JP2009245484A - Vertical magnetic recording medium and manufacturing method of same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertical magnetic recording medium wherein crystal grains of an underlayer and a magnetic layer are made fine without deteriorating crystal orientation and decreasing density of crystal grains. <P>SOLUTION: The vertical magnetic recording medium 10 includes a soft magnetic layer 13, an orientation control layer 14, the underlayer 15 and a main recording layer 17 on a disk substrate 11. The orientation control layer 14 contains, as a main material, an alloy formed by adding an oxide to at least one selected from NiW, NiPd, NiCr, NiMo, NiTa, NiV, NiNb, NiZr, NiHf and NiCu and thereby crystal grains of the underlayer 15 and the main recording layer 17 growing on the orientation control layer 14 are made fine. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a perpendicular recording medium mounted on a perpendicular magnetic recording type HDD (hard disk drive) or the like and a method of manufacturing the perpendicular magnetic recording medium.

  Various information recording techniques have been developed with the recent increase in information processing capacity. In particular, the surface recording density of HDD (Hard Disk Drive) using magnetic recording technology continues to increase at an annual rate of about 100%.

  In order to achieve a high recording density in a magnetic disk used for an HDD or the like, it is necessary to refine the magnetic crystal grains constituting the magnetic recording layer for recording information signals and reduce the layer thickness. It was. However, in the case of magnetic disks of the in-plane magnetic recording method (also called longitudinal magnetic recording method or horizontal magnetic recording method) that have been commercialized conventionally, the recording signal is caused by superparamagnetic phenomenon as a result of the progress of miniaturization of magnetic crystal grains. As a result, the so-called thermal fluctuation phenomenon occurs in which the recording signal disappears, which is an impediment to increasing the recording density of the magnetic disk. In order to solve this obstacle, a perpendicular magnetic recording type magnetic disk has been proposed.

  In the case of the perpendicular magnetic recording system, unlike the in-plane magnetic recording system, it is adjusted so as to be oriented in the direction perpendicular to the easy axis base surface of the main recording layer. The perpendicular magnetic recording method can suppress the thermal fluctuation phenomenon as compared with the in-plane recording method. In addition, a soft magnetic layer is provided on the perpendicular magnetic recording medium, the magnetic flux from the recording head is converged by the soft magnetic layer, and a sharper and larger magnetic field than the longitudinal recording medium can be generated by the mirror image effect. This is suitable for increasing the recording density.

  In the perpendicular magnetic recording system, when the magnetic recording layer has an hcp structure (hexagonal close-packed structure), the easy magnetization axis is the C axis, and it is necessary to orient the C axis in the normal direction of the substrate. In order to improve the orientation of the C axis, it is effective to provide a nonmagnetic underlayer having an hcp structure under the magnetic recording layer. CoCr alloys, Ti, V, Zr, Hf, and the like are known as materials for forming the underlayer. In particular, Ru (ruthenium) effectively improves the crystal orientation of the magnetic recording layer and increases the coercive force Hc. It is known that it can be.

  In the perpendicular magnetic recording system, in order to improve the S / N ratio (Signal / Noise Ratio) and the coercive force Hc, a non-magnetic substance or an oxide (for example, a patent document) is provided between magnetic grains (magnetic grains) of a magnetic recording layer. 1) is segregated to form a granular structure in which the grain boundary portion is formed, and the magnetic grains are isolated and refined. Furthermore, in order to promote the refinement of magnetic grains, it is important to refine the underlayer formed under the magnetic layer, and nonmagnetic substances or oxides are also added to the underlayer ( For example, see Patent Document 2).

JP 2003-036525 A JP 2006-085742 A

  Recently, there has been a demand for higher information recording density of magnetic disks, and an information recording capacity exceeding 160 GB per disk is required as a 2.5-inch diameter magnetic disk used for HDDs and the like. It is becoming. In order to meet such a demand, it is necessary to realize an information recording density exceeding 250 GB bits per square inch. In order to enable such a high recording density, it is necessary to further refine the magnetic grains and improve the S / N ratio (Signal / Noise Ratio). It is known to increase the amount of oxide added to the magnetic recording layer in order to reduce the size of magnetic grains in the conventional method. However, when the amount of oxide added increases, the oxide segregates to the grain boundary, the interval between the magnetic grains increases, and the density of the magnetic grains in the magnetic recording layer decreases. When the information recording density is increased, the bit area to be recorded becomes smaller, and a certain number of magnetic grains are required to ensure signal output. There is a limit to the refinement of grains.

  As another method for refining magnetic grains, it is known that an oxide can be added to the underlayer and the underlayer can be miniaturized. However, in this method, the addition of an oxide deteriorates the crystal orientation of the underlayer and may deteriorate the crystal orientation of the magnetic layer, which makes it difficult to control.

  The present invention has been made in view of such points, and by miniaturizing the orientation control layer laminated under the underlayer, the crystal orientation is not deteriorated and the density of the crystal grains is not lowered. It is an object of the present invention to provide a perpendicular magnetic recording medium capable of miniaturizing crystal grains of an underlayer and a magnetic layer laminated thereon, and a manufacturing method thereof.

  As a result of intensive studies by the inventors, by adding an oxide to the orientation control layer, the crystal grains of the orientation control layer, the underlayer grown on the orientation control layer, and the magnetic recording layer can be refined, and the S / N ratio is increased. It was found that can be improved. Then, the present inventors have completed the present invention by examining the materials of the respective oxides and further research.

  The orientation control layer is preferably formed of at least one substance selected from the group consisting of alloys of NiW, NiPd, NiCr, NiMo, NiTa, NiV, NiNb, NiZr, NiHf, and NiCu.

Examples of the oxide added to the orientation control layer include SiO ₂ , SiO, TiO ₂ , TiO, Cr ₂ O ₃ , Zr ₂ O ₃ , Ta ₂ O ₅ , Al ₂ O ₃ , W ₂ O ₅ , and Mo ₂ O _5. , V ₂ O ₅ , and Nb ₂ O ₅ are preferably formed from one substance selected from the group consisting of materials.

  The thickness of the orientation control layer is 1 nm or more, preferably 3 nm or more and 20 nm or less. When the orientation control layer has a thickness of 1 nm or less, it is difficult to control the crystal orientation of the initial layer, and thus the crystal orientation of the underlayer cannot be controlled. On the other hand, when the orientation control layer is 20 nm or more, the distance between the write head and the soft magnetic layer increases, and the write magnetic field becomes weak.

  According to the perpendicular magnetic recording medium and the manufacturing method of the perpendicular magnetic recording medium of the present invention, the size of the magnetic grains can be increased without reducing the magnetic grain density in the magnetic layer by using an oxide-added material as the orientation control layer. The thickness can be miniaturized. In addition, the magnetic layer can be stacked with almost no deterioration in the crystal orientation of the magnetic grains, and the recording / reproducing characteristics of the perpendicular recording medium can be improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing the structure of a perpendicular magnetic recording medium 10 according to this embodiment. This perpendicular magnetic recording medium 10 is a magnetic recording medium used in a perpendicular magnetic recording / reproducing system.

  A perpendicular magnetic recording medium 10 shown in FIG. 1 includes a disk substrate 11, an adhesive layer 12, a first soft magnetic layer 13a, a nonmagnetic spacer layer 13b, a second soft magnetic layer 13c, an orientation control layer 14, and a first underlayer 15a. The second underlayer 15b, the first onset layer 16a, the second onset layer 16b, the main recording layer 17, the continuous layer (continuous layer) 18, the medium protective layer 19, and the lubricating layer 20 are laminated in that order. Has been. The first soft magnetic layer 13a, the nonmagnetic spacer layer 13b, and the second soft magnetic layer 13c together constitute the soft magnetic layer 13. The first underlayer 15a and the second underlayer 15b together form the underlayer 15. The first onset layer 16 a and the second onset layer 16 b together constitute the onset layer 16.

  As the disk substrate 11, for example, a glass substrate, an aluminum substrate, a silicon substrate, a plastic substrate, or the like can be used. When a glass substrate is used for the disk substrate 10, for example, an amorphous aluminosilicate glass is formed into a disk shape by direct pressing to produce a glass disk, and this glass disk is subjected to grinding, polishing, and chemical strengthening sequentially. Can be produced. Since the aluminosilicate glass is smooth and has high rigidity, the magnetic spacing, particularly the flying height of the magnetic head, can be more stably reduced. Aluminosilicate glass can obtain high rigidity and strength by chemical strengthening.

  The adhesion layer 12 is a layer for improving the adhesion with the disk substrate 10 and can prevent the soft magnetic layer 13 from peeling off. As a material of the adhesion layer 12, for example, a Ti-containing material may be used. From the viewpoint of practical use, the thickness of the adhesion layer 12 is preferably 1 nm to 50 nm.

  As the first soft magnetic layer 13a and the second soft magnetic layer 13c of the soft magnetic layer 13, for example, an FeCoTaZr film or the like can be used. Examples of the composition of the nonmagnetic spacer layer 13b include a Ru film made of a nonmagnetic material. A nonmagnetic spacer layer 13b is interposed between the first soft magnetic layer 13a and the second soft magnetic layer 13c so as to have AFC (Antiferro-magnetic exchange coupling). As a result, the magnetization direction of the soft magnetic layer 13 can be aligned along the magnetic path (magnetic circuit) with high accuracy, and noise generated from the soft magnetic layer 13 can be reduced by extremely reducing the perpendicular component of magnetization. it can.

The orientation control layer 14 has an effect of protecting the soft magnetic layer 13, an effect of promoting alignment of crystal grains of the underlayer 15, and an action of refining crystal grains. In the present embodiment, the orientation control layer 14 includes Ni as a main material and an oxide material. The material of the orientation control layer 14 is preferably selected from alloys of NiW, NiPd, NiCr, NiMo, NiTa, NiV, NiNb, NiZr, NiHf, and NiCu having an fcc structure mainly composed of Ni. The oxide materials added to the orientation control layer 14 are SiO ₂ , SiO, TiO ₂ , TiO, Cr ₂ O ₃ , Zr ₂ O ₃ , Ta ₂ O ₅ , Al ₂ O ₃ , W ₂ O ₅ , It is preferably one selected from Mo ₂ O ₅ , V ₂ O ₅ and Nb ₂ O ₅ . As described above, by adding the oxide material to the orientation control layer 14, the effect of refining crystal grains is particularly increased.

  The material constituting the underlayer 15 has an hcp structure, and crystals of the hcp structure of the material constituting the main recording layer 17 can be grown as a granular structure. Accordingly, the higher the crystal orientation of the underlayer 15 is, the more the orientation of the main recording layer 17 can be improved. In addition to Ru, examples of the material for the underlayer 15 include RuCr and RuCo. Ru has an hcp structure and can satisfactorily orient the main recording layer containing Co as a main component.

  The underlayer 15 is composed of a Ru film having a two-layer structure. When forming the second base layer 15b on the upper layer side, the Ar gas pressure is set higher than when forming the first base layer 15a on the lower layer side. When the gas pressure is increased, the free movement distance of the plasma ions to be sputtered is shortened, so that the film formation rate is reduced and the crystal orientation can be improved. Further, by increasing the pressure, the size of the crystal lattice is reduced. Since the size of the Ru crystal lattice is larger than that of the Co crystal lattice, if the Ru crystal lattice is made smaller, it approaches that of Co, and the crystal orientation of the Co granular layer can be further improved.

By forming a nonmagnetic granular layer on the hcp crystal structure of the underlayer 15 and growing the granular layer of the main recording layer 17 thereon, the magnetic granular layer is separated from the initial stage (rise). Have. The compositions of the first onset layer 16a and the second onset layer 16b were nonmagnetic CoCr—SiO 2 and magnetic CoCrPt—Cr ₂ O ₃ .

The main recording layer 17 is a magnetic layer having an hcp crystal structure. Examples of the main recording layer 17 include CoCrPt—Cr ₂ O ₃ , CoCrPt—SiO ₂ , and CoCrPt—TiO ₂ . An hcp crystal structure is formed using a hard magnetic target made of CoCrPt containing silicon oxide (SiO 2) or titanium oxide (TiO 2) as a nonmagnetic substance. The main recording layer 17 can be appropriately set within a range of 7 nm to 15 nm. The composition of the target for forming the main recording layer 17 is composed of CoCrPt and SiO2 (or TiO2) at about 9: 1 (mol%). Nonmagnetic substances segregated around the magnetic substance to form grain boundaries, and the magnetic grains (magnetic grains) formed columnar granular structures. The magnetic grains were epitaxially grown continuously from the granular structure of the onset layer 16.

  The continuous layer 18 is made of a CoCrPtB film whose magnetism is continuous in the plane direction. The continuous layer 18 is formed of a low Ar gas, and the film thickness is preferably 10 nm or less, and desirably 5 nm or less.

  From the adhesion layer 12 to the continuous layer 18, film formation is sequentially performed on the disk substrate 11 by a DC magnetron sputtering method in an Ar atmosphere using a vacuum film forming apparatus. In consideration of productivity, it is preferable to form these layers and films by in-line film formation.

  The medium protective layer 19 is a protective layer for protecting the main recording layer 17 from the impact of the magnetic head. Examples of the material constituting the medium protective layer 19 include Cr, Cr alloy, carbon, zirconia, and silica. For example, carbon is formed by a CVD method while maintaining a vacuum. In general, since the film hardness of carbon formed by the CVD method is improved as compared with that formed by the sputtering method, the perpendicular magnetic recording layer can be more effectively protected against the impact from the magnetic head.

  The lubricating layer 20 is prepared by, for example, diluting perfluoropolyether (PFPE), which is a liquid lubricant, with a solvent such as Freon, and applying it to the surface of the medium by a dip coating method, a spin coating method, or a spray method, and heating if necessary Form by processing. The film thickness of the lubricating layer 20 is about 1 nm. This perfluoropolyether has a straight-chain structure, exhibits moderate lubrication performance for magnetic disks, and exhibits high adhesion performance to the carbon medium protective layer by having a hydroxyl group (OH) at the end group. can do.

  Next, Examples 1 to 7 in which the material of the orientation control layer 14 is changed with the same structure as that of the perpendicular magnetic recording medium 10 shown in FIG. 1, and a comparison in which the materials of the orientation control layer 14 and the underlayer 15 are changed. Examples 1 to 3 will be described.

Example 1
Amorphous aluminosilicate glass was molded into a disk shape with a direct press to create a glass disk. The glass disk was subjected to grinding, polishing, and chemical strengthening in order to obtain a smooth nonmagnetic disk substrate 11 made of a chemically strengthened glass disk. The disk substrate 11 was a 2.5-inch magnetic disk substrate having a diameter of 65 mm, an inner diameter of 20 mm, and a disk thickness of 0.635 mm. When the surface roughness of the obtained disk substrate 11 was observed with an AFM (atomic force microscope), it was confirmed that the surface was smooth with Rmax of 2.18 nm and Ra of 0.18 nm. Rmax and Ra are in accordance with Japanese Industrial Standard (JIS).

  Next, the adhesion layer 12, the soft magnetic layer 13, the orientation control layer 14, the underlayer 15, and the first onset are sequentially formed on the disk substrate 110 by DC magnetron sputtering using a C3040 sputtering film forming apparatus manufactured by Canon Anelva. The layer 16a, the second onset layer 16b, and the main recording layer 17 were formed.

  First, a film was formed using a CrTi target such that the adhesion layer 112 was a 10 nm CrTi45 (Cr: 55 at%, Ti: 45 at%) layer.

  Next, the FeCoTaZr target is formed so that the first and second soft magnetic layers 13a and 13c become 25 nm amorphous FeCoTaZr (Fe: 37 at%, Co: 55 at%, Ta: 3 at%, Zr: 5 at%) layer. Used to form a film. As the nonmagnetic spacer layer 13b, a Ru layer of 0.5 nm was formed using a Ru target.

Next, an orientation control layer 14 to be a 10 nm NiW—TiO ₂ (Ni: 86 at%, W: 8 at%, TiO ₂ : 6 at%) film was formed on the soft magnetic layer 13.

  Next, a first underlayer 15a made of Ru having a film thickness of 10 nm is formed on the orientation control layer 14 at a film forming gas pressure of 1.5 Pa, and further a film thickness of 10 nm is formed at a film forming gas pressure of 6.0 Pa. A second underlayer 15b made of Ru was formed.

Next, a first onset layer 16a made of a 1.0 nm CoCr—SiO ₂ (Co: 53 at%, Cr: 35 at%, SiO ₂ : 12 at%) film is formed on the underlayer 15, and A second onset layer 16b made of a 3 nm CoCrPt—Cr ₂ O ₃ (Co: 67 at%, Cr: 11 at%, Pt: 17 at%, Cr ₂ O ₃ : 5 at%) film was formed.

Next, a hard layer made of CoCrPt—TiO ₂ (Co: 64 at%, Cr: 11.5 at%, Pt: 14.5 at%, TiO ₂ : 10 at%) having an hcp crystal structure on the onset layer 16 is used. The main recording layer 17 was formed using a magnetic target. Furthermore, the continuous layer 18 was formed using a target of 7.5 nm CoCrPtB (Co: 60 at%, Cr: 20 at%, Pt: 15 at%, B: 5 at%).

  Next, a medium protective layer 19 made of hydrogenated carbon was formed by a CVD method. By using hydrogenated carbon, the film hardness is improved, so that the perpendicular main recording layer can be protected against an impact from the magnetic head.

  Thereafter, a lubricating layer 20 made of PFPE (perfluoropolyether) was formed by a dip coating method. The film thickness of the lubricating layer 20 is 1 nm.

  The recording / reproducing characteristics of the media obtained through the above steps were evaluated. The recording density was measured at 1200 kfci using an R / W analyzer and a magnetic head for perpendicular magnetic recording system having an SPT element on the recording side and a GMR element on the reproducing side. At this time, the flying height of the magnetic head was 10 nm.

(Comparative Example 1)
With the same film configuration as in Example 1 described above, the orientation control layer 14 was NiW (Ni: 92 at%, W: 8 at%).

(Comparative Example 2)
With the same film configuration as in Example 1 described above, Ru—SiO ₂ (Ru: 95 at%, SiO ₂ : 5 at%) was used as the first under layer 15a and the second under layer 15b.

(Comparative Example 3)
With the same film configuration as in Example 1 described above, the orientation control layer 14 is made of NiW (Ni: 92 at%, W: 8 at%), and the second underlayer 15 b is made of Ru—SiO ₂ (Ru: 95 at%, SiO2: 5 at%)

(Example 2)
In the same film configuration as in Example 1 described above, the orientation control layer 14 was NiW—TiO ₂ (Ni: 89 at%, W: 8 at%, TiO ₂ : 3 at%).

(Example 3)
In the same film configuration as in Example 1 described above, the orientation control layer 14 was NiW—SiO ₂ (Ni: 87 at%, W: 8 at%, SiO ₂ : 5 at%).

Example 4
In the same film configuration as in Example 1 described above, the orientation control layer 14 was NiW—Cr ₂ O ₃ (Ni: 82 at%, W: 7 at%, Cr ₂ O ₃ : 11 at%).

(Example 5)
With the same film configuration as in Example 1 described above, the orientation control layer 14 was NiW—Ta ₂ O ₅ (Ni: 62 at%, W: 5 at%, Ta ₂ O ₅ : 33 at%).

(Example 6)
The orientation control layer 14 was made of NiW—Nb ₂ O ₅ (Ni: 74 at%, W: 6 at%, Nb ₂ O ₅ : 20 at%) with the same film configuration as in Example 1 described above.

(Example 7)
In the same film configuration as in Example 1 described above, the orientation control layer 14 was NiW—Al ₂ O ₃ (Ni: 85 at%, W: 7 at%, Al ₂ O ₃ : 8 at%).

(Example 8)
The orientation control layer 14 was made of NiPd—TiO ₂ (Ni: 86 at%, Pd: 8 at%, TiO ₂ : 6 at%) with the same film configuration as in Example 1 described above.

Example 9
In the same film configuration as in Example 1 described above, the orientation control layer 14 was NiCr—TiO ₂ (Ni: 86 at%, Cr: 8 at%, TiO ₂ : 6 at%).

(Example 10)
In the same film configuration as in Example 1 described above, the orientation control layer 14 was NiMo—TiO ₂ (Ni: 86 at%, Mo: 8 at%, TiO ₂ : 6 at%).

Example 11
With the same film configuration as in Example 1 described above, the orientation control layer 14 was NiTa—TiO ₂ (Ni: 86 at%, Ta: 8 at%, TiO ₂ : 6 at%).

Example 12
With the same film configuration as in Example 1 described above, the orientation control layer 14 was NiV-TiO ₂ (Ni: 86 at%, V: 8 at%, TiO ₂ : 6 at%).

(Example 13)
In the same film configuration as in Example 1 described above, the orientation control layer 14 was NiNb—TiO ₂ (Ni: 86 at%, Nb: 8 at%, TiO ₂ : 6 at%).

(Example 14)
In the same film configuration as in Example 1 described above, the orientation control layer 14 was NiZr—TiO ₂ (Ni: 86 at%, Zr: 8 at%, TiO ₂ : 6 at%).

(Example 15)
In the same film configuration as in Example 1 described above, the orientation control layer 14 was NiHf—TiO ₂ (Ni: 86 at%, Hf: 8 at%, TiO ₂ : 6 at%).

(Example 16)
In the film configuration similar to that of Example 1 described above, the orientation control layer 14 was NiCu—TiO ₂ (Ni: 86 at%, Cu: 8 at%, TiO ₂ : 6 at%).
As the magnetic recording medium 10 according to the example, the magnetic recording medium 10 having the configuration described with reference to FIG. 1 is manufactured. In the manufacturing process of the magnetic recording medium 10, the layers formed on the disk substrate 11 are sequentially formed by, for example, a soft magnetic layer forming process, a magnetic recording layer forming process, and the like. In addition, in the process of forming each layer, you may be the same or the same process as each well-known process except a soft magnetic layer formation process.

FIG. 2 shows the average grain size of the magnetic recording media prepared in Examples 1 to 16 and Comparative Examples 1 to 3 evaluated from a plane photograph of a transmission electron microscope, Δθ ₅₀ evaluated with an X-ray diffractometer, and recording / reproduction. The evaluation result of characteristic S / N is shown. The area of each crystal grain obtained from a plane photograph of a transmission electron microscope is converted to a circle, and the radius of the circle is defined as the crystal grain size. The average crystal grain size is an average value obtained from several hundred crystal grains. Δθ ₅₀ indicates the half-value width of the roking curve of the Ru (002) crystal orientation peak.

  2, Examples 1 to 7 in which an oxide is added only to the orientation control layer 14 without adding an oxide to the underlayer 15 can reduce the magnetic particle size of the magnetic layer and oxidize the underlayer. It can be confirmed that the deterioration of the crystal orientation of the magnetic grains is suppressed as compared with Comparative Examples 2 and 3 to which the product is added.

  The layer configuration, the material, the number, the size, the processing procedure, and the like in the above embodiment are merely examples, and various modifications can be made within the range where the effects of the present invention are exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

Cross-sectional configuration diagram of a magnetic recording medium according to an embodiment The figure which shows the evaluation result of Examples 1-16 and Comparative Examples 1-3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Magnetic recording medium 11 Disk base body 12 Adhesion layer 13 Soft magnetic layer 13a First soft magnetic layer 13b Nonmagnetic spacer layer 13c Second soft magnetic layer 14 Orientation control layer 15 Underlayer 15a First underlayer 15b Second underlayer 16 On Set layer 16a First onset layer 16b Second onset layer 17 Main recording layer 18 Continuous layer 19 Medium protective layer 20 Lubricating layer

Claims (7)

A non-magnetic substrate;
A soft magnetic layer formed on the non-magnetic substrate;
An orientation control layer formed on the soft magnetic layer, mainly made of Ni and added with an oxide;
A nonmagnetic underlayer having a hexagonal close-packed structure formed on the orientation control layer;
A magnetic recording layer formed on the nonmagnetic underlayer and having a hexagonal close packed crystal grown as a granular structure;
A perpendicular magnetic recording medium comprising:   The orientation control layer is mainly composed of an alloy obtained by adding an oxide to at least one selected from NiW, NiPd, NiCr, NiMo, NiTa, NiV, NiNb, NiZr, NiHf, and NiCu. The perpendicular magnetic recording medium according to claim 1. The orientation control _{layer, SiO 2, SiO, TiO 2} , TiO, Cr 2 O 3, Zr 2 O 3, Ta 2 O 5, Al 2 O 3, W 2 O 5, Mo 2 O 5 as the oxides, 3. The perpendicular magnetic recording medium according to claim 1, wherein at least one material selected from V ₂ O ₅ and Nb ₂ O ₅ is added.   The perpendicular magnetic recording medium according to any one of claims 1 to 3, wherein the orientation control layer has a thickness of 1 nm to 20 nm.   The perpendicular magnetic recording medium according to claim 1, wherein the underlayer includes Ru or a Ru alloy.   6. The perpendicular magnetic recording medium according to claim 1, wherein the magnetic recording layer is made of CoCrPt-oxide. Forming a soft magnetic layer on the substrate; forming an orientation control layer in which an oxide is added to a material mainly composed of Ni on the soft magnetic layer; and a hexagonal close packed structure on the orientation control layer And forming a magnetic recording layer by growing a hexagonal close packed crystal as a granular structure on the nonmagnetic underlayer. A method for manufacturing a recording medium.

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