JP2002334415A - Magnetic recording medium and magnetic storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a perpendicular magnetic recording medium which exhibits excellent thermal stability in the recording magnetic domain where high density recording is carried out and of which the information can be reproduced with low noise and high S/N. SOLUTION: The magnetic recording medium is provided with an intrasurface soft magnetism layer 3, a perpendicular soft magnetism layer 4 and a recording layer 5 on a substrate 1. The magnetic flux from a recording magnetic domain 15 of the recording layer 5 first becomes aslant in the perpendicular soft magnetism layer 4, and is then oriented to an intrasurface direction in the intrasurface soft magnetism layer 3. Thus a magnetic loop of a horseshoe shape is easily formed between the intrasurface magnetism layer 3 and the recording layer 5. Consequently, the recording magnetic domain of the recording layer 5 is more stabilized than before. Furthermore, since the magnetic fluctuation of the intrasurface magnetism layer 3 is reduced and noise is made smaller, information can be reproduced with high S/N.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium and a magnetic storage device using the same, and more particularly, to a magnetic head such as a hard disk, a floppy (registered trademark) disk, etc. The present invention relates to a magnetic recording medium of a contact type and a magnetic storage device using the same.

[0002]

2. Description of the Related Art Magnetic storage devices are used as large-capacity storage devices such as large servers, parallel computers, personal computers, network servers, movie servers, and mobile PCs. The magnetic storage device includes a magnetic recording medium on which information is magnetically recorded, and a magnetic head for recording or reproducing information. The magnetic recording medium includes a disk-shaped substrate, on which a ferromagnetic thin film such as a cobalt alloy is formed as a recording layer by a sputtering method or the like. On the ferromagnetic thin film, a protective film and a lubricating film are formed in order to improve sliding resistance and corrosion resistance.

In recent years, in order to increase the capacity of magnetic storage devices,
2. Description of the Related Art A method of recording a fine recording magnetic domain on a magnetic recording medium to improve a recording density has been advanced. In order to finely record the recording magnetic domains, a so-called perpendicular magnetic recording method has been proposed in which recording magnetic domains having magnetization in a direction perpendicular to the film surface are recorded on a recording layer. For the practical use of the perpendicular magnetic recording system, it is necessary to reduce the noise generated from the medium at the time of information reproduction while improving the recording density by making the recording magnetic domain fine.

As a method for reducing noise from a medium, it is known that a method in which a soft magnetic layer having in-plane magnetization (hereinafter, referred to as an in-plane soft magnetic layer) is provided under the recording layer is effective. ing. When the in-plane soft magnetic layer is formed as an underlayer of the recording layer, a leakage magnetic field from adjacent recording magnetic domains having magnetizations of opposite directions in the recording layer passes through the in-plane soft magnetic layer.
At this time, in the cross section of the recording layer and the in-plane soft magnetic layer, the leakage magnetic field from the recording bit forms a horseshoe-shaped magnetic loop (magnetic circuit) between the recording layer and the in-plane soft magnetic layer. Since the recording magnetic domain is magnetically stabilized by the loop of the leakage magnetic field, noise from the medium is reduced.

[0005]

However, even if an in-plane soft magnetic layer is formed under the recording layer, noise generated during information reproduction has not been sufficiently reduced. This is because the in-plane soft magnetic layer formed of a soft magnetic material having in-plane magnetization is formed in contact with the recording layer having perpendicular magnetization, so that the in-plane soft magnetic layer has magnetic fluctuation (fluctuation of magnetization). It is thought that this is due to the occurrence of Therefore, in order to prevent noise due to the magnetic fluctuation of the in-plane soft magnetic layer,
It has been proposed to sandwich a non-magnetic layer between the in-plane soft magnetic layer and the recording layer.

However, by interposing a non-magnetic layer between the in-plane soft magnetic layer and the recording layer, noise due to magnetic fluctuation of the in-plane soft magnetic layer can be reduced, but the recording magnetic domain of the recording layer can be reduced. There is a problem that magnetic stability, especially thermal stability, is reduced.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a perpendicular magnetic recording medium which has excellent thermal stability of recording magnetic domains and can reproduce information with low noise. It is in.

A second object of the present invention is to withstand thermal fluctuations,
An object of the present invention is to provide a magnetic storage device capable of reproducing information recorded at a high areal recording density at a high S / N.

[0009]

According to a first aspect of the present invention, in a magnetic recording medium, a recording layer having perpendicular magnetization, an in-plane soft magnetic layer, the recording layer and the in-plane soft magnetic layer, And a perpendicular soft magnetic layer located therebetween.

The magnetic recording medium of the present invention comprises a perpendicular soft magnetic layer between the recording layer having perpendicular magnetization and the in-plane soft magnetic layer, instead of the above-described non-magnetic layer of the conventional magnetic recording medium. I have. The perpendicular soft magnetic layer is formed of, for example, a soft magnetic material exhibiting perpendicular magnetization in a temperature range of 10 ° C to 200 ° C. By providing such a perpendicular soft magnetic layer in place of the nonmagnetic layer, it was possible to reduce the noise due to the magnetic fluctuation of the in-plane soft magnetic layer and to increase the thermal stability of the recording magnetic domain. The reason will be described below.

Since the perpendicular soft magnetic layer has magnetic properties such that the magnetization is easily directed to the direction of the magnetic field, as shown in FIG.
Is stabilized in the direction perpendicular to the film surface by the exchange coupling force with the recording layer 5 having perpendicular magnetization, while the magnetization 13 existing on the in-plane soft magnetic layer 3 has magnetization in the in-plane direction. Due to the exchange coupling force with the in-plane soft magnetic layer 3, the layer is inclined and stabilized with respect to the film surface. As described above, the magnetization 13 existing on the in-plane soft magnetic layer 3 side of the perpendicular soft magnetic layer 4 includes an in-plane component. Here, the magnetization 14 existing on the side of the perpendicular soft magnetic layer 4 of the in-plane soft magnetic layer 3 made of the soft magnetic material also tilts obliquely with respect to the film surface due to the exchange coupling force with the perpendicular soft magnetic layer 4. ing. That is, the perpendicular soft magnetic layer 4 and the in-plane soft magnetic layer 3
In the boundary portion, the magnetizations 13 and 14 of the perpendicular soft magnetic layer 4 and the in-plane soft magnetic layer 3 are oriented in the same direction obliquely with respect to the film surface. Then, the magnetization of the in-plane soft magnetic layer 3 is gradually oriented in the in-plane direction as the distance from the perpendicular soft magnetic layer 4 increases. Therefore, the magnetic flux in the direction perpendicular to the film surface generated from the recording magnetic domain 15 of the recording layer 5 is directed obliquely in the perpendicular soft magnetic layer 4,
In the in-plane direction. That is, the presence of the perpendicular soft magnetic layer 3 causes the direction of the magnetic flux to change stepwise from the perpendicular direction to the in-plane direction.
Below 5, 16, and 17, a horseshoe-shaped magnetic flux loop as shown in FIG. 2 is easily formed. As described above, since the horseshoe-shaped magnetic flux loop is easily formed in the magnetic recording medium of the present invention, it is possible to stably hold the recording magnetic domain of the recording layer, and to improve the thermal stability of the recording magnetic domain. Have been.

Further, in the magnetic recording medium of the present invention, the magnetic fluctuation of the in-plane soft magnetic layer can be reduced by forming the perpendicular soft magnetic layer between the recording layer and the in-plane soft magnetic layer. This is because the perpendicular soft magnetic layer made of a soft magnetic material is formed in contact with the in-plane soft magnetic layer, so that the perpendicular soft magnetic layer and the in-plane soft magnetic layer are formed at the boundary between the perpendicular soft magnetic layer and the in-plane soft magnetic layer. It is considered that the magnetizations of the vertical soft magnetic layer were directed in the same direction, and the magnetic flux of the perpendicular soft magnetic layer could surely enter the in-plane soft magnetic layer. In a conventional magnetic recording medium in which the in-plane soft magnetic layer and the recording layer are in contact with each other, the magnetization of the recording layer is perpendicular to the magnetization of the in-plane soft magnetic layer. It is probable that it was not possible to sufficiently penetrate into the inner soft magnetic layer, so that magnetic fluctuation occurred in the in-plane soft magnetic layer. The magnetic recording medium of the present invention comprises:
The vertical soft magnetic layer can reduce the magnetic fluctuation of the in-plane soft magnetic layer, so that noise based on the fluctuation can be reduced.

In the magnetic recording medium of the present invention, in order to prevent the magnetization of the recording layer from following the magnetization of the perpendicular soft magnetic layer, the perpendicular soft magnetic layer has a coercive force of 200 Oe or less, 100
It is preferable to have a saturation magnetization of emu / cc or more and a perpendicular magnetic anisotropic magnetic field of 5 kOe or less. The thickness of the perpendicular soft magnetic layer is desirably 5 nm to 20 nm.

In the present specification, the term "anisotropic magnetic field" refers to a magnetic field at which magnetization is saturated when a magnetic field is applied in the direction of hard magnetization. In the perpendicular magnetic film, the direction of the hard axis is an in-plane direction.

The perpendicular soft magnetic layer comprises, for example, at least one transition metal element selected from Fe, Co and Ni, and at least one element selected from Pd, Pt, Pr, Tb, Gd, Cr and Ta. It is preferably a Co / Pd artificial lattice layer because magnetic properties can be easily fine-tuned by changing the composition ratio of Co and Pd, the thickness of each layer, and the like. Is preferred. Other than such materials, for example, Co-Cr
An alloy thin film, a Tb-Fe-Co alloy thin film, or an Fe-Pt ordered alloy thin film can also be used.

In the present invention, the perpendicular magnetic permeability of the perpendicular soft magnetic layer is preferably larger than the in-plane magnetic permeability, and the perpendicular magnetic permeability is determined by the magnetization existing on the recording layer side of the perpendicular soft magnetic layer. Is preferably 100 or more in order to easily follow the direction of magnetization of the recording layer.

The recording layer of the magnetic recording medium of the present invention has a coercive force of at least 2 kOe and a coercivity of 200 emu so that a recording bit (recording magnetic domain) is stable against external heat or a magnetic field and a sufficient reproduction output is generated. / Cc or more. The thickness of the recording layer allows a sufficient reproduction output to be obtained during information reproduction,
The thickness is preferably 10 nm to 100 nm so that a recording magnetic field from the magnetic head can be sufficiently applied to the recording layer during information recording.

Materials for forming the recording layer include, for example, Tb
FeCo, DyFeCo, TbDyFeCo, Co / P
d artificial lattice layer, CoCr, FePt, etc. can be used. In particular, (1) the size of the recording magnetic domain is small and suitable for high-density recording, and (2) the squareness ratio is high and the thermal stability is excellent. A Co / Pd artificial lattice layer is preferred for two reasons.

In the magnetic recording medium of the present invention, a non-magnetic intermediate layer may be further formed between the perpendicular soft magnetic layer and the recording layer. Since the non-magnetic intermediate layer can prevent the magnetic particles having a relatively large particle diameter constituting the perpendicular soft magnetic layer from being reflected on the recording layer, the magnetic particles of the recording layer can be made minute. . In the non-magnetic intermediate layer, for example, S
i, Pd, In, Sn, C, B, Al, Cu, Zn, P
t, Ru, Ag, Au, Ti, Gd, Tb, Er, D
A thin film formed of at least one element selected from y, Cr, Mn, Ta, Nb, and Zr, or a thin film formed of a nitride or oxide formed by adding nitrogen or oxygen to these elements is used. be able to.

In the magnetic recording medium of the present invention, the in-plane soft magnetic layer is formed of a soft magnetic material exhibiting in-plane magnetization in a temperature range of 10 ° C. to 200 ° C.
o, rare earth-transition metal materials such as TmFeCo, GdFeCo, FeTaC, CoNbZr, CoTaZr, F
Materials such as eAlSi may be used.

According to a second aspect of the present invention, claims 1 to 1 are provided.
8, a magnetic head for recording and reproducing information, and moving means for relatively moving the magnetic head with respect to the magnetic recording medium;
There is provided a magnetic storage device characterized by having signal processing means for performing signal processing on a recording signal input to the magnetic head and a reproduction signal from the magnetic head.

Since the magnetic storage device of the present invention includes the magnetic recording medium of the present invention, it has excellent thermal stability and can reproduce information recorded at a high areal recording density with a high S / N.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the magnetic recording medium according to the present invention will be specifically described below with reference to the drawings.
In the following embodiments, a magnetic disk (hard disk) was manufactured as a magnetic recording medium. However, the present invention is also applicable to a magnetic recording medium such as a floppy disk, a magnetic tape, and a magnetic card that comes in contact with a magnetic head during recording and reproduction. Applicable.

Embodiment 1 FIG. 1 shows a schematic sectional view of a magnetic recording medium of the present invention. The magnetic recording medium 9 includes an adhesive layer (nonmagnetic layer) 2
An in-plane soft magnetic layer 3, a perpendicular soft magnetic layer 4, a recording layer 5, a protective layer 6, and a lubricating layer 7 are provided. The magnetic recording medium 9 having such a structure was manufactured by the following method.

First, a glass substrate 1 having a diameter of 65 mm was prepared, and a nonmagnetic layer 2 made of Ti having a film thickness of 5 nm was formed as an adhesion layer on the glass substrate 1 by using a continuous sputtering apparatus. Next, on the non-magnetic layer 2, as an in-plane soft magnetic layer 3,
Fe ₇₉ Ta ₉ C ₁₂ was formed to a thickness of 400 nm.
Further, the formed Fe ₇₉ Ta ₉ C ₁₂ is heated in a vacuum at a temperature of 450 ° C. for 30 seconds by a carbon heater, and then gradually cooled to obtain an in-plane soft magnetic layer containing an Fe microcrystalline structure in the film. 3 was formed. The obtained in-plane soft magnetic layer 3 has a coercive force of 0.5 [Oe] and a saturation magnetization of 1200 [emu / c].
c], the magnetic permeability was 2800.

Next, in an Ar gas, a Co target and P
By performing DC sputtering while alternately opening and closing the shutters of the d target, the perpendicular soft magnetic layer 4 having an artificial lattice structure in which Co layers and Pd layers were alternately stacked was formed. C
The film thickness per layer of the o layer is 0.063 nm, the film thickness per layer of the Pd layer is 0.69 nm, and the Co layer and the Pd
The number of stacked layers was 10 each. The obtained perpendicular soft magnetic layer 4 has a coercive force of 120 [Oe] and a saturation magnetization of 110 [Oe].
[Emu / cc], the vertical anisotropic magnetic field was 3 [kOe], and the magnetic permeability was 100.

Next, in Ar gas, while alternately opening and closing the shutters of the Co target and the Pd target, DC
By sputtering, the recording layer 5 having an artificial lattice structure in which Co layers and Pd layers were alternately stacked was formed. Co
The thickness of each layer was 0.12 nm, the thickness of each Pd layer was 0.85 nm, and the number of layers of the Co layer and the Pd layer was 26 each.

The coercive force of the obtained recording layer is 3 kOe,
The saturation magnetization was 230 [emu / cc], the perpendicular anisotropic magnetic field was 14 [kOe], and the magnetic permeability was 3.5.

Next, after forming an amorphous carbon protective layer 6 on the recording layer 5 to a thickness of 3 nm by a plasma CVD method, the substrate was taken out of the film forming apparatus. Finally,
1 n of a perfluoropolyether lubricant on the protective layer 6
The lubricating film 7 was formed by applying the solution with a thickness of m.

Thus, a magnetic recording medium having the laminated structure shown in FIG. 1 was manufactured.

Example 2 In this example, a magnetic recording medium was manufactured in the same manner as in Example 1 except that a nonmagnetic intermediate layer was formed between the perpendicular soft magnetic layer and the recording layer. The intermediate layer is composed of 80 at% Pd, 1
It was made of 5 at% Si and 5 at% N, and was formed to a thickness of 2 nm by simultaneously sputtering a Pd target and a SiN target in an Ar gas atmosphere.

Example 3 The magnetic recording medium manufactured in Example 1 was incorporated in a magnetic storage device 200 having a schematic plane structure as shown in FIG. The magnetic storage device 200 includes a magnetic recording medium 9, a rotation driving unit 8 for rotationally driving the magnetic recording medium 9, a magnetic head 10 having a single-pole type write element and a GMR read element, and a magnetic head 10. The head drive device 11 moves relatively to the recording medium, and the recording / reproduction signal processing device 12 encodes data to be recorded on the magnetic recording medium 9 and decodes a reproduction signal from the magnetic recording medium 9.

By driving such a magnetic storage device, the magnetic spacing (the distance between the main pole surface of the magnetic head 10 and the recording layer surface of the magnetic recording medium 9) is maintained at 13 nm.
Linear recording density 1000kBPI, track density 150kT
Information was recorded under the conditions of PI, and the recorded information was reproduced to evaluate the recording / reproducing characteristics. As a result, a total SNR of 24.5 dBo-p / rms was obtained. Further, recording and reproduction could be performed at an areal recording density of 150 gigabit / square inch.

Comparative Example 1 In this comparative example, a magnetic recording medium was manufactured in the same manner as in Example 1 except that a Pd layer having a thickness of 8 nm was formed instead of the perpendicular soft magnetic layer.

Comparative Example 2 In this comparative example, the recording layer was formed directly on the in-plane soft magnetic layer without forming the perpendicular soft magnetic layer between the in-plane soft magnetic layer and the recording layer. In the same manner as in Example 1, a magnetic recording medium was produced.

Comparative Example 3 The magnetic recording medium manufactured in Comparative Example 1 was incorporated into the magnetic storage device shown in FIG. 3 in the same manner as in Example 3, and the recording and reproducing characteristics were evaluated under the same conditions as in Example 3. Was 18.5 dBo-p / rms, and sufficient recording and reproduction could not be performed. Furthermore, areal recording density of 150 Gbit /
When recording and reproducing at a recording density of square inches, the number of bit errors after 100,000 head seek tests from the inner circumference to the outer circumference was 150 bits / plane or less, and the average failure interval was 190,000 hours.

Next, the electromagnetic conversion characteristics of each of the magnetic recording media prepared in Examples 1 and 2 and Comparative Examples 1 and 2 were measured using a recording / reproducing tester of a spin stand. As a magnetic head of the recording / reproducing tester, a composite head of a single-pole type write element and a GMR read element was used. The single-pole main pole of the single-pole type write element had an effective write track width of 110 nm and Bs of 2.1T. The effective track width of the GMR element is 97 nm,
The shield spacing was 45 nm. The distance between the surface of the main magnetic pole of the magnetic head and the surface of the magnetic layer of the magnetic recording medium during the recording / reproducing test was 13 nm. Table 1 shows the measurement results.

[0038]

[Table 1]

In Table 1, S / Nd is 500 kFCI.
Is the S / N. As is clear from Table 1, good S / N was obtained in the magnetic recording media of Examples 1 and 2, whereas 10 dBo-p / rms was obtained in the magnetic recording media of Comparative Examples 1 and 2. Only less than S / N was obtained.

Next, the thermal demagnetization rates of the magnetic recording media of Examples 1 and 2 and Comparative Examples 1 and 2 were measured. The thermal demagnetization rate is a linear recording density of 100 k in an environment of 24 ° C.
It was obtained by measuring the average reproduction output of one track up to about 4000 seconds as the rate of change of the reproduction signal amplitude with respect to time when reproducing a signal recorded by FCI. FIG.
The results of the above-described measurement, that is, how the output of the reproduced signal changes with the measurement time for the magnetic recording media of Example 1 and Comparative Example 1 are shown below. From FIG. 4, it can be seen that in the magnetic recording medium of Example 1, the reproduction signal output was almost constant during the measurement time of 4000 seconds, and there was no thermal demagnetization. On the other hand, in the magnetic recording medium of Comparative Example 1, it can be seen that the reproduction signal output gradually decreases with time and thermal demagnetization occurs. Table 1 shows the values of the thermal demagnetization rates obtained as described above for the respective magnetic recording media. In the magnetic recording media of Examples 1 and 2, the thermal demagnetization rate was zero, whereas in the magnetic recording media of Comparative Examples 1 and 2, the thermal demagnetization rate was −
It was over 5.0.

As compared with the magnetic recording media of Examples 1 and 2,
The S / N was low in the magnetic recording media of Comparative Examples 1 and 2, and the cause of the thermal demagnetization was that the magnetic recording media of Examples 1 and 2 had a clear linearity in the shape of the magnetization transition region. On the other hand, in the magnetic recording media of Comparative Examples 1 and 2, the shape of the magnetization transition region is disordered, which is likely to be thermally disturbed.

The magnetic recording media of Examples 1 and 2 and Comparative Examples 1 and 2 were set to 1000 k on track.
When the error rate was measured by the BPI, the error rate was 1 × 10 ⁻⁵ or less for the magnetic recording media of Examples 1 and 2, whereas the error rate was 1 × 10 ⁻⁴ for the magnetic recording media of Comparative Examples 1 and 2.
As described above, the error rate was increasing.

Although the magnetic recording medium of the present invention has been described in detail with reference to the embodiments, the present invention is not limited thereto.

[0044]

The magnetic recording medium of the present invention has a perpendicular soft magnetic layer formed of a soft magnetic material exhibiting perpendicular magnetization between the recording layer and the in-plane soft magnetic layer. A stable magnetic loop is formed between the magnetic layer and the soft magnetic layer, so that the thermal stability of the recording magnetic domain is improved and noise due to the magnetic fluctuation of the in-plane soft magnetic layer is reduced. The magnetic storage device of the present invention including such a magnetic recording medium has a capacity of 150 Gbit / s.
Information recorded at a high areal recording density of square inches
N can be played.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a magnetic recording medium according to the present invention.

FIG. 2 is a diagram schematically showing the state of magnetization of a recording layer, a perpendicular soft magnetic layer, and an in-plane soft magnetic layer of a magnetic recording medium according to the present invention.

FIG. 3 is a schematic plan view of a magnetic storage device according to the present invention.

FIG. 4 is a graph of a reproduction signal output with respect to time of the magnetic recording media of Example 1 and Comparative Example 1.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 glass substrate 2 nonmagnetic layer 3 in-plane soft magnetic layer 4 perpendicular soft magnetic layer 5 recording layer 6 protective film layer 7 lubricating film layer 8 rotation drive unit 9 magnetic recording medium 10 magnetic head 11 magnetic head drive unit 12 signal processing circuit unit 200 magnetic storage device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 5/738 G11B 5/738 H01F 10/08 H01F 10/08 10/16 10/16 (72) Inventor Ryo Yano, 1-88 Ushitora, Ibaraki-shi, Osaka Prefecture, Hitachi Maxell Co., Ltd. (72) Inventor Takanobu Takayama 1-188, Ushitora, Ibaraki City, Osaka Prefecture, Hitachi, Ltd. 1-88 Ushitora, Ibaraki-shi, Osaka, Hitachi Maxell, Ltd. 1-88 Ushitora, Ibaraki-shi Hitachi Maxell Co., Ltd. (72) Inventor Fujita Shioji 1-88 Ushitora, Ibaraki-shi, Osaka F-term in Hitachi Maxell Co., Ltd. Remarks) 5D006 BB01 BB07 BB08 CA01 CA03 CA06 DA03 EA03 FA04 5E049 AA04 BA06 GC01

Claims (10)

[Claims] 1. A magnetic recording medium, comprising: a recording layer having perpendicular magnetization; an in-plane soft magnetic layer; and a perpendicular soft magnetic layer located between the recording layer and the in-plane soft magnetic layer. Magnetic recording medium. 2. The perpendicular soft magnetic layer has a coercive force of 200 Oe or less, a saturation magnetization of 100 emu / cc or more,
2. The magnetic recording medium according to claim 1, wherein the magnetic recording medium has a perpendicular anisotropic magnetic field of Oe or less. 3. The vertical soft magnetic layer has a thickness of 5 nm to 20 nm.
3. The magnetic recording medium according to claim 1, wherein the magnetic recording medium has a film thickness. 4. The recording layer according to claim 1, wherein the recording layer is an artificial lattice layer having a structure in which layers made of Co and layers made of Pd are alternately stacked. Magnetic recording medium. 5. The perpendicular soft magnetic layer comprises Fe, Co and N
and at least one transition metal element selected from the group consisting of i and at least one element selected from the group consisting of Pd, Pt, Pr, Tb, Gd, Cr, and Ta. Item 5. The perpendicular magnetic recording medium according to any one of items 1 to 4. 6. The magnetic recording medium according to claim 5, wherein the perpendicular soft magnetic layer is an artificial lattice layer having a structure in which layers made of Co and layers made of Pd are alternately stacked. 7. The magnetic recording medium according to claim 1, further comprising a nonmagnetic layer between the recording layer and the perpendicular soft magnetic layer. 8. The recording layer has a coercive force of 2 kOe or more,
8. The magnetic recording medium according to claim 1, wherein the magnetic recording medium has a saturation magnetization of 200 emu / cc or more. 9. A magnetic recording medium according to claim 1, a magnetic head for recording and reproducing information, and a magnetic head for moving the magnetic head relative to the magnetic recording medium. And a signal processing means for performing signal processing on a recording signal input to the magnetic head and a reproduction signal from the magnetic head. 10. The magnetic storage device according to claim 9, further comprising a driving device for rotationally driving the magnetic recording medium.