponding depression D extending in the vertical direction is generated.
Most of the atomic evaporation 6' of the magnetic material 6 is performed in the vertical direction, so there is no waste, and the perpendicularly magnetized film F
The perpendicular magnetic recording tape P is manufactured by adhering to the horizontal lower surface of the material 3 to be deposited. In this vapor deposition process, the vapor of the magnetic material 6 passes through a predetermined amount of oxygen gas introduced from the oxygen gas introduction pipe 11, and a part of the Co vapor becomes CoO, mixes with Co atoms at a certain ratio, and Co A perpendicularly magnetized film F having excellent perpendicular magnetic properties as described below is formed compared to a perpendicularly magnetized film with only the above-described structure.

Co 0.65, O produced with the above apparatus of the present invention
A magnetic recording tape based on the manufacturing method of the present invention having a perpendicular magnetization film with a thickness of 5000 nm and having a composition of 0.35;
A control magnet having a perpendicularly magnetized film with a thickness of 5000 nm and a composition of Co 0.65 and O 0.35 was manufactured in the same manner as above except that the magnetic material was irradiated with an electron beam at an angle of 45° without using an electron beam deflection device. The results of measuring the hysteresis curve with the recording tape are as shown in FIG. The solid line in the figure is the hysteresis curve of the magnetic recording tape manufactured by the manufacturing method of the present invention, and the dotted line is that of the control magnetic recording tape. As is clear from this, it is better to irradiate the magnetic material with an electron beam perpendicularly while introducing oxygen gas as in the present invention, than to irradiate the magnetic material obliquely with the electron beam while introducing oxygen gas. It can be seen that the squareness of the hysteresis curve is better than that of the previous one, and the perpendicular magnetic properties are excellent.

Furthermore, by oxidizing a part of the vapor of the magnetic material, a film with a two-phase structure of vertically grown ferromagnetic columnar particles and non-ferromagnetic oxide is formed on the surface of the deposition material 3, and the film becomes saturated. Magnetization decreases and perpendicular magnetic anisotropy due to shape magnetic anisotropy and crystal magnetic anisotropy increases, resulting in a magnetized film with good perpendicular magnetic properties.

In this way, when using the method of the present invention, the electron beam is irradiated perpendicularly to the magnetic material while introducing oxygen gas, so a perpendicularly magnetized film with better perpendicular magnetic properties than when no oxygen gas is introduced is produced. In addition to this, the magnetic material can be evaporated vertically from the evaporation source and the squareness of the hysteresis curve is better than when the electron beam is incident obliquely on the magnetic material while introducing oxygen gas. This has the effect that a perpendicular magnetic recording medium with even better perpendicular magnetic properties can be obtained, and the apparatus of the present invention has the effect that the method of the present invention can be carried out with a simple and inexpensive apparatus.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a magnetic material evaporation section explaining the conventional electron beam irradiation state, FIG. 2 is a cut-away side view of an apparatus according to an embodiment of the present invention, and FIG. 3 is an enlarged cross-sectional view of a part thereof. , FIG. 4 shows a comparison diagram of perpendicular magnetic characteristics. 1... Vacuum container, 3... Material to be evaporated, 6... Magnetic material, 7... Evaporation source, 8... Deposition prevention plate, 9... Transmission hole, E... Electron beam, 10... Electron beam generation Device, 11...Oxygen gas introduction tube, 12...Electron beam deflection device.

Claims (1)

[Claims] 1. A material to be evaporated is provided in a vacuum container, a magnetic material is placed directly below it, an electron beam is irradiated onto the magnetic material, and the evaporated atomic vapor is deposited on the surface of the material to be evaporated vertically. In a method of manufacturing a perpendicular magnetic recording medium that forms a magnetized film, an electron beam is perpendicularly irradiated onto a magnetic material, and the vapor that evaporates is oxidized by oxygen gas introduced into the vacuum container and deposited on the material to be deposited. A method for manufacturing a perpendicular magnetic recording medium, characterized by: 2. A material to be evaporated is placed in a vacuum container connected to a vacuum pump, an evaporation source containing a magnetic material is installed directly below it, an electron beam generator is provided on the side of the vacuum container, and the material to be evaporated and the evaporation source are placed on the side of the vacuum container. In an apparatus for producing a perpendicular magnetic recording medium having a structure in which an adhesion prevention plate having vapor transmission holes is provided between the two, an electron beam from an electron beam generator is directed perpendicularly to the magnetic material near the evaporation source. 1. An apparatus for manufacturing a perpendicular magnetic recording medium, comprising: an electron beam deflector for deflecting an electron beam in such a manner, and an oxygen gas introduction tube for supplying oxygen gas between the material to be deposited and the evaporation source.