JPH0991666A - Magnetic recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a medium having excellent corrosion resistance and durability by forming a magnetic film of specified compsn. having a colunmar structure on a base body in such a manner that the carbon density and the oxygen density are made higher in the peripheral part of the magnetic column than that in the center part. SOLUTION: A PET film 1 having 10μm thickness is mounted in an ion- assisted oblique vapor deposition device and the film 1 is travelled at 2m/min travelling speed. A Mg oxide crucible 15 is filled with Fe 16, which is vaporized by using a 30-kW electron gun 17 to deposit Fe vapor on the PET film 1. Further, methane and oxygen are supplied to a 400-W output ion gun 19 to irradiate the Fe film on the film 1 with carbon ion and oxygen ion to obtain a magnetic tape for VTR having 1850Å thickness of the magnetic film, 1400Oe coercive force Hc, 5300 G saturation magnetic flux density Bs, and Br/Bs=0.86. Thus, the obtd. Fe-C-O magnetic film has an oblique columnar structure on the base body and the carbon density and the oxygen density are made higher in the peripheral part than that in the center part of the magnetic column. The obtd. medium has excellent corrosion resistance and durability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium having an Fe-CO system magnetic film.

[0002]

In a magnetic recording medium such as a magnetic tape, due to the demand for high density recording, the magnetic film provided on the non-magnetic support is not a coating type using a binder resin. , A metal thin film type that does not use a binder resin has been proposed. That is, there has been proposed a magnetic recording medium having a magnetic film formed by a wet plating means such as electroless plating or a dry plating means such as vacuum deposition, sputtering or ion plating. This kind of magnetic recording medium is suitable for high-density recording because of its high packing density of magnetic material. As a magnetic material in this kind of metal thin film type magnetic recording medium, a magnetic metal such as a Co—Cr alloy or a Co—Ni alloy is used. However, since Co is a rare substance, the cost increases when used in a large amount.

Therefore, Fe is used as a non-Co metallic magnetic material.
Although Ni can be considered, Fe is inexpensive and
Since there are few problems of environmental pollution and the saturation magnetization is large, Fe is used as a magnetic material of a metal thin film type magnetic recording medium.
Started to be noticed. However, since Fe easily rusts,
It needs to be chemically stable. From this point of view, it has been proposed that the magnetic film be made of Fe _x N (Fe-N) or Fe-N-O. A magnetic recording medium composed of these magnetic films is said to have excellent corrosion resistance.

However, in recent years, it has been used under more severe environment, and further durability has been required. Therefore, an object of the present invention is to provide a magnetic recording medium having excellent corrosion resistance and durability.

[0005]

The object of the present invention is a magnetic recording medium comprising a support and a Fe—C—O based magnetic film provided on the support, wherein the Fe—C—O based magnetic film is provided. Is formed by an oblique column structure, and the magnetic recording medium is characterized in that the peripheral portion of the magnetic column has higher C concentration and O concentration than the central portion.

A magnetic recording medium comprising a support and a Fe--C--O magnetic film provided on the support, wherein the Fe--C--
In the Auger electron spectroscopic analysis of the O-based magnetic film (the sputtering direction is oblique to the magnetic film), the vertical axis represents the amount of Fe, C
Amount and O amount (Fe amount + C amount + O amount = 100%), the horizontal axis represents the sputtering time, and the Fe amount, C amount, and O amount each have a wavy pattern. Achieved by a recording medium.

In particular, there is provided a magnetic recording medium comprising an Fe—C—O type magnetic film provided on a support, said Fe—C
In the Auger electron spectroscopic analysis of the -O-based magnetic film (the sputtering direction is oblique to the magnetic film), the vertical axis represents the amount of Fe and C.
When the amount of oxygen and the amount of O (Fe amount + C amount + O amount = 100%) are plotted along the horizontal axis, the Fe amount, the C amount, and the O amount each have a wavy pattern, and the Fe amount has a peak. This is achieved by a magnetic recording medium characterized in that the C amount and the O amount correspond to valleys in the corresponding region, and the C amount and the O amount correspond to peaks in the region where the Fe amount corresponds to the valley.

A Fe—C—O type magnetic film is provided on a support, which is a magnetic recording medium, wherein said Fe—C—
The O-based magnetic film has an oblique column structure, and the C concentration and the O concentration are higher in the peripheral portion than in the central portion of the magnetic column, and the Auger electron spectroscopy analysis of the Fe—C—O-based magnetic film ( When the sputtering direction is diagonal to the magnetic film),
The vertical axis represents the amount of Fe, the amount of C, and the amount of O (Fe amount + C amount + O amount =
When the sputtering time is plotted on the horizontal axis, the Fe amount,
This is achieved by a magnetic recording medium characterized in that the C content and the O content each have a wavy pattern.

In particular, a magnetic recording medium comprising an Fe—C—O based magnetic film provided on a support, said Fe—C
The -O-based magnetic film has an oblique column structure, and the C concentration and the O concentration are higher in the peripheral portion than in the central portion of the magnetic column, and the Auger electron spectroscopy analysis of the Fe-C-O-based magnetic film is performed. In the (sputtering direction is oblique to the magnetic film), the vertical axis represents the Fe amount, C amount, and O amount (Fe amount + C amount + O).
Amount = 100%), and the sputtering time is plotted on the horizontal axis, Fe
Amount, C amount, and O amount each have a wavy pattern, and
According to the magnetic recording medium, the C amount and the O amount correspond to the valleys in the region where the e amount corresponds to the peaks, and the C amount and the O amount correspond to the peaks in the region where the Fe amount corresponds to the valleys. To be achieved.

Fe in the Fe--C--O magnetic film
Amount, C amount, and O amount are 50 at. % ≦ Fe amount ≦ 90 at. % 5 at. % ≦ C amount ≦ 35 at. % 5 at. % ≦ O amount ≦ 35 at. % Is preferably satisfied.

In particular, 60 at. % ≦ Fe amount ≦ 80 at. % 10 at. % ≦ C amount ≦ 25 at. % 10 at. % ≦ O amount ≦ 25 at. % Is preferred.

Further, in the magnetic recording medium of the present invention, F
A magnetic film other than the e-C-O based magnetic film may be provided, but there is no magnetic film used for recording / reproduction on the Fe-C-O based magnetic film, that is, the Fe-C-O based magnetic film. It is preferable that the magnetic film is the uppermost layer. In particular, the F specified by the present invention
It is preferable that the e-C-O based magnetic film is the uppermost layer.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The magnetic recording medium of the present invention is a magnetic recording medium comprising an Fe—C—O based magnetic film provided on a support, wherein the Fe—C—O based magnetic film is It has an oblique column structure, and the C concentration and the O concentration are higher in the peripheral portion than in the central portion of this magnetic column. Alternatively, in a magnetic recording medium in which a Fe—C—O based magnetic film is provided on a support, Auger electron spectroscopy analysis of the Fe—C—O based magnetic film (where the sputtering direction is relative to the magnetic film) (Diagonal direction), the Fe amount, the C amount, and the O amount (Fe amount + C amount + O amount = 100%) are plotted on the vertical axis, and the sputtering time is plotted on the horizontal axis. It has a wavy pattern. In particular, Fe-C on the support
A magnetic recording medium provided with a —O-based magnetic film, wherein Auger electron spectroscopy analysis of the Fe—C—O-based magnetic film (sputtering direction is oblique to the magnetic film)
The vertical axis represents the amount of Fe, the amount of C, and the amount of O (Fe amount + C amount + O amount =
When the sputtering time is plotted on the horizontal axis, the Fe amount,
In a region where the C amount and the O amount each have a wavy shape, and the Fe amount corresponds to the crests, the C amount and the O amount correspond to the troughs,
In the region where the Fe amount corresponds to the valley, the C amount and the O amount correspond to the peaks. Alternatively, it is a magnetic recording medium in which a Fe—C—O based magnetic film is provided on a support, wherein
The e-C-O based magnetic film has an oblique column structure, and the peripheral portion of the magnetic column has a C concentration and O
The concentration is high, and in the Auger electron spectroscopic analysis (the sputtering direction is oblique to the magnetic film) of the Fe—C—O system magnetic film, the vertical axis represents the Fe amount, the C amount, and the O amount (Fe amount + C amount + O). Amount = 100%), the horizontal axis represents the sputtering time,
The Fe amount, the C amount, and the O amount each have a wavy pattern. In particular, a magnetic recording medium comprising an Fe—C—O based magnetic film provided on a support, said Fe—C
The -O-based magnetic film has an oblique column structure, and the C concentration and the O concentration are higher in the peripheral portion than in the central portion of the magnetic column, and the Auger electron spectroscopy analysis of the Fe-C-O-based magnetic film is performed. In the (sputtering direction is oblique to the magnetic film), the vertical axis represents the Fe amount, C amount, and O amount (Fe amount + C amount + O).
Amount = 100%), and the sputtering time is plotted on the horizontal axis, Fe
Amount, C amount, and O amount each have a wavy pattern, and
In the region where the e amount corresponds to the crest, the C amount and the O amount correspond to the valley, and in the region where the Fe amount corresponds to the trough, the C amount and the O amount correspond to the crest.

Then, F in the Fe--C--O system magnetic film
The amount of e, the amount of C, and the amount of O are 50 at. % ≦ Fe amount ≦ 90 at. % 5 at. % ≦ C amount ≦ 35 at. % 5 at. % ≦ O amount ≦ 35 at. % Is satisfied.

The magnetic recording medium of the present invention is a method for producing a magnetic recording medium by forming a magnetic film on a support by an ion assist method, and comprises a vapor deposition step using Fe as an evaporation source substance. A collision step of causing carbon ions to collide with the vapor deposition Fe film and a collision step of colliding an oxidizing substance such as oxygen ions or oxygen gas with the vapor deposition Fe film, wherein the carbon ions and the oxidizing substance are vapor deposited Fe film. It is obtained by controlling the degree of collision and the amount of collision (supply condition). For example, as shown in FIG. 1, by implanting (irradiating) a mixed ion of carbon ions and oxygen ions from the side opposite to the traveling direction to a traveling support, the peripheral portion of the magnetic column can be moved to the peripheral portion rather than the central portion. Has a high C concentration and O concentration,
In the Auger electron spectroscopic analysis of the magnetic film (the sputtering direction is oblique to the magnetic film), the vertical axis shows the Fe amount, C amount, and O amount (Fe amount + C amount + O amount = 100%), and the horizontal axis shows the sputtering amount. Over time, an Fe—C—O based magnetic film having a wavy pattern of the Fe amount, the C amount, and the O amount can be obtained.

The wavy pattern referred to in the present specification refers to a pattern in which an amplitude variation of about 5% or more is recognized from the center virtual line except for the initial peak. Therefore, 2-3
If the vibration is as small as%, it is not regarded as a wavy pattern. FIG. 1 shows an ion-assisted oblique vapor deposition apparatus used in the present invention. In FIG. 1, 11 is a guide member, 12 is a supply side roll of the support 1, a take-up roll of 13 is the support 1, 14 is a shield plate, 15 is a crucible, 16 is Fe, 17 is an electron gun, and 18 is The vacuum container and 19 are ion guns. FIG.
In the above, the ion gun 19 is used to irradiate carbon ions and oxygen ions, but they may be irradiated separately, or
Instead of irradiating oxygen ions, oxygen gas may be supplied. Then, except that the supply of carbon ions and oxygen ions by the ion gun 19 is specified, the Fe-of Auger profile of FIG. A CO magnetic film can be obtained.

The magnetic recording medium according to the present invention thus obtained is shown in FIG. In FIG. 2, 1 is a support. The support 1 may be magnetic or non-magnetic, but is generally non-magnetic. For example, polyester such as polyethylene terephthalate, polyamide, polyimide, polysulfone, polycarbonate,
Polymer materials such as olefin resins such as polypropylene, cellulose resins and vinyl chloride resins, inorganic materials such as glass and ceramics, and metal materials such as aluminum alloys are used. An undercoat layer for improving the adhesion of the magnetic film is provided on the surface of the support 1 as needed. That is, to improve the adhesion of the magnetic film formed by dry plating by appropriately roughening the surface roughness, and to further improve the runnability by making the surface roughness of the magnetic recording medium moderate, for example, The undercoat layer is formed by providing a coating film containing particles such as SiO ₂ and having a thickness of 0.01 to 0.5 μm.

A coercive force Hc of 90 is formed on the undercoat layer by the ion assisted oblique vapor deposition apparatus shown in FIG.
0 to 1900 Oe, saturation magnetic flux density Bs is 3500 to 70
Fe-C-O with 00G and Br / Bs of 0.6 to 0.99
A metallic thin film type magnetic film 2 is provided. For example, 10
Fe is evaporated by resistance heating, high frequency heating, electron beam heating, etc. in a vacuum atmosphere of about ^-4 to 10 ^-6 Torr,
By depositing (evaporating) on the undercoat layer surface of the support 1, the Fe—C—O based magnetic film 2 can be formed in a thickness of 500 to 100.
It is formed to a thickness of 00Å, particularly 1000 to 4000Å. The angle of incidence during oblique vapor deposition is 30 ° to 80 °, preferably about 45 °.
The angle is between 70 ° and 70 °. During the deposition of Fe, carbon ions and oxygen ions are made to collide with the deposited Fe film. At this time, mixed ions of carbon ions and oxygen ions are implanted into the running support from the side opposite to the running direction. by this,
The C concentration and the O concentration are higher in the peripheral portion than in the central portion of the magnetic column.

A protective film 3 is provided on the Fe—C—O system magnetic film 2 and has a thickness of about 10 to 200 Å. The protective film 3 is composed of, for example, a carbon film such as diamond-like carbon or graphite, a silicon-containing film such as silicon oxide or silicon carbide, or the like. Among these, diamond-like carbon is preferable. The Auger profile shown in FIG. 3 is obtained when a diamond-like carbon film or a lubricant film described later is provided on the Fe—C—O based magnetic film. Therefore, in the Auger profile of FIG. 3, only C is present at the start of sputtering, and Fe and O are not detected. Then, as the sputtering progresses, Fe
And O are detected. Therefore, it is extremely difficult to determine where the surface of the magnetic film is, but the determination of where the surface of the magnetic film is is in accordance with general handling. In the present embodiment, when a carbon film such as a diamond-like carbon film is provided, it is considered that the film becomes a magnetic film from the point where the Fe amount and the C amount in the Auger profile are equal. Similarly, the lower surface of the magnetic film (interface on the support side)
Determining where is from will also follow general practice. In this example, when the support is a support containing C,
The point where the Fe content and the C content in the Auger profile are equal is considered to be the interface.

Reference numeral 4 is a lubricant layer provided on the protective film 3. That is, by applying a fluorine-based lubricant such as a hydrocarbon-based lubricant or perfluoropolyether, particularly a coating containing a fluorine-based lubricant by a predetermined means,
A lubricant layer 4 having a thickness of about 2 to 50Å, preferably about 10 to 30Å is provided. 5 has a thickness of 0.1 to 100 including carbon black or the like provided on the other surface of the support 1.
The back coat layer has a thickness of about 1 μm. The back coat layer 5 may be formed by depositing a metal such as an Al—Cu alloy.

[0021]

Example 1 A PET film 1 having a thickness of 10 μm is mounted on the ion assisted oblique vapor deposition apparatus shown in FIG. 1, and the PET film 1 is run at a running speed of 2 m / min.
Fe16 is contained in the crucible 15 made of magnesium oxide, the electron gun 17 of 30 kW is operated to evaporate Fe, vaporize Fe on the PET film 1, and supply methane and oxygen to the ion gun 19 of output 400 W ( Methane gas supply rate is 50 sccm, oxygen gas supply rate is 10 sc
cm) and irradiate the Fe film on the PET film 1 with carbon ions and oxygen ions, and a magnetic tape for 8 mm VTR of the type shown in FIG. 2 (thickness of magnetic film: 1850).
Å, coercive force Hc; 1400 Oe, saturation magnetic flux density Bs; 5
300G, Br / Bs; 0.86) was obtained.

Auger profile of this magnetic tape (measurement condition: electron gun; acceleration voltage 10 kV, emission current 10 nA, magnification 2000 times, etching condition; etching gas is argon, acceleration voltage 3 kV, ion current 3)
FIG. 3 shows the etching and sputter directions every 30 seconds at 00 nA, which are oblique to the metal magnetic film. This Fe-
In the Auger profile of the C—O magnetic film, the vertical axis represents the amount of Fe, the amount of C, and the amount of O (M amount + X amount + O amount = 100).
%), The horizontal axis represents the sputtering time, and the Fe content, C content,
And O amount each have a wavy pattern. In particular, Fe
Amount, C amount, and O amount each have a wavy pattern, and
In the region where the e amount corresponds to the crest, the C amount and the O amount correspond to the trough, and in the region where the Fe amount corresponds to the trough, the C amount and the O amount correspond to the crest. That is, in the oblique column structure of the Fe-CO system magnetic film, the C concentration and the O concentration are higher in the peripheral portion than in the central portion of the magnetic column. The Fe content in the Fe—C—O based magnetic film is 72 at.
%, C amount is 16 at. %, O amount is 12 at. %.

[0023]

Second Embodiment In the first embodiment, the supply amount of methane gas to the ion gun 19 is 40 sccm, and the supply amount of oxygen gas is 6 s.
8 mm VTR magnetic tape of the type shown in FIG. 2 (magnetic film thickness; 1800 Å, coercive force Hc; 1240 Oe, saturation magnetic flux density Bs; 6100 G, Br / Bs; 0.80) was obtained.

The Auger profile of this magnetic tape is shown in FIG. In the Auger profile of this Fe—C—O magnetic film, the vertical axis represents the Fe content, C content, and O content (M
(Amount + X amount + O amount = 100%) and the horizontal axis indicates the sputtering time, the Fe amount, the C amount, and the O amount each have a wavy pattern. In particular, in the region where the Fe amount, the C amount, and the O amount each have a wavy pattern, and the Fe amount corresponds to the mountain, C
In the region where the amount and the amount of O correspond to the valley and the amount of Fe corresponds to the valley, the amount of C and the amount of O correspond to the peak. That is, F
In the oblique column structure of the e-C-O based magnetic film, the C concentration and the O concentration are higher in the peripheral portion than in the central portion of the magnetic column. The Fe content in the Fe—C—O based magnetic film is 80 at. %, C amount is 12 at. %, O amount is 8 at. %.

[0025]

Third Embodiment In the first embodiment, the methane gas supply amount to the ion gun 19 is 70 sccm, and the oxygen gas supply amount is 15 sccm.
8 mm VTR magnetic tape of the type shown in FIG. 2 (magnetic film thickness; 2700 Å, coercive force Hc; 1450 Oe, saturation magnetic flux density Bs; 4900 G, Br / Bs; 0.90) was obtained.

The Auger profile of this magnetic tape is shown in FIG. In the Auger profile of this Fe—C—O magnetic film, the vertical axis represents the Fe content, C content, and O content (M
(Amount + X amount + O amount = 100%) and the horizontal axis indicates the sputtering time, the Fe amount, the C amount, and the O amount each have a wavy pattern. In particular, in the region where the Fe amount, the C amount, and the O amount each have a wavy pattern, and the Fe amount corresponds to the mountain, C
In the region where the amount and the amount of O correspond to the valley and the amount of Fe corresponds to the valley, the amount of C and the amount of O correspond to the peak. That is, F
In the oblique column structure of the e-C-O based magnetic film, the C concentration and the O concentration are higher in the peripheral portion than in the central portion of the magnetic column. The Fe content in the Fe—C—O based magnetic film is 65 at. %, C content is 20 at. %, O amount is 15 at. %.

[0027]

Fourth Embodiment In the first embodiment, the methane gas supply amount to the ion gun 19 is 25 sccm, and the oxygen gas supply amount is 12 sccm.
8 mm VTR magnetic tape of the type shown in FIG. 2 (magnetic film thickness; 2600 Å, coercive force Hc; 1290 Oe, saturation magnetic flux density Bs; 5850 G, Br / Bs; 0.82) was obtained.

The Auger profile of this magnetic tape is shown in FIG. In the Auger profile of this Fe—C—O magnetic film, the vertical axis represents the Fe content, C content, and O content (M
(Amount + X amount + O amount = 100%) and the horizontal axis indicates the sputtering time, the Fe amount, the C amount, and the O amount each have a wavy pattern. In particular, in the region where the Fe amount, the C amount, and the O amount each have a wavy pattern, and the Fe amount corresponds to the mountain, C
In the region where the amount and the amount of O correspond to the valley and the amount of Fe corresponds to the valley, the amount of C and the amount of O correspond to the peak. That is, F
In the oblique column structure of the e-C-O based magnetic film, the C concentration and the O concentration are higher in the peripheral portion than in the central portion of the magnetic column. The Fe content in the Fe—C—O based magnetic film is 80 at. %, C amount is 12 at. %, O amount is 8 at. %.

[0029]

Comparative Example 1 In Example 1, the amount of methane gas supplied to the ion gun in the direction perpendicular to the support was 45 sccc.
m, 8 mm VT of the type shown in FIG. 2 was carried out in accordance with Example 1 except that the supply amount of oxygen gas was 12 sccm.
R magnetic tape (magnetic film thickness: 1900Å, coercive force H
c; 1330 Oe, saturation magnetic flux density Bs; 6000G, B
r / Bs; 0.84) was obtained.

The Auger profile of this magnetic tape is shown in FIG. It should be noted that F in this Fe--C--O system magnetic film
The amount of e is 72 at. %, C amount is 14 at. %, O amount is 14
at. %.

[0031]

[Characteristics] Durability (reduction of 5 MHz output in still reproduction for 5 hours) and corrosion resistance (reduction of saturation magnetic flux density Bs after leaving at 60 ° C, 90% RH for 1 week) for the magnetic tapes of the above examples ), The results are shown in Table-1.
Shown in Table-1 Corrosion resistance ΔBs (%) Still durability (dB) Example 1-4-0.5 Example 2-6-0.7 Example 3-2-0.3 Example 4-8-0. 9 Comparative Example 1-11-1.9

[0032]

EFFECTS OF THE INVENTION Excellent corrosion resistance and durability can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a magnetic recording medium manufacturing apparatus.

FIG. 2 is a schematic sectional view of a magnetic recording medium.

FIG. 3 is an Auger profile of the Fe—C—O based magnetic film of Example 1.

FIG. 4 is an Auger profile of the Fe—C—O magnetic film of Example 2.

FIG. 5 is an Auger profile of the Fe—C—O magnetic film of Example 3.

FIG. 6 is an Auger profile of the Fe—C—O magnetic film of Example 4.

FIG. 7 is an Auger profile of the Fe—C—O based magnetic film of Comparative Example 1.

[Explanation of symbols]

 1 Support 2 Magnetic Film (Fe—C—O System Magnetic Film) 3 Protective Film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junko Ishikawa 2606 Kabane, Kaiga Co., Ltd., Haga-gun, Tochigi Prefecture Kao Stock Company (72) Inventor Katsumi Endo 2606 Kao, Kabushi, Kai-cho, Haga-gun, Tochigi Prefecture Shikisha Institute of Information Science

Claims (5)

[Claims] 1. A magnetic recording medium comprising an Fe—C—O based magnetic film provided on a support, wherein the Fe—C—O based magnetic film has an oblique column structure. A magnetic recording medium characterized in that the C concentration and the O concentration are higher in the peripheral portion than in the central portion of the magnetic column. 2. A magnetic recording medium comprising an Fe—C—O based magnetic film provided on a support, the Auger electron spectroscopic analysis of the Fe—C—O based magnetic film (where the sputtering direction is a magnetic film). In the oblique direction), the vertical axis represents the amount of Fe, the amount of C, and the amount of O (Fe amount + C amount + O amount = 10).
0%), the horizontal axis represents the sputtering time, and the Fe content and C
A magnetic recording medium characterized by having a wavy pattern in each of the amount and the amount of O. 3. A magnetic recording medium comprising an Fe—C—O based magnetic film provided on a support, wherein the Fe—C—O based magnetic film has an oblique column structure. The C concentration and the O concentration are higher in the peripheral portion than in the central portion of the magnetic column, and in the Auger electron spectroscopy analysis of the Fe—C—O based magnetic film (the sputtering direction is oblique to the magnetic film), the vertical axis And Fe amount, C amount, and O amount (Fe amount + C amount + O amount = 10
0%), the horizontal axis represents the sputtering time, and the Fe content and C
A magnetic recording medium characterized by having a wavy pattern in each of the amount and the amount of O. 4. In Auger electron spectroscopic analysis of a Fe—C—O system magnetic film (sputtering direction is oblique to the magnetic film), Fe axis, C quantity and O quantity (Fe quantity + C quantity +) are plotted on the vertical axis.
O amount = 100%), and the sputtering time is plotted on the horizontal axis.
e, C, and O have a wavy pattern,
The C amount and the O amount correspond to the valleys in the region where the Fe amount corresponds to the peaks, and the C amount and the O amount correspond to the peaks in the region where the Fe amount corresponds to the valleys. The magnetic recording medium according to claim 3. 5. The amount of Fe in the Fe—C—O system magnetic film,
The amount of C and the amount of O are 50 at. % ≦ Fe amount ≦ 90 at. % 5 at. % ≦ C amount ≦ 35 at. % 5 at. % ≦ O amount ≦ 35 at. %, The magnetic recording medium according to any one of claims 1 to 4.