JP2006092715A - Perpendicular magnetic recording medium, its manufacturing method and magnetic recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic recording medium having an excellent error rate, easily manufactured without generating a WATE (Wide Area Track Erasure) problem, and making recording and reproducing information of high density, by forming a plurality of grooves along a substrate radial direction by texturing treatment on the surface of a non-magnetic substrate, and also to provide its manufacturing method, and a magnetic recording and reproducing device. <P>SOLUTION: In the perpendicular magnetic recording medium having at least a backing layer and a perpendicular magnetic recording film on the non-magnetic substrate, the plurality of grooves along the substrate radial direction are formed by the texturing treatment on the surface of the non-magnetic substrate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a perpendicular magnetic recording medium, a manufacturing method thereof, and a magnetic recording / reproducing apparatus including the magnetic recording medium and a magnetic head.

In recent years, the application range of magnetic recording devices such as magnetic disk devices, floppy (registered trademark) disk devices, magnetic tape devices and the like has been remarkably increased, and the importance has increased, and the recording of magnetic recording media used in these devices has been improved. The density has been significantly improved.
In particular, since the introduction of the MR head (magnetoresistance effect type head) and PRML (Partial Response Maximum Likelihood) technology, the increase in the surface recording density has increased further, and in recent years, the GMR head (giant magnetoresistance effect type head) has further increased. TMR heads (tunnel magnetoresistive heads) have also been introduced, and the number continues to increase at a rate of about 100% per year.

  For these magnetic recording media, it is required to achieve higher recording density in the future, and for that purpose, a higher coercive force of the magnetic recording layer, a higher signal-to-noise ratio (S / N ratio), and higher resolution are achieved. It is requested. In recent years, the absolute film thickness of the medium has been reduced in order to achieve a high surface recording density, and as a result, the phenomenon that the recording magnetization is weakened by thermal disturbance is becoming a problem. Thermal stability has become a major technical issue. In particular, there are many cases where the thermal stability is lowered when trying to improve the above-described SN ratio, and the coexistence of these two is a development target. This is because, in general, in a medium having an excellent SN ratio, the crystal grain size of the magnetic particles constituting the magnetic layer is often fine, which is effective for medium noise, but the thermal stability of magnetism. This is because it can be said that it is close to the unstable region from the viewpoint.

In recent years, efforts have been made to increase the surface recording density by increasing the track density at the same time as improving the linear recording density, and the latest magnetic recording apparatus has reached a track density of 110 kTPI. However, as the track density is increased, magnetic recording information between adjacent tracks interfere with each other, and the problem that the magnetization transition region in the boundary region becomes a noise source and the S / N ratio is easily lost. This directly leads to a decrease in bit error rate (Bit Error rate), which is an obstacle to improving the recording density.
In addition, since the distance between tracks is getting closer, magnetic recording devices are required to have extremely high precision track servo technology. At the same time, recording is performed widely, and playback is performed more than when recording to eliminate the influence of adjacent tracks as much as possible. In general, a method of narrowly executing is used. Although this method can minimize the influence between tracks, it is difficult to obtain a sufficient reproduction output, and it is difficult to secure a sufficient S / N ratio.

In order to ensure the thermal stability of the medium as described above, a perpendicular magnetic recording medium has been attracting attention in recent years.
In the perpendicular magnetic recording method, the demagnetizing field in the vicinity of the magnetization transition region, which is the boundary between recording bits, is achieved by orienting the easy axis of the magnetic recording layer that has been oriented in the in-plane direction of the medium in the perpendicular direction of the medium. Therefore, the higher the recording density, the more stable the magnetic field and the better the thermal fluctuation resistance. Therefore, the method is suitable for improving the surface recording density.
Further, when a backing layer made of a soft magnetic material is provided between the substrate and the perpendicular magnetic recording film, it functions as a so-called perpendicular two-layer medium, and high recording ability can be obtained. At this time, the soft magnetic underlayer plays a role of refluxing the recording magnetic field from the magnetic head, so that the recording / reproducing efficiency can be improved.

Generally, a perpendicular magnetic recording medium is provided with a backing layer (soft magnetic film) on a substrate, an underlayer film in which the easy axis of magnetization of the magnetic layer is oriented perpendicular to the substrate surface, a perpendicular magnetic recording film and a protective film made of a Co alloy. It is composed in the order. However, in recent years, it has been found that there is WATE (Wide Area Track Erasure) as a problem of the perpendicular magnetic recording medium.
This WAIT is a problem peculiar to the perpendicular magnetic recording medium. When a signal is recorded on a certain track, the signal over a wide area of several μm from the recorded track is demagnetized. Conventionally, in order to avoid this problem, a method of improving characteristics mainly by the structure of the backing layer and magnetic anisotropy has been proposed. (See Patent Document 1)
It has also been proposed that aligning the direction of magnetic anisotropy in the radial direction is effective. As this method, a method of forming a backing layer in a radial magnetic field or a method of aligning the spin direction in a certain direction with a backing layer as a laminated structure of a soft magnetic film and an antiferromagnetic film has been proposed. Yes. (See Patent Document 2)
Japanese Patent Laid-Open No. 58-166531 Japanese Patent Laid-Open No. 06-103553

However, the film formation in a magnetic field disclosed in the prior art such as Patent Document 2 described above has the following problems.
(1) It is difficult to uniformly control the magnetic field in the radial direction.
(2) The magnetic field is reduced at the inner periphery of the substrate.
Therefore, when the magnetic recording medium is further miniaturized in the future, the problem that a large magnetic field cannot be applied to the inner peripheral portion described in the item (2) is assumed to be a serious problem in this type of perpendicular magnetic recording medium. Is done.

In addition, in order to solve these problems, a technique of annealing in a magnetic field after film formation including the use of MnIr as a constituent material has also been proposed, but this requires a high processing temperature. There is a problem that causes a change in the magnetic characteristics of the soft magnetic film and the perpendicular recording layer, and there is a problem that it cannot be easily applied.
However, in the configuration using the magnetic recording medium simply provided with the backing layer as described above, it is very difficult to form a uniform easy axis in the radial direction of the substrate. There has been a demand for a magnetic recording medium that can be manufactured.

  The present invention has been made in view of the above circumstances, and solves the problem of uniformly aligning the magnetic anisotropy of the backing layer in the radial direction, and a perpendicular magnetic recording medium capable of recording and reproducing high-density information, It is an object to provide a manufacturing method and a magnetic recording / reproducing apparatus.

That is, the present invention relates to the following.
(1) The perpendicular magnetic recording medium of the present invention is a perpendicular magnetic recording medium having at least a backing layer and a perpendicular magnetic recording film on a nonmagnetic substrate, and the surface of the nonmagnetic substrate is subjected to texturing in the substrate radial direction. A plurality of the grooves along the line are formed.
(2) The perpendicular magnetic recording medium of the present invention is characterized in that the easy magnetization axis of the backing layer is in the same direction as the groove formed by the texturing process.
(3) In the perpendicular magnetic recording medium of the present invention, the nonmagnetic substrate is made of glass or silicon.
(4) In the perpendicular magnetic recording medium of the present invention, the average surface roughness of the nonmagnetic substrate after the texturing process is from 0.1 nm to 0.8 nm.
(5) In the perpendicular magnetic recording medium of the present invention, the backing layer includes at least two soft magnetic films and an intermediate layer including Ru or Re provided therebetween.

(6) The perpendicular magnetic recording medium of the present invention is characterized in that the total thickness of the soft magnetic films constituting the backing layer is 20 nm or more and 120 nm or less.
(7) The perpendicular magnetic recording medium of the present invention is characterized in that the soft magnetic film constituting the backing layer has an amorphous structure.
(8) The perpendicular magnetic recording medium of the present invention is characterized in that the nonmagnetic substrate has a diameter of 30 mm or less.
(9) A method of manufacturing a magnetic recording medium according to the present invention is a method of manufacturing a magnetic recording medium in which at least a backing layer and a perpendicular magnetic recording film are formed on a nonmagnetic substrate. A nonmagnetic substrate having a plurality of grooves is used, and at least a backing layer and a perpendicular magnetic recording film are formed on the nonmagnetic substrate.
(10) The method for producing a magnetic recording medium of the present invention is characterized in that the texturing process is performed by a step of polishing using alumina abrasive grains or diamond abrasive grains.

(11) A magnetic recording / reproducing apparatus of the present invention is a magnetic recording / reproducing apparatus comprising a magnetic recording medium and a magnetic head for recording / reproducing information on the magnetic recording medium, wherein the magnetic head is a single pole head. The magnetic recording medium is the magnetic recording medium according to any one of the preceding items.

  As described above, the perpendicular magnetic recording medium of the present invention is a perpendicular magnetic recording medium having at least a backing layer and a perpendicular magnetic recording film on a nonmagnetic substrate, and the surface of the nonmagnetic substrate is subjected to texturing treatment. By forming a plurality of grooves along the radial direction, it is possible to easily manufacture a magnetic recording medium that has an excellent error rate and does not cause a WAIT problem, and is capable of recording and reproducing high-density information. A medium, a manufacturing method thereof, and a magnetic recording / reproducing apparatus can be provided.

FIG. 1 shows a first embodiment of the magnetic recording medium of the present invention.
A magnetic recording medium 10 shown in FIG. 1 includes a first soft magnetic film 2 formed as a backing layer U on a nonmagnetic substrate 1, an intermediate layer 3 made of a Ru film, a second soft magnetic film 4, and the like. The orientation control layer 5, the perpendicular magnetic recording film 6, the protective film 7 and the lubricating film 8 laminated on the second soft magnetic film 4 are sequentially formed.

As the nonmagnetic substrate 1, a metal substrate made of a metal material such as aluminum or an aluminum alloy may be used, or a substrate made of a nonmetal material such as glass, ceramic, silicon, silicon carbide, or carbon. May be used.
Examples of the glass constituting the nonmagnetic substrate 1 include amorphous glass and crystallized glass. As the amorphous glass, general-purpose soda lime glass, aluminosilicate glass, or the like can be used. Further, as the crystallized glass, lithium-based crystallized glass can be used. As the nonmagnetic substrate 1, it is particularly preferable to use a glass substrate or a silicon substrate.

In the non-magnetic substrate 1, the average surface roughness Ra is 0.8 nm or less, preferably 0.5 nm or less, from the point of being suitable for high recording density recording that causes the magnetic head to fly low. desirable.
In addition, it is preferable that the fine waviness (Wa) on the surface of the nonmagnetic substrate 1 is 0.3 nm or less (more preferably 0.25 nm or less) from the viewpoint of being suitable for high recording density recording with a low flying height of the magnetic head. .

The texturing process for forming grooves in the radial direction on the upper surface of the non-magnetic substrate 1 means that the disk-like non-magnetic substrate 1 rotating at a low speed using a polishing liquid containing diamond abrasive grains or alumina abrasive grains. A textured tape is pressed on the surface and the textured tape is reciprocated (vibrated) in the radial direction of the nonmagnetic substrate 1 while dripping the polishing liquid, thereby forming a groove in the upper surface of the nonmagnetic substrate 1 in the radial direction. It is a process to do.
As the polishing liquid used here, for example, aqueous diamond slurry or the like can be used, and polyester-based ultrafine fiber woven fabric or the like can be used as the texturing tape. The rotational speed of the substrate 1 can be about 5 to 15 rpm, and the reciprocating speed of the texturing tape can be about 5 to 50 cm / second.
If the rotational speed of the nonmagnetic substrate 1 is excessively increased, radial texture grooves cannot be uniformly formed on the surface of the disk-shaped nonmagnetic substrate 1, and if the moving speed of the texturing tape is too slow, Similarly, the texture grooves may not be formed uniformly.

  Moreover, it is preferable that the average surface roughness Ra of the surface of the nonmagnetic substrate 1 after texturing is 0.1 nm or more and 0.8 nm or less. If the average surface roughness Ra of the surface is less than 0.1 nm, the effect of the textured groove is insufficient, and the magnetic anisotropy of the backing layer is not preferable because it deviates from the direction of the textured groove. If the average surface roughness Ra of the surface exceeds 0.8 nm, it is not preferable because the flying height of the magnetic head cannot be made sufficiently small. Further, it is not preferable because the SNR is lowered due to the deterioration of the orientation of the perpendicular magnetic recording film 6.

The first soft magnetic film 2 and the second soft magnetic film 4 are made of a soft magnetic material, and examples of these soft magnetic materials include materials containing Fe, Co, and Ni. More specific soft magnetic materials include FeCo alloys (FeCoB, FeCoSiB, FeCoZr, FeCoZrB, etc.), FeTa alloys (FeTaN, FeTaC, etc.), and Co alloys (CoTaZr, CoZrNb, CoB, etc.).
As other soft magnetic materials, soft magnetic materials having a fine crystal structure such as FeAlO, FeMgO, FeTaN, FeZrN, etc. containing Fe of 60 at% or more, or a granular structure in which fine crystal particles are dispersed in a matrix are used. May be.
It is particularly preferable that the first soft magnetic film 2 or the second soft magnetic film 4 has an amorphous structure or a fine crystal structure. This is because the effect of texturing becomes more remarkable by adopting an amorphous structure or a fine crystal structure.

As a method of forming the first soft magnetic film 2 or the second soft magnetic film 4, a sputtering method can be used. When the backing layer composed of the first and second soft magnetic films 2 and 4 and the intermediate layer 3 is formed, it can be formed in a state where a magnetic field is applied in the radial direction.
The backing layer in this embodiment preferably has a structure in which an Ru or Re intermediate layer 3 is provided between at least two soft magnetic films 2 and 4 and two soft magnetic films. An intermediate layer 3 such as Ru or Re is provided between the soft magnetic films 2 and 4, and the intermediate layer 3 is set to a predetermined thickness so that the soft magnetic films 2 and 4 provided on the upper and lower sides are antiferromagnetic. This is because they can be combined. With such a configuration, it is possible to further improve the phenomenon of WATE (Wide Area Track Erasure), which is a problem peculiar to the perpendicular magnetic recording medium.

The orientation control film 5 is for controlling the crystal orientation and crystal size of the perpendicular magnetic recording film 6 provided thereon. The material of the orientation control film 5 used as the base film of the perpendicular magnetic recording film 6 preferably has an hcp structure or an fcc structure. Ru is particularly preferable.
The thickness of the orientation control film 5 is preferably 30 nm or less. If the thickness of the orientation control film 5 exceeds 30 nm, the distance between the magnetic head and the soft magnetic backing layer at the time of recording / reproducing increases, which is not preferable because the OW (overwrite) characteristics and the resolution of the reproduced signal are lowered.
The easy axis of magnetization of the perpendicular magnetic recording film 6 is oriented in the direction perpendicular to the substrate surface (substrate thickness direction). Constituent elements of the perpendicular magnetic recording film 6 include at least Co, Pt, and oxide, and elements such as Cr, B, Cu, Ta, and Zr can be added for the purpose of improving SNR characteristics. .

Examples of the oxide constituting the perpendicular magnetic recording film 6 include SiO ₂ , SiO, Cr ₂ O ₃ , CoO, Ta ₂ O ₃ , and TiO ₂ . In the perpendicular magnetic recording film 6, the volume ratio of these oxides is preferably 15 to 40% by volume. If the volume ratio of the oxide is less than 15% by volume, the SNR characteristic becomes insufficient, which is not preferable. When the volume ratio of the oxide exceeds 40% by volume, it is not preferable because the perpendicular magnetic recording film 6 cannot obtain a coercive force enough to correspond to a high recording density.
The nucleation magnetic field (-Hn) of the perpendicular magnetic recording film 6 is preferably 1.5 (kOe) or more. -Hn of less than 1.5 (kOe) is not preferable because thermal fluctuation occurs. Note that 1 (Oe) is about 79 A / m.
The thickness of the perpendicular magnetic recording film 6 is preferably 6 to 18 nm. When the thickness of the perpendicular magnetic recording film 6 made of an oxide granular layer or the like is within this range, it is preferable because sufficient output can be secured and OW characteristics do not deteriorate.
The perpendicular magnetic recording film 6 can have a single layer structure or a structure of two or more layers made of materials having different compositions.

The coercive force Hc of the first soft magnetic film 2 or the second soft magnetic film 4 is preferably 30 (Oe) or less (preferably 10 (Oe) or less). Note that 1 (Oe) is about 79 A / m. The saturation magnetic flux density Bs of the first soft magnetic film 2 or the second soft magnetic film 4 is preferably 0.6 T or more (preferably 1 T or more).
The total thickness of the first and second soft magnetic films 2 and 4 constituting the backing layer U is preferably 20 nm or more and 120 nm or less (preferably 30 nm or more and 100 nm or less). If the total thickness of the soft magnetic film is less than 20 nm, it is not preferable because the OW characteristics deteriorate. On the contrary, if the total film thickness exceeds 120 nm, the effect of the texturing grooves becomes insufficient, which is not preferable.

The protective film 7 is for preventing corrosion of the perpendicular magnetic recording film 6 and preventing damage to the surface of the medium when the magnetic head comes into contact with the medium. Conventionally known materials can be used, for example, C, SiO _2. And those containing ZrO ₂ can be used. The thickness of the protective film 7 is preferably 1 nm or more and 5 nm or less because the distance between the magnetic head and the magnetic recording medium can be reduced.
The lubricating film 8 is preferably made of a conventionally known material such as perfluoropolyether, fluorinated alcohol, fluorinated carboxylic acid or the like.

  In the perpendicular magnetic recording medium 10 of the present embodiment, the surface of the nonmagnetic substrate 1 is textured in the perpendicular magnetic recording medium having at least the backing layer U and the perpendicular magnetic recording film 6 on the nonmagnetic substrate 1. Thus, since the magnetic recording medium is formed with grooves along the radial direction of the substrate, it becomes a magnetic recording medium capable of recording and reproducing high-density information.

  FIG. 2 shows an example of a magnetic recording / reproducing apparatus using the magnetic recording medium 10 having the above structure. The magnetic recording / reproducing apparatus shown here includes a magnetic recording medium 10 having the structure described above, a medium driving unit 11 that rotationally drives the magnetic recording medium 10, a magnetic head 12 that records and reproduces information on the magnetic recording medium 10, and A head driving unit 13 and a recording / reproducing signal processing system 14 are provided. The recording / reproducing signal processing system 14 can process the input data and send the recording signal to the magnetic head 12, or can process the reproducing signal from the magnetic head 12 and output the data.

  Hereinafter, an example is shown and the operation effect of the present invention is clarified. However, the present invention is not limited to the following examples.

Example 1
Texturing processing was performed on the glass substrate (Ohara Corporation crystallized substrate TS10-SX, diameter 0.85 inch) in the substrate radial direction.

In the texturing process, an aqueous diamond slurry containing diamond abrasive grains having an average particle diameter of 0.1 μm was used as the polishing liquid, and a polyester ultrafine fiber woven fabric was used as the texturing tape. The rotation speed of the substrate 1 was 10 rpm, and the reciprocating speed of the texturing tape was 15 cm / second. After the texturing process, the surface of the substrate is cleaned, and after the surface of the substrate is cleaned, the substrate is accommodated in a film forming chamber of a DC magnetron sputtering apparatus (C-3010 manufactured by Anerva Co., Ltd.) The film formation chamber was evacuated to 1 × 10 ⁻⁵ Pa. On this substrate, 89Co-4Zr-7Nb (Co content 89 at%, Zr content 4 at%, Nb content 7 at%) is 50 nm, Ru is 0.8 nm, and the second soft magnetic film is used as the first soft magnetic film. 89Co-4Zr-7Nb was deposited to a thickness of 50 nm to form a three-layer backing layer. It was confirmed by a vibration magnetic property measuring device (VSM) that the easy axis of magnetization of the laminated film was in the substrate radial direction (along the groove formed by texturing).
Next, Ru was formed to a thickness of 20 nm as an orientation control film, and 60 Co-10Cr-20Pt-10SiO ₂ was formed to a thickness of 12 nm as a perpendicular magnetic recording film. Next, a protective film having a thickness of 4 nm was formed by a CVD method. Next, a lubricating film made of perfluoropolyether was formed by a dipping method to obtain a perpendicular magnetic recording medium.

(Comparative Example 1)
A perpendicular magnetic recording medium was manufactured according to Example 1 except that the texturing process was not performed.
(Comparative Example 2)
A magnetic recording medium was manufactured according to Comparative Example 1 except that a backing layer was formed by applying a magnetic field in the substrate radial direction.
The recording / reproducing characteristics of each of the perpendicular magnetic recording media of these examples and comparative examples were evaluated.
The recording / reproduction characteristics were evaluated using a read / write analyzer RWA1632 manufactured by GUZIK, USA, and a spin stand S1701MP.

For the evaluation of the recording / reproducing characteristics, the recording frequency condition was measured at a linear recording density of 800 kFCI using a magnetic head using a single pole magnetic pole and a GMR element in the reproducing part.
For evaluation of WAIT, after writing an 800 kFCI signal, the degree of error rate degradation after writing a 100 kFCI signal 100,000 times on a track 3 μm apart was measured. The evaluation results are shown in Table 1 below.

  From the results shown in Table 1, it was confirmed that the sample of Example 1 was less deteriorated in error rate due to WATE than the samples of Comparative Examples 1 and 2. When examined in more detail, it was found that the sample of Comparative Example 2 had a large error rate deterioration on the inner peripheral side of the substrate. This is presumably because the applied magnetic field tends to be insufficient on the inner peripheral side of the substrate when a magnetic layer is applied in the radial direction of the substrate to form the backing layer.

(Examples 2 to 4)
A plurality of magnetic recording media were produced in the same manner as in Example 1 except that the average surface roughness Ra after the texturing process was changed by changing the texturing process conditions and the grain size of the diamond abrasive grains. The evaluation results are shown in Table 2 below.

  From the results shown in Table 2, the perpendicular magnetic recording medium having an average surface roughness Ra after texturing of 0.1 nm or more and 0.8 nm or less has particularly low error rate deterioration, and an excellent result can be obtained. . From this, it has been found that when the average surface roughness Ra after texturing is 0.1 nm or more and 0.8 nm or less, the error rate deterioration can be suppressed more satisfactorily.

(Examples 5-7)
A plurality of perpendicular magnetic recording media were produced according to Example 1 except that the material of the nonmagnetic substrate was changed. The evaluation results of these perpendicular magnetic recording media are shown in Table 3 below.

  From the results shown in Table 3, regardless of the material of the non-substrate substrate, the perpendicular magnetic recording medium in which the textured grooves were formed had little error rate deterioration, and excellent characteristics could be obtained. It was also found that among non-magnetic substrates made of various materials, glass substrates and silicon substrates are particularly excellent in terms of error rate degradation.

(Examples 8 to 12)
A plurality of perpendicular magnetic recording media were manufactured in accordance with Example 1 except that the material of the soft magnetic film constituting the backing layer was changed. The evaluation results of these perpendicular magnetic recording media are shown in Table 4 below.

  From the results shown in Table 4, it was possible to obtain excellent characteristics in terms of error rate deterioration in any sample regardless of the material of the backing layer. Among the constituent materials of the backing layer, CoZrNb (Example 1), CoTaZr (Example 8), and FeCoB (Example 9) are particularly excellent. When these film structures were examined with an XRD apparatus, no clear diffraction peak could be observed in the analysis results of any film. From this, it can be presumed that all the films of Examples 1, 8, and 9 have an amorphous structure, and the amorphous structure makes the effect of the groove formed by texturing treatment more effective. It can be seen that it is.

(Examples 13 to 16)
A plurality of perpendicular magnetic recording media were manufactured in accordance with Example 1 except that the thickness of the soft magnetic film constituting the backing layer was changed. The evaluation results of these perpendicular magnetic recording media are shown in Table 5 below.

  From the results shown in Table 5, Examples 1, 13, 14, and 15 in which the total thickness of the soft magnetic film constituting the backing layer is in the range of 20 nm to 120 nm are particularly excellent in terms of error rate degradation. I understand. From this, it was found that the thickness of the backing layer is more preferably in the range of 20 nm or more and 120 nm or less.

FIG. 1 is a sectional view showing a first embodiment of a magnetic recording medium according to the present invention. FIG. 2 is a block diagram showing an example of a magnetic recording / reproducing apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Nonmagnetic board | substrate, 2 ... 1st soft magnetic film, 3 ... Intermediate | middle layer, 4 ... 2nd soft magnetic film, 5 ... Orientation control layer, 6 ... Perpendicular magnetic recording film, 7 ... Protective film, 8 ... Lubrication film, DESCRIPTION OF SYMBOLS 10 ... Magnetic recording medium, 11 ... Medium drive part, 12 ... Magnetic head, 13 ... Head drive part, 14 ... Recording / reproduction signal processing system

Claims (11)

  In a perpendicular magnetic recording medium having at least a backing layer and a perpendicular magnetic recording film on a nonmagnetic substrate, a plurality of grooves along the radial direction of the substrate are formed on the surface of the nonmagnetic substrate by texturing. A perpendicular magnetic recording medium.   2. The perpendicular magnetic recording medium according to claim 1, wherein an easy axis of magnetization of the backing layer is in the same direction as a groove formed by the texturing process.   The perpendicular magnetic recording medium according to claim 1, wherein the nonmagnetic substrate is made of glass or silicon.   4. The perpendicular magnetic recording medium according to claim 1, wherein an average surface roughness of the non-magnetic substrate after the texturing process is 0.1 nm or more and 0.8 nm or less. 5.   5. The perpendicular magnetic recording medium according to claim 1, wherein the backing layer includes at least two soft magnetic films and an intermediate layer including Ru or Re provided therebetween. .   6. The perpendicular magnetic recording medium according to claim 1, wherein the total thickness of the soft magnetic film constituting the backing layer is 20 nm or more and 120 nm or less.   7. The perpendicular magnetic recording medium according to claim 1, wherein the soft magnetic film constituting the backing layer has an amorphous structure.   The perpendicular magnetic recording medium according to claim 1, wherein the nonmagnetic substrate has a diameter of 30 mm or less.   In a method of manufacturing a magnetic recording medium in which at least a backing layer and a perpendicular magnetic recording film are formed on a nonmagnetic substrate, the nonmagnetic substrate is formed using a nonmagnetic substrate in which a plurality of grooves along the radial direction are formed by texturing on the surface. A method of manufacturing a perpendicular magnetic recording medium, comprising forming at least a backing layer and a perpendicular magnetic recording film on a substrate.   The method of manufacturing a perpendicular magnetic recording medium according to claim 9, wherein the texturing process is performed by a step of polishing using alumina abrasive grains or diamond abrasive grains. A magnetic recording / reproducing apparatus comprising a magnetic recording medium and a magnetic head for recording / reproducing information on / from the magnetic recording medium, wherein the magnetic head is a single pole head, and the magnetic recording medium comprises: A magnetic recording / reproducing apparatus according to any one of the above.

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