JPS62241138A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To form a thin magnetic film having excellent coercive force and magnetic characteristics and to improve density and grade by diagonally depositing iron nitride ions formed from an ion source by evaporation in a high-vacuum vapor deposition chamber through an ion accelerating and decelerating systems. CONSTITUTION:The iron nitride ions formed by the ion source 1 are introduced through the acceleration system 2 and the decelerating system 4 into the vacuum deposition chamber 5, the inside of which is evacuated to a high vacuum. A mass separator 3 for selecting ion seeds is installed between the systems 2 and 4. The source 1 and the chamber 5 are made separate and the vapor deposition is executed in the high vacuum by controlling irradiation energy at >=45 deg. incident angle, by which the vapor deposition effect is improved and the thin magnetic iron nitride film having the high coercive force and excellent characteristic is obtd. The control of the phase to be formed by the vapor deposition selecting the specific ion kind is facilitated and the performance, stability and reliability of the thin magnetic iron nitride film are improved.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a magnetic recording medium having an iron-tin nitride film (Summary of the Invention) The present invention relates to a method for producing a magnetic recording medium having an iron-tin nitride film as a magnetic layer. In a method for manufacturing a recording medium, iron nitride ions are deposited at an oblique incidence on a non-magnetic medium in a vapor deposition chamber evacuated to a high vacuum with controlled irradiation energy, and at that time, iron nitride ions are separated into fine particles. However, by controlling the ion species to be deposited, the oblique incidence effect can be enhanced and high coercive force can be achieved, and the generated phase can be easily controlled, thereby improving the direction and stabilization of the quality of the iron nitride magnetic conductive film. By making this possible, it is possible to manufacture high-density and excellent magnetic recording media.

(Prior art) FOIBN2. is used as a ferromagnetic material for iron nitride. Fea
N.

These include ε-FexN (2<X≦3), which have excellent corrosion resistance and wear resistance, and have saturation magnetization values comparable to metals, making them suitable as magnetic recording media. Physics J 1984 (7) VOl, 11
, kl 9, pages 721 to 727.

When using this iron nitride as a recording medium, a coating method using acicular iron nitride magnetic particles obtained by nitriding acicular C particles may be considered, but in this case, characteristics superior to those of metal magnetic particles cannot be obtained.

In order to take advantage of the original characteristics of iron nitride, it is possible to make it into a conductive film.

Since iron nitride decomposes below its melting point, the method for forming the conductive film is reactive ion blating in a nitrogen gas atmosphere with - vaporized.

■Reactive sputtering in a nitrogen gas atmosphere using − as a target.

■Sputtering targeting iron nitride.

etc. are mainly used.

(Problems to be Solved by the Invention) ``Since iron nitride itself has low magnetocrystalline anisotropy, it is necessary to increase the coercive force by some method.

For example, it is known that oblique S deposition increases the holding force, but in the case of iron nitride, the activated reactive vapor deposition is performed in a nitrogen gas atmosphere, which weakens the oblique incidence effect and yields unsatisfactory results. I can't.

Further, in the conventional method, the iron nitride phase produced is not a single phase, but α phase Fc, Fe4N, and ε phase FexN (2<X≦3).

This resulted in a mixed phase of Fe2N, etc., resulting in unstable magnetic properties and deterioration over time.

Therefore, the present invention solves the above-mentioned drawbacks, imparts high coercive force to iron nitride, and further facilitates control of the generated phase, thereby achieving excellent characteristics of iron nitride ID film magnetic recording media! This makes it possible to create an image.

(Means for solving the problem) In the present invention, in order to impart high coercive force to the conductive magnetic layer using iron nitride and to facilitate control of the generated iron nitride phase, The iron nitride ions are introduced into a deposition chamber evacuated to a high vacuum via an ion acceleration and deceleration system, and the iron nitride ions with controlled irradiation energy are introduced onto a non-magnetic substrate placed inside the chamber. Vapor deposition is performed on corners of 45" or more.

(2) Furthermore, by separating the iron nitride ions, only specific ion species are selected and deposited.

(Function) As mentioned above, by separating the ion generation source and the deposition chamber to perform the deposition in a high vacuum, and by controlling the irradiation energy to perform the oblique deposition, the oblique deposition effect is enhanced and the retention force is increased. An iron nitride magnetic conductive film with high properties and excellent properties can be obtained.

Furthermore, if only specific ion species are selected and deposited, the generated phase can be easily controlled, improving the performance and stability of the iron nitride magnetic Fc film.
Improved reliability.

(Example) A detailed explanation will be given below with reference to the drawings.

FIG. 1 is a schematic diagram of a vapor deposition apparatus.

Iron nitride ions generated by the ion source 1 are introduced into a deposition chamber 5 which is evacuated to a high vacuum of about 10'Torr through an acceleration system 2 and a deceleration system 4.

A mass separator 53 for selecting ion species is installed between the acceleration system 2 and the deceleration system 4.

FIG. 2 schematically shows an example of an ion source.

This is an ion source called a Hiruneran type ion source, in which a discharge is performed in a nitrogen gas atmosphere between a target 6 made of iron and a positive 14i7, iron nitride or iron nitride ions are generated, and the filament 8 ionizes them efficiently. It will be done.

The iron nitride ions generated as described above are extracted from the ion source by the extraction electrode 9.

FIG. 3 shows the relationship between the saturation magnetization of the iron nitride and its conductive film produced at this time and the nitrogen partial pressure.

As the nitrogen partial pressure increases, the α phase 1b changes from the γ′ phase (Fe
4N), ε phase, ζ phase (r-e2N) and iron nitride phase with a high degree of nitridation are generated, and at the same time, the saturation magnetization decreases.

The ζ phase (Fe2N) is a nonmagnetic material.

The generated phase is difficult to be a single phase, and tends to be in a mixed state with adjacent phases.

FIG. 4 is a diagram showing the incident angle, and the angle formed by the perpendicular to the substrate 10 and the irradiated ion flow is the incident angle 11.

Glass was used as the substrate for vapor deposition, and the temperature was 10'T.
FIG. 5 shows the relationship between the incident angle and the coercive force (Oersteds) when irradiating at 30 cV with exhaust to 30 cV. Film thickness is 0.
It is 15m.

As shown in the incident angle-retention force characteristic curve 12 of the r-eaN and εFexN mixed phase and the incident angle-retention force characteristic curve 13 of FeaN made into a single phase by Mffi separation, the iron nitride conductor formed by the method of the present invention The film has a coercive force of 800 Oersted to 10.00 Oersted, which is a value sufficient for use in high-density magnetic recording media.

In addition, in the case of Fe4N single phase, the saturation magnetization is 135 emu/
9 and the coercive force is 820 oersted, the aging deterioration of saturation magnetization in 10 days is 13%, while Fe4N and ε
The saturation magnetization in the mixed state of phase rxN is 108 etau/
The coercive force was 790 oersted in g, and the deterioration of saturation magnetization over time in this case was -12% in 10 days.

As is clear from this, the thin Il made of FeaN, which has a single phase of J2 due to the quality; d separation! The magnetic layer exhibits better magnetic properties than a magnetic film-conducting layer made of iron nitride in a mixed state without mass separation, and can significantly reduce the deterioration of saturation magnetization over time.

(Effects of the Invention) In the present invention, iron nitride ions generated in an ion source are obliquely deposited in a deposition chamber evacuated to a high vacuum, and at that time, the deposited iron species can be controlled. By doing so, it is possible to form a stable iron nitride magnetic conductive film with superior coercive force and magnetic properties, and thus it is possible to manufacture a high-density, high-quality magnetic recording medium.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of the thermal bonding device, Fig. 2 is a schematic diagram of the ion source, Fig. 3 is a diagram showing the relationship between the generated phase, saturation magnetization, and nitrogen partial pressure, and Fig. 4 is a diagram showing the relationship between the generated phase, saturation magnetization, and nitrogen partial pressure. It is a diagram showing the angle of incidence,
FIG. 5 is a diagram showing the relationship between the incident angle and the holding force. 1... Ion source 2... Acceleration system 3... Temperature separator 4... Deceleration system 5... Vapor deposition chamber 6... Target 7... Anode 8... Filament 9...・Extraction electrode 10...Base 11...Incidence angle 12...144N and εFexN mixed phase incident angle-retention force characteristic curve

Claims (2)

[Claims] (1) It has an iron nitride conductive film characterized by depositing pre-generated iron nitride ions via an ion acceleration and deceleration system onto a non-magnetic substrate placed in a deposition chamber at an incident angle of 45° or more. A method for manufacturing a magnetic recording medium. (2) The method for manufacturing a magnetic recording medium according to claim 1, wherein only specific ions of iron nitride ions are selected and deposited by mass separation.