JP2515771B2 - Magnetic recording media - Google Patents

Description

The present invention relates to a magnetic recording medium for a magnetic disk device or the like, and is particularly suitable for high recording density and has excellent reliability such as corrosion resistance and sliding resistance. Regarding the medium.

[Conventional technology]

Conventionally, as a magnetic recording medium for high recording density,
A medium using a metal magnetic thin film has been proposed as disclosed in Japanese Patent No. 33523. Generally, the medium forming method includes a vapor deposition method, a sputtering method, a plating method, an ion beam sputtering method, and the like. Recently, demands for higher recording density and higher reliability have been increasing, and in order to improve corrosion resistance in particular, JP-A-57-15406 and JP-A-57-196 have been proposed.
As disclosed in Japanese Patent No. 508, it has been proposed to add a third element such as Cr and Nb to a magnetic metal.

[Problems to be solved by the invention]

However, these inventions are mostly related to magnetic recording tapes, and have not yet met the stricter specifications regarding reliability, such as hard disks for computers.

An object of the present invention is to provide a magnetic recording medium comprising a Co—Ni based magnetic metal thin film having improved corrosion resistance while substantially maintaining the excellent magnetic properties of the metal magnetic thin film.

[Means for solving problems]

Periodic table Ib, IIIa, IVa, Va, VIII group 4th, 5th, 6th
As a result of diligent examination of the magnetic characteristics and corrosion resistance of the magnetic film formed by sputtering, etc., by adding a periodic element to Co-Ni, in order to achieve the above objective, Zr It has been found that inclusion in an alloy thin film is extremely effective. The magnetic recording medium of the present invention is based on such knowledge, and the above-mentioned object is mainly achieved by using C on a non-magnetic substrate.
It consists of o, Ni, Zr, and the content of Zr is relative to Co and Ni.
0.1 at% or more and 30 at% or less, more preferably Ni content of 10 at% or more with respect to Co in order to improve magnetic properties.
60 at% or less, and more preferably, the content of Ni is Co
To 20 at% or more, 50 at% or less, more preferably 30 at% or more and 48 at% or less, and the content of Zr is Co
2 at% or more and 20 at% or less with respect to Ni, desirably 2 at% or more
15 at% or less, more preferably 3 at% or more and 12 at% or less,
More preferably, it is achieved by forming a magnetic layer of 4 at% or more and 11 at% or less. Further, a Cr intermediate layer of 100 Å or more and 5000 Å or less is formed between the magnetic layer and the non-magnetic substrate, or in the case of a medium using a metallic substrate, its surface is oxidized by 10 to 400 Å and directly or on it. By forming the magnetic layer via the Cr layer, it is possible to provide a medium having excellent recording and reproducing characteristics. On the other hand, 20Å on the substrate surface
As described above, by interposing at least one of the Si, C, and Ge intermediate layers having a thickness of 1000 Å or less, it is possible to provide a medium particularly excellent for perpendicular magnetic recording. By forming a 100 Å to 1000 Å non-magnetic coating film on the surface of the above medium, it is possible to provide a medium having further improved corrosion resistance and excellent sliding resistance.

[Action]

The above invention has the following functions. 500 Å (Co _0.7 Ni _0.3 ) _0.9 Zr _0.1 formed on glass substrate by RF sputtering method at Ar pressure 5mTorr, input power 5W / cm ² , substrate temperature 150 ℃.
(Co _0.8 Ni _0.2 ) _0.8 Zr _0.2 , (Co _0.9 Ni _0.1 ) _0.7 Zr _0.3 ,
(Co _0.6 Ni _0.4 ) _0.95 Zr _0.05 Magnetic thin film by Auger spectroscopy,
As a result of analysis by the anodic polarization curve method, it was revealed that a dense oxide film with high Zr concentration was formed from the surface to a depth of 60 to 30 Å. Ninth
The figure shows the typical composition distribution of CoNiZr thin film in the film thickness direction. Here, the sample is an Ar pressure of 10 mTo on a Si substrate at 150 ° C.
rr, input electric power of 2 W / cm ² and forming a Cr underlayer of 5000 Å, and then continuously forming (Co _0.7 Ni _0.3 ) _0.95 Zr _0.05 with a film thickness of 500 Å
Is formed into a film. This profile was the same even when a non-magnetic coating layer such as C was provided on the magnetic film. Neither nitrogen nor oxygen was found in the magnetic film. That is, Zr
Is preferentially gathered on the surface of the magnetic thin film to form a dense passivation film, which significantly improves the corrosion resistance of the magnetic film. This effect was observed when the Zr concentration was 0.1 at% or more.
On the other hand, although the saturation magnetic flux density of the medium is lowered by the addition of Zr, if the Zr content is 30 at% or less with respect to Co and Ni,
The saturation magnetic flux density is equal to or higher than that of the oxide magnetic medium, and it has been clarified that there is no problem in practical use.

However, the CoNiZr alloy is disclosed in JP-A-56-44752 (USP4306
908) and iEeTransaction on Magnetics, MAG 16, (1980) No. 11
Pages 29 to 1131 (IEEE, Trans.on Magn. MAG-16 (198
0) pp1129-1131), it is easy to amorphize when created by the ultra-quenching method and the like, and has a low coercive force, which is suitable for magnetic head materials, but not preferable as magnetic recording medium materials. It has been known. On the other hand, C, after forming a body-centered cubic lattice metal such as Cr, Mo, W by sputtering, vapor deposition, ion beam sputtering, etc.
When the oNiZr magnetic film is formed, it is predominantly crystalline without heat treatment, and has a high coercive force of 500 Oe or more, and can have magnetic characteristics suitable as a magnetic recording medium. That is, at an Ar pressure of 5 mTorr and a substrate temperature of 180 ° C., on a glass substrate or an Al alloy substrate plated with NiP, a DC sputtering method was used to apply a power of 5 W / cm ² and a film thickness of 2500 Å.
After forming Cr, the film thickness of 600Å (Co _0.6 Ni _0.4 ) is continuously formed.
_1-x Zr _x (x; 0,0.02,0.03,0.08,0.11,0.12,0.125,0.15,0.
175, 0.225) When a magnetic film is formed, as shown in Fig. 10, when the Zr composition is small, it is crystalline and has a large coercive force of 500 Oe or more, but when the Zr composition exceeds 15 at%, it becomes amorphous rapidly. The quality is improved and the coercive force is reduced to 500 Oe or less. Here, if the Zr composition is more than 15 at% and 30 at% or less, heat treatment of the substrate at 280 ° C to 500 ° C is performed to produce CoNiZr.
Since the magnetic thin film can be crystallized to have a high coercive force, it can be used as a magnetic recording medium within this composition range. However, in general, amorphous NiP with a P composition of 10.5 wwt%
An Al alloy disc plated with 5 to 30 μm is used as a disc substrate. This is to improve the strength of the disc and to improve the surface flatness and the floating property. Here, when the substrate is heat-treated at 250 ° C. to 300 ° C. for about 3 hours,
The above-mentioned heat treatment of the substrate is not very preferable because it is crystallized and magnetized. Further, such a heat treatment is preferably performed immediately before forming the protective film in order to suppress the reaction, and there is a drawback that the process becomes complicated. Therefore, in order to obtain a high coercive force of 500 Oe without heat treatment, it is desirable from FIG. 10 that the Zr composition is 15 at% or less. Zr in terms of improving corrosion resistance
The composition is preferably 2 at% or more. From the viewpoint of improving the coercive force by adding Zr, from FIG. 10, it is more desirable that the Zr composition is 3 at% or more and 12 at% or less, and more desirably 4 at% or less.
It is preferable to be at% or more and 11 at% or less. However, in order to improve the recording / playback characteristics such as overwrite,
It is necessary to thin the magnetic medium, and for this purpose
It was also clarified that the Ni content is preferably 60 at% or less with respect to Co. On the other hand, in order to improve the recording density of the medium, it is necessary to increase the coercive force of the medium. To this end, as shown in FIG.
Greater than at% and less than or equal to 50 at%, more preferably 30 at
% Or more and 48 at% or less, it is desirable to interpose Cr, a surface oxide layer or Si, C, Ge as a magnetic property control layer of a magnetic film for in-plane or perpendicular magnetic recording depending on the purpose. Considering magnetic properties such as coercive force and economical efficiency, the Cr film thickness is 100 Å or more and 5000 Å or less, and the oxide layer film thickness is 10 Å or more 400
Å or less, Si, C, Ge film thickness is preferably 20 Å or more and 1000 Å or less. Furthermore, by forming a 100-liter or more non-magnetic coating film on the surface of the magnetic layer, it is possible to improve the sliding resistance and the corrosion resistance. However, when the film thickness is thicker than 1000Å, spacing loss increases, which is not preferable in terms of recording / reproducing characteristics.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 11
Is a substrate made of Al alloy, 12 and 12 'are Ni-P, Ni-W-
A non-magnetic plating layer made of P, 13 and 13 'are magnetic control layers made of Cr, and 14 and 14' are magnetic layers made of Co-Ni-Zr alloy. .

Outer diameter 130mmφ, inner diameter 40mmφ, thickness 1.9mm Al alloy substrate 11
A non-magnetic 12 wt% P-Ni plating layer 12, 12 'having a thickness of 20 .mu.m was formed on the above. On this substrate, substrate temperature 180 ℃, Ar pressure 5mTor
r, RF input power of 4 W / cm ² was used to form Cr thin film 13, 13 ′ with 2500 Å, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Ru, Rh, Pd, Pt was 0.0
5at%, 0.1at%, 1at%, 10at%, 15at%, 20at%, 30at%, 40
The magnetic layers 14 and 14 'were formed to 600 Å using Co _0.7 Ni _0.8 alloy target containing at% and 50 at%. Fig. 2 shows 40 ℃, 1
A salt spray test using specified NaCl shows the time-dependent change of the saturation magnetic flux density of the magnetic disk when the relative concentration of the third additive element to CoNi is 10 at%. _Figure 21 shows the results of magnetic disks using Co _0.7 Ni _0.8 alloy thin films. Ti, Pt, Ru, T
By adding a, Rh, V, Nb, Cr, Zr, Pd, the corrosion resistance of CoNi is improved, but by adding Zr, Nb, the saturation magnetic flux density does not deteriorate and excellent corrosion resistance can be exhibited. Do you get it. This effect was substantially the same if the added amount was 0.1 at% or more.

Next, outer diameter 220mmφ, thickness 1.9mm Al alloy substrate 11,15μm
On a substrate using non-magnetic 11wt% P-Ni plating layers 12, 12 'at a substrate temperature of 150 ° C, an Ar pressure of 10mTorr, and a DC input power of 7W / cm ² .
A Cr film 13,13 ′ is formed on 1500 Å and Zr, Rh, Nb, Pd, W, V are formed under the same conditions.
Magnetic layers 14 and 14 'were formed to a thickness of 500 Å using a Co _0.75 Ni _0.25 alloy target containing 8 at% of. FIG. 3 shows the change over time in the saturation magnetic flux density when the disc was immersed in a 1N NaCl aqueous solution at 40 ° C. Especially when Zr was added, a remarkable improvement in corrosion resistance was observed. At this time, all the magnetic films were predominantly polycrystalline. This effect is only required if Zr is the main additive, and excellent corrosion resistance is exhibited even if Ti, Pt, Ru, Ta, Rh, V, Nb, Cr, and Pd are also contained. That is (Co
_0.7 Ni _0.3 ) _0.95 Zr _0.05 , (Co _0.6 Ni _0.4 ) _0.94 Zr _0.06 (Co
_0.65 Ni _0.45 ) _0.95 Zr _0.05 with Ru 0.5,1.0 at%, Ta 1,2,5a
t%, Cr 1,2,5at%, Ti 1,2,4at%, Nb 2,4,6at%, Rh
0.2,0.5,1.0at%, Pt 0.2,0.5,1.0at%, Pd 0.2,0.5,1.
A magnetic film containing 0 at% and V at 2,4,6 at% was formed and its corrosion resistance was evaluated by a high temperature and high humidity test in a room at 60 ° C, 90% RH class 10,000. Addition of these fourth elements to all the magnetic films was particularly excellent in that the amount of decrease in magnetization after 2 weeks was 5% or less. This is because the addition of these fourth elements strengthens the structure of the surface oxide film and improves uniform corrosion and corrosion resistance to oxidation.
The above effects were recognized when the amount of the above elements added was 0.01 at% or more. However, if the amount added exceeds 15 at%, the saturation magnetization will decrease, which is not desirable.

Co _0.9 Ni _0.1 , Co _0.6 Ni _0.4 , Co _0.5 Ni _0.5 , Co _0.4 Ni _0.6 , Co
_When an alloy target in which Zr is added at 15 at% to _0.3 Ni _0.7 , Co _0.62 Ni _0.3 Cr _0.08 , and the Cr film thickness is 2000 Å and the magnetic layer is 700 Å, the same as the above two examples for Zr addition The effect was found, and a significant improvement in corrosion resistance was observed by adding Zr of 0.1 at% or more. But Zr 30
It has been found that when added in excess of at%, the saturation magnetic flux density and coercive force are significantly deteriorated, which is not desirable in practice, and the added amount is preferably 30 at% or less.

Fig. 4 shows the coercive force of the magnetic disk shown in Fig. 2. The coercive force and squareness ratio are 60 unless Pd is added.
It was 0 Oe or more and 0.8 or more, and all the disks except the Pd additive had excellent recording and reproducing characteristics. Fig. 5 shows a magnetic layer with a Z content of 12 at% for Co and Ni of 600Å and a film thickness of 1000.
The relation between the coercive force and the Ni content with respect to Co when formed by DC magnetron sputtering with Ar pressure of 7 mTorr and 8 W / cm ² on Cr of Å is shown. Ni content to Co is 10at% or more, 60at
%, An in-plane coercive force of about 550 Oe or more required for high recording density is obtained. If the Ni content is more than 20 at% and 50 at% or less, a higher recording density can be achieved. In fact, with a Mn-Zn ferrite head with a gap length of 0.4 μm, a high recording density of 20 KFCI or more was achieved when the flying height was 0.25 μm. In Fig. 5, if the content of Ni to Co is more than 20 at% and less than 50 at%, the coercive force is as high as 650 Oe or more, and the Ni content is more than 30 at% and 48 at.
% Or less, the coercive force is further increased to 750 Oe or more, which is more desirable in terms of recording / reproducing characteristics. In fact, the outer diameter is 130 mm
11.5wt% P-Ni on the φ11 and 1.9mmt thick Al alloy substrate 11
After plating μm and polishing the surface, a fine scratch of 60Å with center line average roughness Ra is further made on the surface in the circumferential direction of the substrate.
Substrate temperature 2 on the non-magnetic plating layer 12 and 12 'of 15μm
Film thickness 3000Å at 00 ℃, Ar gas pressure 15mTorr, input power 1W / cm ²
Magnetic control layers 13 and 13 'made of Cr are formed, and then (Co _1-x Ni _x ) _0.955 Zr _0.045 magnetic layer (x
= 0.2,0.25,0.3,0.37,0.40,0.45,0.48,0.50) 14,14 'is formed, then a non-magnetic film layer of C with a film thickness of 450 Å is formed at 3 mTorr, 8 W / cm ² and finally A 40 Å liquid lubricant made of perfluoroalkyl polyether was formed into a magnetic disk, and its recording / reproducing characteristics were evaluated with a thin film magnetic head with a gap length of 0.4 μm. As shown in FIG. Especially S / N when 30at% or more and 48at% or less
The ratio was high and the recording / reproducing characteristics were extremely good.

In the above examples, when the magnetic layer was formed directly on NiP, the coercive force was only about 50 Oe, and by forming the magnetic layer through the Cr film of 100 Å or more, the coercive force practically sufficient was obtained. However, even if Cr that is thicker than 5000Å is formed, the effect of improving the coercive force is the same as when Cr with a film thickness of less than this is used, and in terms of production efficiency, the Cr thickness is 5000Å or less, and more desirably
It is preferably 3000 Å or less.

5mTorr, 4W / cm ² , substrate temperature 10
After Ni-WP was deposited on an Al alloy substrate 11 having a thickness of 25 μm (12,12 ′) formed at 0 ° C., a (Co _0.6 Ni _0.4 ) _0.8 Zr _0.2 magnetic film (14,14 ′) was formed to a thickness of 0.2 μm. By doing so, a medium excellent in corrosion resistance and perpendicular magnetic recording characteristics could be formed. 20 as the middle layer
The same was true when 0Å Si and 50Å Ge were used. Moreover, the effect of the intermediate film was recognized for film thicknesses of 20 Å or more. However, for practical use, a film thickness of 1000Å or less was sufficient.

FIG. 6 shows an embodiment of a structure different from that of FIG. Substrate 61 made of Al alloy, non-magnetic plating layer 62, 62 ', Co-Ni
The magnetic layers 63 and 63 'are made of a -Zr alloy.

Nonmagnetic 11.5wt% on Al alloy substrate 61,15μm with outer diameter 90mmφ
Substrates with P-Ni plating layers 62 and 62 'are placed at a substrate temperature of 100 ° C and O
_By performing reverse sputtering in Ar gas containing 20% of ₂ (5 mTorr, 0.4 W / cm ² ), an oxide layer of 30 Å is formed, and then Ar pressure is applied.
5mTorr, 6W / cm ^2, comprising 5,15At% of Zr at a substrate temperature of 0.99 ° C. Co-N
The magnetic films 63 and 63 ′ were formed to 600 Å using an i alloy target. FIG. 7 shows the relationship between the saturation magnetic flux density of the magnetic film and the Ni content with respect to Co when the Zr content with respect to Co and Ni is 10 at%. Practically sufficient saturation magnetic flux density has been obtained for Ni of 50 at% or less. The coercive force was similar to that shown in FIG. 5, and excellent recording / reproducing characteristics were obtained as with the disk having the configuration shown in FIG. Although the corrosion resistance was slightly deteriorated as compared with the disk having the structure shown in FIG. 1, it was also found that there was no problem at a practical level. When the magnetic film was formed through the Cr layer as shown in FIG. 1 after the NiP surface was reverse-sputtered in this way to form an oxide, the best recording and reproducing characteristics were obtained.

In addition to the above examples, a magnetic disk was formed by forming a magnetic film in Ar gas containing O ₂ and setting the O content in the magnetic film to 0.1 to 15 at%. FIG. 12 shows a typical example of the composition distribution (Auge profile) in the film thickness direction of the magnetic disk according to the present invention in which (Co _0.7 Ni _0.3 ) _0.95 Zr _0.05 contains 7 at% oxygen. No other element such as nitrogen was found. Although there are drawbacks such as a decrease in saturation magnetic flux density and a slight deterioration in corrosion resistance, in this case as well, a medium having a practically no problem level could be formed. That is, 130 mmφ Al alloy substrate 1
After plating 11 wt% P-Ni on 1 and mirror-polishing, scratches of 70 Å with centerline average surface roughness in the same direction of the disk, and film thickness 10
The composition of the magnetic film is (Co _0.7 Ni _0.3 ) _0.95 Zr _0.05 , (Co _0.7 Ni _0.3 ) _0.94 Zr on the non-magnetic plating layers 12 and 12 ′ having a thickness of μm.
_0.06 , (Co _0.65 Ni _0.35 ) _0.94 Zr _0.06 , (Co _0.60 Ni _0.40 )
_0.94 Zr _0.06 (Co _0.7 Ni _0.3 ) _0.945 Zr _0.05 Ru _0.005 , (Co
_0.6 Ni _0.4 ) _0.91 Zr _0.05 Ta _0.04 , (Co _0.7 Ni _0.3 ) _0.9 Zr
_0.05 Mo _0.05 consisting of 0,2,5,7,10,15at% oxygen and magnetic layer 14,14 'with a film thickness of 600Å and Cr underlayer 13,13 with a film thickness of 2500Å. A protective film of C, B ₄ C, SiO _{2 with a} thickness of 400 Å and a liquid lubricant of perfluoroalkyl polyether on the surface of 50 Å to form a magnetic disk. When recording and reproducing were evaluated at a velocity of 13.5 m / s and a flying height of 0.22 μm, the output decreased with the oxygen content, but the noise further decreased and the media S / N ratio increased with the oxygen content.
This is because oxygen is preferentially bound to Zr, the interaction between crystal grains is reduced, and the magnetization transition region between recording bits becomes smaller with the amount of oxygen. If oxygen is contained at 15 at% or more, the output is remarkably decreased, and the total S / N is rather decreased considering the head medium system, which is not preferable.

On the magnetic disk of the present embodiment having the structure shown in FIGS. 1 and 6, Ar pressure of 5 mTorr, 8 W / cm ² and substrate temperature of 150 ° C.
The magnetic recording medium with a thin film formed by the 500ÅDC magnetron system showed a significant improvement in corrosion resistance by the corrosion resistance test method shown in Fig. 3 without any change in oxidation even after 8 hours. Became. Further, it has been revealed that the sliding resistance is improved by 1 to 5 digits or more as compared with the case where there is no C film, and that it is preferable to form the C film also in terms of reliability.
The above effect was confirmed when the thickness of the protective film was 100 Å or more, but when it was 1000 Å or more, it became clear that the recording density characteristic was remarkably deteriorated, which was not preferable in practical use. B, B
Similar effects were observed when N, SiC films were formed or when the surface of the magnetic film was thermally oxidized. By forming the organic lubricant, it was confirmed that the reliability was improved by 2 to 3 times.

FIG. 8 shows still another embodiment. 81 is an Al substrate whose surface is anodized, or an organic substrate such as polyimide or PET, 82 and 82 'are magnetic control layers similar to those shown in FIG. 1, and 83 and 83' are Co-Ni-Zr. Magnetic layer, consisting of 8
4,84 'is a non-magnetic coating layer similar to that described above.
The composition, film thickness, and film forming method are as described above.

In this embodiment, the magnetic disk and the floppy disk have been described as an example, but the present effect is not limited to these media and can be applied to a magnetic tape or the like. Further, the film forming method is not limited to the spattering method, but may be a vapor deposition method, an ion beam sputter method, or the like.

〔The invention's effect〕

As described above, according to the present invention, while substantially maintaining the excellent magnetic properties of the metal magnetic recording thin film, it has a Co-Ni-based metal magnetic thin film having significantly better corrosion resistance than the conventional medium. A magnetic recording medium can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a magnetic disk according to an embodiment of the present invention, FIGS. 2 and 3 are diagrams showing the results of a salt spray test and a salt water immersion test for the magnetic disk of the present invention, FIG. 4, FIG. FIG. 5 is a diagram showing their magnetic characteristics, FIG. 6 is a sectional view of a magnetic disk of another embodiment, and FIG. 7 is a diagram showing their magnetic characteristics.
FIG. 8 is a sectional view of a magnetic disk according to still another embodiment, and FIG. 9 is a diagram showing a composition distribution in the film thickness direction of a CoNiZr / Cr film.
Fig. 0 shows the in-plane coercive force of the magnetic disk of the present invention and the Zr of the magnetic film.
Figure showing the relationship with the content, FIG. 11 is a diagram showing the relationship between the S / N of the magnetic disk according to the present invention and the Ni content of the magnetic film,
FIG. 12 is a diagram showing the composition distribution in the film thickness direction of another example according to the present invention. 11, 61, 81 ... Substrate, 12, 12 ', 62, 62', ... Non-magnetic plating layer, 13, 13 ', 82, 82' ... Magnetic control layer, 14, 14 ', 63,
63 ', 83,83' ... magnetic layer, 84,84 '... non-magnetic coating layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norikazu Sekida 1-280 Higashi Koigakubo, Kokubunji City, Central Research Laboratory, Hitachi, Ltd. (72) Norio Suganuma 1-280 Higashi Koigakubo, Kokubunji City, Hitachi Research Institute, Ltd. (72) Inventor Yoshio Gohara 2880, Kozu, Odawara City, Odawara Plant, Hitachi, Ltd. (72) Inventor Shosho Hayashi, 2880, Kozu, Odawara City, Odawara Plant, Hitachi, Ltd. (56) Reference JP 61-224121 (JP, A) JP-A-56-44752 (JP, A) JP-A-61-294629 (JP, A)

Claims (11)

(57) [Claims] 1. A magnetic recording medium having a magnetic layer formed on a non-magnetic substrate, wherein the magnetic layer is mainly composed of Co, Ni and Zr, and the Zr content is 0.1 at% with respect to Co and Ni. More than 30at
% Or less is predominantly crystalline, and the total amount in the magnetic layer is 0.
A magnetic recording medium containing 1 at% or more and 15 at% or less of O. 2. The magnetic recording medium according to claim 1, wherein Zr is segregated on the surface of the magnetic layer in the magnetic recording medium having a magnetic layer formed on a non-magnetic substrate. 3. The content of Zr with respect to Co and Ni of the magnetic film is
The magnetic recording medium according to claim 1 or 2, wherein the content is 2 at% or more and 20 at% or less. 4. The content of Ni is 10 at% or more with respect to Co and 60.
The magnetic recording medium according to claim 1 or 2, which is at% or less. 5. The content of Ni is more than 20 at% and less than 50 at% with respect to Co, and the content of Zr is 2 at% with respect to Co and Ni.
% Or more and 20 at% or less, The magnetic recording medium according to claim 1 or 2, wherein 6. The magnetic film comprises Ti, Pt, Ru, T in addition to Co, Ni, Zr.
Claim 1 characterized in that at least one kind of a, Rh, V, Nb, Cr, Pd is contained in a total amount of 0.01 at% or more and 15 at% or less.
The magnetic recording medium according to any one of items 1 to 5. 7. The Cr intermediate layer of 100 Å or more and 5000 Å or less is interposed between the magnetic layer and the non-magnetic substrate, as claimed in any one of claims 1 to 6. Magnetic recording medium. 8. A non-magnetic metal substrate having a surface of 10 to 40.
The magnetic recording medium according to any one of claims 1 to 7, wherein 0Å is a substrate that is oxidized. 9. The magnetic layer is a perpendicular magnetic recording medium, and at least one layer of Si, C, or Ge intermediate layer of 20 Å or more and 1000 Å or less is interposed between the magnetic layer and the nonmagnetic substrate. The magnetic recording medium according to any one of claims 1 to 6, characterized in that: 10. A film thickness of 100 to 1000 on the surface of the magnetic layer.
The magnetic recording medium according to any one of claims 1 to 9, wherein a non-magnetic coating film of Å is formed. 11. The magnetic recording medium according to any one of claims 1 to 10, wherein the non-magnetic substrate is an Al alloy plated with either NiP or NiWP.