JPH0210518A - Magnetic recording medium and magnetic recorder - Google Patents

Abstract

PURPOSE:To obtain a magnetic recording medium having a high recording density and high reliability by including a lubricant inside the magnetic recording film and a protective film, and providing the thin film of the lubricant on the protective layer. CONSTITUTION:The magnetic recording layer consisting of a metallic magnetic alloy is formed on a substrate, and the protective film is formed on the magnetic recording film. The magnetic recording film and the protective film internally contain a lubricant, and the thin layer of the lubricant is provided on the protective film. Consequently, when pores exist on the magnetic recording film and the protective film, and the lubricant exists in then, the internal lubricant compensates the reduction of the lubricant layer on a surface according to the reduction of the lubricant layer on the surface. Thus, the magnetic recording medium for the high density recording having excellent durability and corrosion resistance can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording medium used in a magnetic recording device and a magnetic recording device using the same, and particularly relates to a magnetic recording medium using a ferromagnetic metal thin film as a magnetic recording film. The present invention relates to a recording medium and a magnetic recording device using the same.

[Conventional technology]

Magnetic recording media whose magnetic recording film is a ferromagnetic metal thin film formed by vacuum evaporation method, molecular beam epitaxy method, cluster beam evaporation method, ion beam sputtering method, ion blating method, or various plating methods, etc. Although it has excellent magnetic properties suitable for density magnetic recording, since the magnetic recording film is a thin metal film, it is easily corroded and errors can occur.

Furthermore, since the hardness is low, there is a problem that the sliding reliability such as durability is inferior to that of conventional filler-containing coating media.

Conventionally, in order to solve this problem, alloys such as Co or Co-Ni with approximately 10 wt% Cr added to them were used as magnetic recording films to improve corrosion resistance, or ZAJINPODIUM ON MEMORY AND ADVANCED RECORDING TECHNOLOGIES Co., Ltd. S.M-A-R-T (San Jose, California, May 1986) WS3-B-2 No. 1
~25 pages (The sympo-sium on me
mory and advanced recordi
ng techno-10gies (S-M-A-R-
T) WS3-B-2p1~25 San Jose C
As described in A. May (1986), a carbon protective film is provided on the magnetic recording film, and a fluoroalkyl polyether polarity film is further applied thereon.

By forming a non-polar lubricating layer, the sliding reliability was increased to a certain level.

Furthermore, as described in Japanese Patent Application Laid-Open No. 61-69512, in a magnetic recording medium in which a carbon protective film is provided on a magnetic recording film, a lubricant film is formed so that the lubricant is impregnated into the bore of the carbon protective film. improved mechanical reliability.

[Problem to be solved by the invention]

The above-mentioned conventional technology did not give sufficient consideration to increasing the recording density of the magnetic recording medium. In other words, a high recording density magnetic recording medium must have a smooth surface in order to maintain the flying ability of the magnetic head. (7
If approximately 60 to 12,700 people are applied, the magnetic head and magnetic recording medium will stick together, causing the moving speed of the magnetic recording medium to become unstable or damaging the magnetic recording medium and the magnetic head.

To prevent this, if a thin lubricant layer is applied, the lubricant layer will gradually disappear as it is slid by the magnetic head.
Finally, there was a problem that the magnetic head would crash.

An object of the present invention is to provide a magnetic recording medium with high recording density and high reliability, and a magnetic recording device using the same.

[Means to solve the problem]

The above object is to provide (1) a magnetic recording medium having a magnetic recording film made of a metal magnetic alloy formed directly or via an underlayer on a substrate, and a protective film formed on the magnetic recording film; A magnetic recording medium characterized in that the magnetic recording film and the protective film contain a lubricant therein, and a thin layer of the lubricant is provided on the protective film. A magnetic recording film made of a metal magnetic alloy formed through a geological layer, and a protective film formed on the magnetic recording film, the magnetic recording film and the protective film containing a lubricant therein, and a magnetic recording device comprising at least a magnetic recording medium provided with a thin layer of lubricant on the protective film, a magnetic head, driving means for the magnetic head or the magnetic recording medium, or both, and a recording/reproducing circuit. This is achieved by at least one item.

The magnetic recording medium of the present invention has a ferromagnetic metal thin film formed as a magnetic recording film on a non-magnetic substrate directly or through an underlayer, further has a protective film on the magnetic recording film, and further has a lubricant. It is coated. As mentioned above, when the magnetic recording medium has a thin lubricant layer 1 on its surface, for example, a lubricant layer with a thickness of about 30 to 100 mm, this layer gradually disappears due to sliding with the magnetic head. However, if there are bores (pores) in the magnetic recording film or protective film and lubricant is present inside them, as the lubricant layer on the surface decreases, the lubricant inside the bore replenishes the decrease in the lubricant layer on the surface. do. Note that when there is a base layer, it is preferable that the base layer also have bores, since this increases the amount of lubricant impregnated.

However, when a nonmagnetic protective film is formed on a magnetic recording film having such bores and a lubricant is further applied on the protective film, the coverage of the lubricant on the film surface is less than 50%. This seems to be because the shape of the surface of the protective film also changes depending on the shape of the surface of the magnetic recording film. When the lubricant layer is thick, it is possible to apply the lubricant to the entire surface, but when it is thin as described above, the lubricant cannot be applied to the entire surface.

Therefore, the anti-sliding properties are unfavorable. It is therefore necessary to have a thin lubricant layer and a high coverage.

The above will be explained in more detail. A method for forming bores in the magnetic recording film, underlayer, and protective film is, for example, by forming the film by sputtering or vapor deposition at a gas pressure of 5 mTorr or more in Ar gas containing 0.1% (volume) or more of O2 gas. Obtainable.

- It is preferable to use the sputtering method for boat fishing.

The amount of 02 gas is preferably 10% or less.

If it exceeds 10%, oxidation of the film progresses. Also, the gas pressure is 3
If it exceeds 0mTorr, the film formation rate will be slow, so the
A gas pressure of less than mTorr is preferred.

- As an example, using Ar gas containing 0.2% of 02 gas,
At a gas pressure of 10 mTorr, a Cr underlayer (film thickness: 4000 mm), COo, on an AI2 alloy substrate (NLP treatment),
.

Ni0. ,. Zr6. A magnetic recording medium on which an ot magnetic recording film (g thickness: 500 g) and a carbon protective film (film thickness: 450 g) were formed was placed in trichlorotrifluoroethane containing 0.3% of hydroxylated or isocyanated perfluoroalkyl polyether. SIMS (secondary ion mass spectrometer: 5secondary ion mass spectrometer) when immersed
Figure 2 shows the results of analysis of the lubricant using a pectorometer. It can be seen from the detected amount of fluorine that the hydroxylated and isocyanated perfluoroalkyl polyether is impregnated into the protective film, magnetic recording film, and underlayer.

For example, as the gas pressure increases, the film compositions of the underlayer, magnetic recording film, and protective film become coarser (lower density), and the lubricant becomes more likely to be impregnated into the film. This suggests that the lubricant is contained in the gaps between the crystal grains.

The same magnetic recording medium as described above was manufactured by changing the film forming conditions, immersed in trichlorotrifluoroethane containing 0.5% lubricant, dried, and then heated to 80°C.

FIG. 3 shows the results of measuring changes in the amount of lubricant on the surface of the medium when the medium was maintained at high temperature and high humidity of 95% RH.

Measurements were made using reflective infrared absorbance at an incident angle of 70 degrees (1280 cm
-1) (hereinafter referred to as FTIR absorbance). FTIR absorbance is proportional to the amount of lubricant present on the media surface, and the absorbance of FTIR of 1×10-3 is 1.5 to 2 nm.
In the 0 figure, which is proportional to the amount of lubricant, 1 is H2 gas 0.
At 5 mTorr of Ar gas containing 2%, 2°3.4 is o2
Ar gas containing 0.4% gas, gas pressure 5,
The film was formed at 10.15 mTorr. 1 to 4
As the film structure becomes progressively rougher, the amount of lubricant on the surface decreases, and as the temperature and humidity are maintained, the lubricant inside the bore is discharged to the surface. That is, as described above, when a protective film is formed on the magnetic recording ridge where the bore exists and a lubricant is further applied thereon, the coverage of the lubricant on the film surface is small.

Therefore, in the magnetic recording medium of the present invention, lubricant is easily adsorbed on the surface of the protective film. - For example, by activating the surface of the protective film with oxygen, the lubricant is easily adsorbed on the surface. for example.

When the carbon protective film surface is subjected to plasma ash treatment in 0□ gas at 250m Torr, the O2 concentration on the protective film surface increases by 1.5 to 2.5 times compared to before treatment, and the surface is activated. This was confirmed using ESCA, Auger method, etc. This surface activation may be performed by plasma asher, spanner etching, ion implantation, or by chemically treating the surface with a chemical such as potassium permanganate. In addition, when performing activation treatment using plasma gas, as shown in Figure 4, when using a mixed gas containing 0□ and N2, the surface coverage by the lubricant increases and the sliding resistance and corrosion resistance are improved. This is particularly preferable because it increases. Here, the coverage rate was calculated from the contact angle value when a liquid such as glycerin was dropped onto the surface of the protective film.

In the present invention, the lubricant coverage on the surface of the protective film is 50%.
It is preferably at least 70%, more preferably at least 70%. The thickness of the protective film is preferably 100 to 600, more preferably 200 to 500. The material of the protective film may be carbon, carbide (WC, TaC, SiC, etc.), nitride (Zr), etc.
N, BN, etc.), oxides (A, O, Sin, etc.), etc. are used.

Further, FIG. 5 shows the relationship between the amount of lubricant on the surface of the protective film and the strength of the magnetic recording medium. The strength is expressed as the number of contact start-stops (CSS) by the MnZn ferrite head.6 In the present invention, the present invention is effective when the presence of lubricant is recognized in FTIR absorbance measurement at an incident angle of 40 to 80 degrees. In particular, as shown in the figure, the FTIR absorbance at 70 degrees is preferably in the range of I x 10-3 to 10 x 10-3, more preferably in the range of 1.5 to 8 x 10-'.

In media with FTIR absorbance of 30 x 10-3 or more,
The lubricant caused the head and media to stick together, which caused damage to the head gimbal, which was undesirable. The center line average surface roughness of this medium measured in the radial direction was 10 nm.

Furthermore, the magnetic recording medium of the present invention has a temperature of 30 to 100°C.
It is preferable that the amount of lubricant on the surface of the protective film does not change by more than 25% even if the protective film is kept in a high temperature and high humidity state of 50 to 100% RH for one hour. This is because when a large amount of lubricant in the bore is discharged to the surface due to high temperature and high humidity processing, it causes adhesion between the magnetic head and the magnetic recording medium.6 If there is excess lubricant that is easily discharged into the pore, the medium can be removed by soaking in lubricant solvent. Changes in the amount of lubricant on the surface of the protective film can be determined, for example, by changes in FTIR absorbance.

The nonmagnetic substrate in the present invention preferably has a smooth surface in order to achieve high recording density. That is, the center line average surface roughness of the surface is preferably 30 nm or less, more preferably 20 nm or less.

Further, the base layer may or may not be provided.

Co-Ni-Pt, Go-Pt, Co-F magnetic recording film
e-Pt, etc. 1 When forming a film by normal sputtering method, Co-Ni, Co-Ni-Fe, Go-Ni-Z
r, Go-Cr-8i, Go-Ni-Ti, Go-Cr
-Ta, Go-Ni-Hf, Go-Ni-Ru, Fe-
Ru, Fe-Zr, Fe-Ti, Co-Fe-Ni, G
When forming o-Zr, Co-Ti, etc. by oblique vapor deposition, oblique sputtering method, etc., it is not necessary to provide it.
Generally, Cr, Mo, W, or alloys containing these as main components, such as Cr-Ti and Cr-8j.

It is more desirable to provide an underlayer of Mo-Ti, Mo-Ni, W-Ti, Cr-Mo, etc. because the magnetic properties can be improved. Co-Cr, Co-Re, Go-Ti, Co-8i
etc., when vertically oriented, Co
-Ta-Zr, Co-Ta-Hf, Co-W-Zr, N
Go, such as i-Fe, Ni-Fe-Mo, etc.

It is more preferable to use a soft magnetic alloy containing at least one of Ni and Fe as a main component as the underlayer, since the reproduction output can be increased. In addition to these, various known underlayers can be used.

The thickness of the underlayer may be the thickness used in ordinary magnetic recording media, for example, about 100 to 5,000 layers. It is also preferable to form a bore in the base layer, since this allows the amount of lubricant to be impregnated into the base layer to be increased.

The magnetic recording film is made of a ferromagnetic metal such as a Co-based alloy.
Ni, Fe, Ti, Zr, Hf, Nb,
Ta.

An alloy consisting of at least one element selected from Y is used. In addition to these, ferromagnetic metals commonly used in magnetic recording films can also be used.

It is also possible to use a recording film in which the magnetic recording film contains oxygen, the concentration of which is higher on the surface side. When such a magnetic recording film is formed on a substrate by a sputtering method, an atmosphere of 11! It can be produced by gradually increasing the element concentration. For example, the above magnetic recording film can be formed by using Ar gas containing 0.1% of 02 gas as the atmospheric gas, gradually increasing the concentration of 02 gas, and finally changing to Ar gas containing 0.5% of 02 gas.

The lubricant preferably contains C or Si, and preferably contains a compound having an adsorbent substituent.

In particular, fluoroalkyl polyethers containing an unterminated group endowed with an anchor function are more preferable. Also, if the dipole moment of a molecule is μ and the molecular weight is Mw, then the dipole moment per molecule μ”/Mw is 18
Lubricants, especially fluoroalkyl polyethers, having an X 10-' Debye mole of 7 g or less are preferred.

The lubricant containing the unterminated group endowed with the above-mentioned anchor function is 1
For example, JP-A-61-155345. Japanese Patent Publication No. 62-652
26, JP-A No. 62-109229, etc.

The compound having an adsorbent substituent may be one that allows the lubricant to adsorb to at least one of the protective film, magnetic recording film, underlayer, and substrate.

For example, a perfluoroalkyl polyether having a substituent at its terminal end with an anchor function such as an ester group, an isocyano group, or a hydroxyl group is used in the present invention.

FIG. 6 shows that the use of a perfluoroalkyl polyether having an unterminated group endowed with an anchor function is superior to the use of a nonpolar perfluoroalkyl having no anchor function. In the figure, ester group,
Isocyano group and hydroxyl group mean a magnetic disk using perfluoroalkyl polyether having such substituents as a lubricant, and the curve is the value of the sliding test, and head crash occurs at the end of the line. , indicates that the magnetic disk has been damaged.

Note that an adsorbent lubricant and a nonpolar lubricant can be mixed and used at the same time. In this case, it is sufficient that the adsorbent lubricant is 40% by weight or more. Furthermore, two or more types of lubricants having adsorbent substituents having different adsorption powers, such as a hydroxyl group or an ester group, can be used as a mixture. In this case, they may be mixed in any ratio. Furthermore, compounds with an average molecular weight of less than 3000 and 3
It is preferable to use a mixture of 000 or more compounds.

In this case, it is more preferable that one of them is in the range of 40 to 60% by weight. In particular, it is most preferable to use a mixture of two or more lubricants having different substituents and different molecular weights.

Further, the magnetic recording device of the present invention includes the above magnetic recording medium, a magnetic head for magnetic recording/reproduction, for example, an Mn-Zn ferrite ring head, and an MIG using a metal magnetic film in the magnetic pole part.
The magnetic head, an inductive thin film magnetic head, an inductive/magnetoresistive composite head, etc., has at least driving means for a magnetic head or a magnetic recording medium or both, and a recording/reproducing circuit.

[Operation] When a magnetic recording medium has a thin lubricant layer on its surface, this layer gradually disappears due to sliding with the magnetic head. However, if there are bores in the magnetic recording film or protective film and lubricant is present inside the bore, as the lubricant layer on the surface decreases, the lubricant inside the bore will be discharged and replenish the decrease in the surface lubricant layer. It is thought that then.

However, when a nonmagnetic protective film is formed on a magnetic recording film in which such bores exist, and a lubricant is further applied on the protective film, the coverage of the lubricant on the film surface is low. This seems to be because the shape of the surface of the protective film also changes depending on the shape of the surface of the magnetic recording film. In the present invention, the surface of the protective film is activated to increase the coverage of the surface with the lubricant.

〔Example〕

An embodiment of the present invention will be described below in more detail based on the drawings.

Example 1 Outer diameter 130+smφ, inner diameter 40n+mφ, thickness 1.9m
Non-magnetic plating layers 2 and 2' made of N1-P and having a thickness of 15 μm were formed on a substrate 1 made of an AQ gold alloy having a thickness of 15 μm.

The surfaces of the nonmagnetic plating layers 2 and 2' are AQ and O.

The film was polished using a polishing tape or the like so that fine scratches were created in the circumferential direction, and the center line average surface roughness in the radial direction was 1 Onm and the film thickness was 10 μm. On this substrate with controlled surface roughness, a substrate temperature of 180°C and a DC input power density of 4 W/am were applied.
”, using Ar gas containing 0.1% oxygen and increasing the gas pressure to 10
A 400 nm thick Cr underlayer 3 was formed by sputtering using a Cr target under mTorr conditions.
3' was formed. On top of these base layers 3 and 3', Go-32at%Ni-
Using a 5at% Zr alloy target, the magnetic recording film 4,
4' was deposited to a thickness of 50 nm. Next, on the magnetic film 4, a protective film 5, 5' made of C with a thickness of 40 nm is formed by sputtering under the same conditions as above, and then 0□
The surface was modified by etching C to a thickness of 5 nm in N2 gas (200 m Torr) containing 50% of C, and a magnetic disk was obtained. with this base.

Furthermore, a lubricating layer was formed by immersing a perfluoroalkyl polyether lubricant in a solution of 0.5% 1 dissolved in trichlorotrifluoroethane and using the dip method. ′
This magnetic disk was further immersed in trichlorotrifluoroethane, and the medium from which excess lubricant was removed was subjected to SIMS.
Analysis of F atoms in the depth direction revealed that the distribution was almost the same as that shown in Figure 2. In other words, the strength of F atoms in the lubricant increases from the surface of the protective film, the interface between the protective film and the magnetic recording film, to the inside of the magnetic recording film, and therefore the lubricant is retained not only on the surface of the protective film but also inside the film. I know that there is. Note that this tendency is the same for the magnetic recording medium before cleaning with trichlorotrifluoroethane.

In addition, the lubricated magnetic disk was measured at an incident angle of 40 to 80° using a Fourier transform infrared absorption quadrature meter (FTIR).
When the reflection infrared spectrum of the lubricant was measured, another peak at about 1280 am-1 due to the CF bond contained in the lubricant molecules was obtained, which confirmed the presence of the lubricant in the surface layer. The coverage rate of the lubricant on the medium surface was about 80%.

Furthermore, similar magnetic recording media were manufactured under the same conditions except that the gas pressure during sputtering was changed to 5 m Torr and 15 m Torr.

The magnetic recording medium thus produced was subjected to a C8S test, and its durability was evaluated by measuring the number of C8S until the head crashed. Corrosion resistance was evaluated by measuring the loss in magnetization Ms. Further, the density of the magnetic recording film of this magnetic disk was evaluated from the fluorescence X-ray intensity. Table 1 shows the results.
Shown below.

Table 1 As shown in Table 1, it was found that the lower the apparent density of the magnetic film, the more lubricant it can hold, resulting in superior durability and corrosion resistance.

Example 2 Outer diameter 130mmφ, inner diameter 40mmφ, thickness 1.9mm
15μm of non-magnetic 12wt% on Al1 alloy substrate 1 of
P--Ni plating layers 2 and 2' were formed, and fine scratches were made in the circumferential direction so that the average surface roughness at the center line was 10 nm to obtain a nonmagnetic substrate. On this substrate, by -DC sputtering method, the substrate temperature was 100℃, ○, 0, 2voQ
% Ar gas pressure 10m Torr, DC input power 2W/am'', Cr, Cr, Tia, 1 alloy,
Mo, Mo6. gCro, , alloy, W or W, , C
ro, 1 alloy as base layers 3 and 3', respectively, 350n
m, and then COo, , Ni, , under the same conditions.
Z ro, os magnetic layers 4, 4' are 50 nm thick.

Finally, C protective films 5 and 5' were formed to a thickness of 40 nm under the same conditions, and plasma treatment was performed for 30 seconds in O2 gas containing 2% N2 and a pressure of 100 mTorr. Next, a perfluoroalkyl polyether having a molecular weight of 2,000 and containing an OH group was added to a 0.
The disk was immersed in trichlorotrifluoroethane containing 2% to prepare a magnetic disk.

When this disk was evaluated by FTIR at an incident angle of 70'', the magnetic disk using any underlayer was 1280 aa.
-” an infrared absorption peak was observed, and the absorbance was 2 to 4.
Furthermore, when these disks were analyzed using the SIMS method, it was found that the lubricant was impregnated into the magnetic recording film and underlayer of each disk.
It showed a C8S intensity of 30 times or more. The lubricant coverage on the surface of these magnetic disks was about 80%. Cr
-Ti alloy.

Those using Cr as a base are Mo and Mo alloys.

The coercive force was about 30% to 40% higher than when W and W alloy were used, and high recording density was achieved.

Example 3 Outer diameter 150! AQ alloy substrate 1 with IIIφ and 211 mm thickness
A non-magnetic 11wt% P-Ni plating layer 2, 2' with a thickness of 20 μm is formed on the surface, and its surface has a center line average surface roughness of 15
A non-magnetic substrate was prepared by making fine scratches in the circumferential direction so as to have a thickness of nm. On this substrate, by DC sputtering method, a substrate temperature of 120° C. 902, 0.2 voQ%, an Ar gas pressure of 15 m Torr containing H2 of 0.1 voQ%, D
Film thickness 250nm at C input power 5W/am”
After forming the Cr underlayers 3 and 3', a 40 nm thick Cr underlayer 3,3' is formed.
o. ,,Ni,,4. Coo,.

Ni, 1. , zro, os , Co, , , Cr, ,
Zr, 5°Co, ,Fe, 2. Zr... ,,
Go,,,,Ni,,2pt. ,,.

Go. ,,, Cr0,1Ta0. . s, Coo,
, Ni0.2Ta, . . . magnetic recording films 4, 4' and C protective films 5, 5' with a film thickness of 50 nm were formed, and a plasma ashing process was performed for 30 seconds using 02 gas containing 80% N2 at 50 mTorr. did.

Next, it contains -COOH group and -OH group at the same time, has a molecular weight of 5000, and has a tt''/Mw of 15 x 10-'
The disk was immersed in trichlorotrifluoroethane containing 0.3% perfluoroalkyl polyether (Debye mol/g), pulled out, and then re-immersed in pure trichlorotrifluoroethane to remove excess lubricant. It was removed and used as a magnetic disk.

When this disk was evaluated by FTIR at an incident angle of 70°, it was found that both magnetic recording films had 1280 e1m-
``There is an infrared absorption peak nearby, and the absorbance is 6~
It was in the range of 8x10-3. When the distribution state of the lubricant in the disk was analyzed using the SIMS method, it was found that the lubricant was adsorbed and remained not only on the surface but also in the magnetic layer and underlayer. Furthermore, when five magnetic disks with a lubricant surface coverage of approximately 90% were left in a high temperature and high humidity environment of 60°C and 90% RH for one week, the absorbance due to F'rIR was constant, and furthermore, Almost no increase in errors was observed, demonstrating excellent corrosion resistance. In particular, Co N x
Z r +CoCrZr, CoCrTa, CoNiPt
No errors occurred when using the ternary alloy. In addition, for both disks, when a magnetic head was placed on the disk and a load of 10 g was applied from above, the adhesion force, which is the resistance force when the head was moved, was good at less than 5 g, and showed a C8S strength of 30 times or more. . Here are three more copies of this medium.
50%R at 0℃, 50℃, 80℃, 90℃, respectively
H, 80%RH, 95%RH humidity, 1°5.20
We evaluated the change in FTIR absorbance after leaving it for a time of ±2.
The amount of variation was less than 0%, and therefore the adsorption force was also approximately the same, less than 6 g.

Example 4 Outer diameter 130+imφ, inner diameter 40i+mφ, thickness 1.9m
15μm of non-magnetic 12wt% on top of the AQ alloy substrate 1 of m
P--Ni plating layers 2 and 2' were formed, and fine scratches were made in the circumferential direction so that the center line average surface roughness was 10 nm to obtain a nonmagnetic substrate. A DC sputtering method was applied to this substrate at a substrate temperature of 150'C, O, O, O, 1voQ% Ar gas pressure of 7mTorr, and DC input power of 2W/am.
Cr underlayers 3 and 3' were formed to a thickness of 400 nm, then magnetic layers 4 and 4' of COa, ss Nio, ao zrO, and lli were formed to a thickness of 5° under the same conditions, and finally a C protective film 5 was formed under the same conditions. . Next, the disk is immersed in trichlorotrifluoroethane containing 0.2% perfluoroalkyl polyether having a C00CR□ group and a molecular weight of 4000, and then immersed in pure trichlorotrifluoroethane to remove excess. The lubricant was removed and a magnetic disk was created.

When this disk was evaluated by FTIR at an incident angle of 70', an infrared absorption peak was observed at 1280ca+-', and the absorbance was 3X10-'. Also, S.I.
As a result of analysis using the MS method, not only the surface.

The presence of lubricant was observed in all of the protective film, magnetic recording film, and underlayer. In addition, the surface lubricant coverage is approximately 80
%Met.

At this time, the adhesive strength of the disks was all 4 g or less, which was good, and the C8S strength was also 30 times or more, showing good results.

Example 5 A non-magnetic 11.5wt% P-Ni plating layer 2 with a weight of 15μ is placed on an AΩ alloy substrate 1 having an outer diameter of 150+mm and a thickness of 2μ.
2' was formed, and its surface was provided with fine scratches in the circumferential direction so that the center line average surface roughness was 8 μm to obtain a nonmagnetic substrate. On this substrate, an Ar gas pressure of 12 mTo containing 0.25% of 0□ was applied by RF sputtering at a substrate temperature of 120°C.
After forming Cr underlayers 3 and 3' with a thickness of 250 nm with input power of 3 W/am'', a layer with a thickness of 4゜n was formed under the same conditions.
Co of m, Ni0. ,, Ti,,,, and CO(
1.s Nio, 33ZrO, aff layer was formed, and then the input power was lowered to 1.5 W/e11" to reduce the film thickness to 20 nm.
m Co,, GNi,..., Tio,. ,YaCo o
, @ N x o , 3 a Z r o , o
Further layers were formed thereon to form magnetic recording films 4, 4'. In addition, the film thickness is 25% with input power of 5W/elm.
B, B4G protective films 5, 5' of nm are formed, and the surface is coated with N.
After plasma treatment with Ar gas at 20 mTorr, the disc contains 0.5% of the above-mentioned perfluoroalkyl polyether lubricant (molecular weight 500) containing non-polar but adsorbent unterminated groups. After being immersed in trichlorotrifluoroethane and pulled up, it was immersed again in pure trichlorotrifluoroethane to remove excess lubricant, and then a magnetic disk was obtained.

The surface lubricant coverage of the above disk was approximately 90%, and as a result of SIMS analysis, the presence of lubricant was found not only on the surface but also in the protective film, magnetic recording film, and underlayer. Further, when evaluated by FTIR at an incident angle of 70'', an absorbance of 6Xl was found at a position of approximately 1280011-''
An O-3 peak was observed.

Further, although this disk was left in a high temperature and high humidity bath at 60° C. and 80% RH for 15 hours, no increase in the FTIR peak was observed, and the adhesive strength was reduced to 5 g or less.

As mentioned above, analysis using the SIMS method found that reducing the input power or increasing the amount of oxygen impurities in the film forming gas during magnetic recording film formation increases the amount of oxygen incorporated into the film. . In this way, when the oxygen concentration in the magnetic film is high on the medium surface side, the lubricant adhesion is better than when the magnetic film is formed under the same conditions for comparison, and the lubricant is adhered more than 50 times. It exhibited high C8S strength properties.

Example 6 The magnetic disks of Examples 1 to 5 above were incorporated into a 2.4.8 disk magnetic disk device, and the average device life until an error occurred was determined. The lifespan was 2 to 10 times longer, and high device reliability was achieved.

〔Effect of the invention〕

As described above, according to the present invention, the lubricant can be retained not only on the medium surface but also inside the protective film, magnetic recording film, and underlayer, and the coverage of the lubricant on the surface is also high. We were able to provide a magnetic recording medium and device for high-density recording with excellent durability and corrosion resistance.

[Brief explanation of the drawing]

Fig. 1 is a partial cross-sectional view of a magnetic recording medium according to an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the distribution of fluorine atoms in the depth direction of the magnetic recording medium of Fig. 1, and Fig. 3 is a heating time. FIG. 4 is a diagram showing the relationship between oxygen gas concentration in N2 gas and coverage rate for explaining the present invention, and FIG. 5 is a diagram showing the relationship between FTIR absorbance and FTIR absorbance for explaining the present invention. C8S
FIG. 6 is a diagram showing the relationship between the strength and the relationship between the number of sliding movements and the tangential force for explaining the present invention. 1...Substrate 2.2'...Nonmagnetic plating layer 3.3'...Underlayer 4.4'...Magnetic recording film 5.5'...Protective film Attorney Nakamura Junnosuke trend 7' is distorted part μ sail] Figure 2 Seika (*f) CSS strength (K times)

Claims (1)

[Claims] 1. A magnetic recording medium having a magnetic recording film made of a metal magnetic alloy formed directly or via an underlayer on a substrate, and a protective film formed on the magnetic recording film. . A magnetic recording medium, wherein the magnetic recording film and the protective film contain a lubricant therein, and a thin layer of the lubricant is provided on the protective film. 2. The magnetic recording medium according to claim 1, wherein the magnetic recording medium has an underlayer, and the underlayer contains the lubricant therein. 3. The magnetic recording medium according to claim 1, wherein the lubricant is a compound in which the terminal group is nonpolar and has a substituent that is adsorbable to the protective film, the magnetic recording film, or both. 4. The magnetic recording medium according to claim 1, wherein the protective film is coated with the lubricant after being subjected to plasma treatment with a gas containing at least oxygen. 5. A magnetic recording film made of a metal magnetic alloy formed directly or via an underlayer on a substrate, and a protective film formed on the magnetic recording film, the magnetic recording film and the protective film having It has at least a magnetic recording medium containing a lubricant therein and a thin layer of the lubricant on the protective film, a magnetic head, a means for driving the magnetic head or the magnetic recording medium, or both, and a recording/reproducing circuit. A magnetic recording device characterized by: