JPH10112408A - In-plane magnetic recording medium and magnetic storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic storage device of a large capacity which attain super-high density recording of not less than one gigabits per square inch. SOLUTION: On a substrate 11, underlying films 12, 12' made of at least one element selected from the group consisting of V, Nb, Mo, Ta, W and Ti, or underlying films 12, 12' containing Cr and at least one element selected from the group consisting of V, Nb, Mo, Ta, W and Ti, are provided. On the underlying films 12, 12', magnetic films 13, 13' containing at least Co, Cr, Pt and Nb are provided, thus producing an in-plane magnetic recording medium. For a reproducing section of a magnetic head for reproducing this in-plane magnetic recording medium, a magnetoresistance effect element is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic recording medium such as a magnetic drum, a magnetic tape, a magnetic disk, and a magnetic card, and a magnetic storage device, and more particularly, to an ultra-high density recording of 1 gigabit or more per square inch. The present invention relates to a longitudinal magnetic recording medium and a magnetic storage device using the longitudinal magnetic recording medium.

[0002]

2. Description of the Related Art With the rapid spread of personal computers and the increase in the amount of information handled on an individual level, magnetic disks have been required to have even larger capacities. To meet this demand, it is necessary to increase the bit density per unit volume of the magnetic disk medium. In this case, it is an important technical subject to develop a medium having a high coercive force and low noise at a recording density of 150 kFCI or more.

In a conventional general longitudinal magnetic recording medium, a Cr underlayer is provided on a substrate, and a CoNi-based or C
A structure in which an oCrTa magnetic film is laminated is generally used. However, a medium using these magnetic films has a low coercive force, and it is difficult to record at 150 kFCI or more. Therefore, recently, it has been studied to use CoCrPt, which has a large magnetic anisotropy and can increase the coercive force, as a magnetic film material (for example, J. Appl. Phys. 73).
(10), p5560-5562, 1993). However, when CoCrPt is used as a magnetic film material,
Certainly, the coercive force is increased, but there is a problem that noise is increased due to strong interaction between magnetic crystal grains.

Therefore, a method of adding Ta to CoCrPt (for example, Jpn. J. Appl. Phys. 32, p.
3823-3827, 1993) and CoCrPt with T
A method of adding i (Japanese Patent Laid-Open No. 7-50008) has been proposed, and suppression of noise increase has been proposed. Further, although it is a perpendicular magnetic recording medium, it has been reported that when Nb is added to CoCr, the direction of the easy axis of magnetization is oriented more perpendicularly, and the coercive force measured in the perpendicular direction to the film becomes higher. Technical report, MR95-27, p7-13, 1
995).

[0005]

As described above, CoCr is used.
When Pt is used as the magnetic film material, the coercive force increases, but there is a problem that noise increases. On the other hand, when Ta or Ti is added to CoCrPt, the noise is reduced, but it is still not sufficient, and even if a magnetic head having a high-sensitivity magnetoresistive element is used in the reproducing section, even if the magnetic head has a high sensitivity per square inch. It is difficult to realize a recording density of 1 gigabit or more.

It is an object of the present invention to provide a magnetic storage device having a recording density of 1 gigabit per square inch or more, a high coercive force required to realize the magnetic storage device, and a 150 kFCI.
An object of the present invention is to provide an in-plane magnetic recording medium with low noise at the above recording density.

[0007]

According to the present invention, while utilizing the advantage of CoCrPt that the coercive force is increased, a new fourth element is added to the CoCrPt to achieve both the high coercive force and low noise. To achieve. In addition, by using a material having a lattice constant larger than that of conventional Cr for the base film, the coherence of the crystal with the magnetic film is improved, and the axis of easy magnetization of the magnetic film is oriented in-plane by using epitaxial growth. Let it. As a result, higher coercive force and lower noise are achieved.

That is, the in-plane magnetic recording medium of the present invention comprises:
A base film made of at least one element selected from the group consisting of V, Nb, Mo, Ta, W, and Ti on the substrate, or a base film made of V, Nb, Mo, Ta, W, and Ti with Cr A base film containing at least one selected element is provided, and at least Co, Cr, Pt, N
a magnetic film containing b.

The Cr concentration in the magnetic film is 16 at% or more and 25 at% or less, the Pt concentration is 6 at% or more and 24 at% or less, the Nb concentration is 0.5 at% or more and 6 at% or less. In addition, it is more preferable to use impurities that are inevitably included in the film formation process in terms of high coercive force and low noise. Nb added to the magnetic film promotes the segregation of Cr, and at the same time, segregates Nb itself, thereby weakening the interaction between magnetic particles and reducing noise. The addition of Nb also has the effect of reducing magnetic crystal grains. N added to the magnetic film
The reason that the b concentration is limited to 0.5 at% or more and 6 at% or less is that the effect is not so much seen at 0.5 at% or less, and that at 6 at% or more, the magnetic crystal grains become too small and the thermal stability becomes small. Is degraded (superparamagnetic material), or the crystal grains themselves become nonmagnetic, which is not preferable.

In an in-plane recording medium, it is preferable that the c-axis of magnetic crystal grains having a dense hexagonal lattice structure be in the film plane.
For this purpose, it is necessary to use a base film made of a body-centered cubic lattice, grow the (100) plane of the base film in parallel with the substrate, and epitaxially grow a magnetic film thereon. At this time, it is important to make the c-axis length of the magnetic film substantially equal to ａ2 times the a-axis length of the base film. Since Pt of 6 at% or more and 24 at% or less is added to the magnetic film, the c-axis length is much larger than that of pure Co. Therefore, in the conventional underlayer made of pure Cr, the lattice matching described above is deteriorated, and the component in which the c-axis of the magnetic film exists in the film plane decreases.

Therefore, in accordance with the size of the c-axis length of the magnetic film, the underlayer film includes at least one element selected from the group consisting of V, Nb, Mo, Ta, W, and Ti, or Cr.
In addition, it is necessary to use at least one element selected from the group consisting of V, Nb, Mo, Ta, W, and Ti.
The alloy of Cr and Mo is in a solid solution relationship even when viewed from the phase diagram of the bulk metal, and the crystal structure of the alloy is body-centered cubic, so a crystal with an arbitrary lattice size is produced. It is particularly preferable because it is easy to handle. Use of an alloy of Cr and Ti is particularly preferable in terms of noise reduction because crystal grains can be reduced. Cr, V, Nb, Mo, Ta, W
Has a body-centered cubic crystal structure, whereas Ti has a dense hexagonal crystal structure.
Ti must be less than 50 at% of the whole.

It is more preferable to provide an initial growth control film made of Cr between the non-magnetic substrate and the underlayer in order to enhance the in-plane orientation of the easy axis of the magnetic film. When a material other than Cr is used for the underlayer, crystallinity and orientation deteriorate.
Therefore, an initial growth control film made of Cr having excellent crystallinity and orientation is provided in advance, and V, Nb, Mo, T
a base film made of at least one element selected from the group consisting of a, W, and Ti;
By epitaxially growing a base film containing at least one element selected from the group consisting of o, Ta, W, and Ti, the (100) orientation of the base film can be increased. As a result, at the same time as the reproduced signal that has been magnetically recorded increases, the noise also decreases.

As described above, a medium using a CoCrNb magnetic film has been reported as a medium for perpendicular magnetic recording.
This medium uses Nb contained in the medium of the present invention. However, the role of Nb in both is completely different. That is, it has been reported that the addition of Nb improves the orientation of the axis of easy magnetization in the direction perpendicular to the film and increases the coercive force in the direction perpendicular to the film. On the other hand, in the medium of the present invention, the addition of Nb promotes the segregation of Cr, and at the same time, the medium noise is reduced by the segregation of Nb at the grain boundaries. This difference is caused by forming an appropriate underlayer in the present invention.
The c-axis of the magnetic film, which is the axis of easy magnetization, is oriented in the film plane, and it is known that the crystal orientation is completely different from that of the known example, or that a regular lattice with Co is formed in the magnetic film. It is considered to be due to the presence of the contained Pt.

The amount of Cr added to the magnetic film must be 16 at% or more and 25 at% or less. At 16 at% or less, the effect of reducing noise is small, and at 25 at% or more, the magnetic film becomes a non-magnetic material. Conventionally, it has been considered that when the amount of Cr added is increased to 16 at% or more as in the present invention, the residual magnetic flux density decreases, which is not preferable.
However, as a result of the present inventors using various magnetic heads to evaluate a medium having magnetic films with different Cr concentrations, when a highly sensitive magnetoresistive head (MR head) is used, It became clear that the effect of noise reduction was maximized by adding Cr of 16a to 25t%, and excellent characteristics were exhibited.

The problem of a decrease in the residual magnetic flux density due to an increase in the Cr concentration can be overcome by increasing the sensitivity of the head because a high output can be obtained even with a small residual magnetic flux density. Further, by strongly orienting the easy axis of magnetization of the magnetic film in the film plane, a higher output can be obtained and the medium S / N can be improved. The in-plane orientation of the easy axis can be further enhanced by providing an initial growth control film made of Cr. Further, the fact that the amount of Pt added to the magnetic film is 6 at% or more and 24 at% or less as compared with a normal medium is also considered to contribute to the expansion of the allowable limit of the addition of Cr.

At the time of recording, the residual magnetic flux density (Br) and the thickness of the magnetic film (tmag) measured by applying a magnetic field in the direction of travel of the magnetic head relative to the in-plane magnetic recording medium are measured.
(Br · tmag) is 10G · μm or more and 130G
When the coercive force measured in the same direction as the magnetic field application direction is 1.8 kOe or more, the magnetization transition region at the time of recording is narrowed, which is more preferable in terms of low noise.

Further, the in-plane magnetic recording medium of the present invention,
A drive unit for driving the longitudinal magnetic recording medium in the recording direction, a magnetic head including a recording unit and a reproducing unit, means for moving the magnetic head relative to the longitudinal magnetic recording medium, and an input signal to the magnetic head And a recording / reproducing signal processing means for performing waveform processing on an output signal, wherein the reproducing section of the magnetic head is constituted by a magnetoresistive element so that a recording density of 1 gigabit or more per square inch can be achieved. And a magnetic storage device having the same.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. [Embodiment 1] FIG. 1 is a sectional view showing an example of a longitudinal magnetic recording medium according to the present invention. Hereinafter, a method for manufacturing the in-plane magnetic recording medium whose sectional view is shown in FIG. 1 will be described.

Ni-P plated Al having an outer diameter of 95 mmφ
After subjecting the Mg alloy substrate 11 to substrate etching for 10 seconds at an input power of RF 30 W, the substrate temperature was set to 300 ° C., and Ar
Gas pressure 2.5 mTorr, input power density 5 W / cm ²
Under the film forming conditions, Cr-20 at% Mo was used as the underlayers 12 and 12 ′ by DC magnetron sputtering.
0 nm was formed. Then, under the same film forming conditions, the magnetic film 1
A 15 nm thick CoCrPtNb alloy was formed as 3,13 '. Finally, a substrate temperature of 150 ° C. and an Ar gas pressure of 5 mT
orr, under the film forming condition of the input power density of 3 W / cm ² ,
C was formed to a thickness of 10 nm as the protective films 14 and 14 '. Here, the numbers before the elements indicate the concentration of each element.

First, the CoC of the magnetic films 13, 13 'is used.
The composition of the rPtNb alloy was studied. Using Co-20 at% Cr-12 at% Pt as the base magnetic film, Nb was changed in the range of 0 to 10 at%, and the Nb concentration dependency was examined. Nb addition concentration and coercive force Hc
2 is shown in FIG. 2, and the relationship with the medium S / N is shown in FIG. Here, the medium S / N is a value obtained by dividing a reproduction output at the time of recording at a recording density of 160 kFCI by a medium noise at that time and displaying the result in dB. At this time, if a medium S / N of 20 dB or more is obtained, a recording density of 1 gigabit per square inch can be achieved.

From FIG. 2, it can be seen that the coercive force gradually decreases while adding Nb of 6 at% or less while maintaining 3.0 kOe or more.
It can be seen that the coercive force sharply decreases at an addition concentration exceeding 6 at%. In addition, the medium S / N shown in FIG.
The maximum is obtained by adding ３3 at% of Nb. From this result, the Nb addition amount was 0.5 at% or more and 6 at% or more.
It became clear that it was necessary to:

Next, the relationship between the amount of Pt, the coercive force and the medium S / N is shown in FIGS. Co-21 at% for the magnetic film
The composition was examined by changing the amount of Pt using Cr-2.5 at% Nb as a base. At this time, a Cr-V alloy was used for the underlayer, and the V concentration was changed in accordance with the amount of Pt so that the c-axis length of the magnetic film was approximately equal to ａ2 times the a-axis length of the underlayer. . The maximum coercive force is obtained with a Pt amount of 16 to 18 at%. In this connection, the medium S / N is likewise 16 to 18
The maximum is obtained with an at% Pt amount. To achieve a recording density of at least 1 gigabit per square inch,
Coercive force of 1.8 kOe or more and medium S / N of 20 dB or more
Therefore, it is necessary to add Pt in the range of 6 to 24 at%. If the amount of Pt is increased, the cost will increase.
The amount may be adjusted.

As in the above study, Co-15 at% Pt-4 at% Nb was used for the base magnetic film,
As a result of adding r at different concentrations, the medium S
In order to satisfy the condition of / N, it was found that it was preferable to satisfy 16 ≦ Cr ≦ 25 (FIG. 6). 16at
%, The effect of reducing the medium noise due to the segregation of Cr at the grain boundaries cannot be obtained so much. On the other hand, when the content was 25 at% or more, it was found that the magnetic film itself became a non-magnetic material, which was not preferable as an in-plane magnetic recording medium.

From the above results, in any case, CoC
It was found that a recording density of at least 1 gigabit per square inch can be achieved by adding Nb in the range of 0.5 at% to 6 at% to the rPt magnetic film. At the same time, the Pt addition amount is 6 to 24a.
t in the range of 16% to 25 at.
%.

Co-20 at% Cr-12 at% Pt-
In the medium having the structure shown in FIG. 1 using a 2 at% Nb magnetic film, when the underlayers 12 and 12 'are changed from CrMo to pure Cr, as shown in Table 1 below, the characteristics are improved as in the medium of the present invention. No effect was observed. This is because the in-plane orientation of the c-axis, which is the axis of easy magnetization of the magnetic film, deteriorated. Further, a Cr film is formed between the substrate 11 and the base films 12 and 12 '.
When the initial growth control film made of
The coercive force and medium S / N were further improved, albeit slightly, as shown in FIG. This is because C is between the substrate and the CrMo underlayer.
This is because the provision of the initial growth control film made of r improves the orientation of the easy axis of the magnetic film in the plane. This property is not only effective when the underlayer is made of CrMo, but the underlayer made of an alloy of at least two or more elements selected from the group consisting of Cr, V, Nb, Mo, Ta, W, and Ti. It was confirmed that it always holds when used.

[0026]

[Table 1]

[0027]

[Table 2]

By changing the thickness of the magnetic film, the product of the residual magnetic flux density (Br) and the thickness of the magnetic film (tmag) (Br ·
tmag). The results are shown in FIGS. Br · tmag measured by applying a magnetic field in the direction of travel of the magnetic head relative to the longitudinal magnetic recording medium during recording is 10 G · μm or more and 130 G · μm or more.
It turns out that it is necessary to: This is 130
If the thickness is not less than G · μm, the medium noise increases, which is not preferable. If the thickness is not more than 10 G · μm, the output cannot be obtained, and at the same time, the thermal fluctuation of magnetization is large and the recording bit may be lost. is there. At this time, the coercive force was required to be 1.8 kOe or more. If this condition was not satisfied, a sufficient output could not be obtained when recording a signal of 150 kFCI or more.

[Second Embodiment] The in-plane magnetic recording medium of the first embodiment employs a magnetic head provided with a read-only sensor utilizing the magnetoresistance effect as shown in FIG. The performance is fully utilized. The recording magnetic head is an inductive type thin film magnetic head including a pair of recording magnetic poles 91 and 92 and a coil 93 linked to the recording magnetic poles 91 and 92.
The thickness of the gap layer between the recording magnetic poles was 0.3 μm. Also,
The magnetic pole 92 is paired with a magnetic shield layer 96 having a thickness of 1 μm, and also serves as a magnetic shield for a reproducing magnetic head.
This shield interlayer distance is 0.25 μm. The read-only magnetic head is a magneto-resistance effect type head including a magneto-resistance effect sensor 94 and a conductor layer 95 serving as an electrode. This magnetic head is provided on a magnetic head slider base 97. In FIG. 3, the gap layer between the recording magnetic poles and the gap layer between the shield layer and the magnetoresistive sensor are omitted.

FIG. 10 shows a detailed sectional structure of the magnetoresistive sensor 95. The signal detection area 101 of the magnetic sensor is
A lateral bias layer 103 on the gap layer 102 of Al oxide;
The separation layer 104 and the magnetoresistive ferromagnetic layer 105 are formed in this order. The magnetoresistive ferromagnetic layer 105 has 20n
m of NiFe alloy was used. The lateral bias layer 103 has 2
Although 5 nm of NiFeNb was used, any ferromagnetic alloy such as NiFeRh having relatively high electric resistance and good soft magnetic properties may be used. The lateral bias layer 103 is a magnetoresistive ferromagnetic layer 1
Due to the magnetic field induced by the sense current flowing through the layer 05, the film is magnetized in the in-plane direction (lateral direction) perpendicular to the current, and a lateral bias magnetic field is applied to the magnetoresistive ferromagnetic layer 105. Thereby, the magnetic sensor can obtain a linear reproduction output with respect to the leakage magnetic field from the medium. The separation layer 104 for preventing the shunt of the sense current from the magnetoresistive ferromagnetic layer 105 was made of Ta having a relatively high electric resistance and had a thickness of 5 nm. At both ends of the signal detection region 101, there are tapered portions 106 processed into a tapered shape. Tapered part 106
Comprises a permanent magnet layer 107 for converting the magnetoresistive ferromagnetic layer 105 into a single magnetic domain, and a pair of electrodes 108 formed thereon for extracting signals. It is important that the permanent magnet layer 107 has a high coercive force and the magnetization direction does not easily change, and CoCr, CoCrPt alloy or the like is used.

The magnetoresistive sensor 95 has a structure shown in FIG.
It is preferable to use a spin valve type as shown in FIG. 1 because a larger output can be obtained. The signal detection region 111 of the magnetic sensor includes a Ta buffer layer 113 of 5 nm, a first magnetic layer 114 of 7 nm on the gap layer 112 of Al oxide,
This is a structure in which a 1.5-nm Cu intermediate layer 115, a 3-nm second magnetic layer 116, and a 10-nm Fe-50 at% Mn antiferromagnetic alloy layer 117 are sequentially formed. First magnetic layer 1
For Ni, an Ni-20 at% Fe alloy was used, and for the second magnetic layer 116, Co was used. The magnetization of the second magnetic layer 116 is fixed in one direction by the exchange magnetic field from the antiferromagnetic alloy layer 117. On the other hand, the first magnetic layer 11 in contact with the second magnetic layer 116 via the non-magnetic intermediate layer 115
The direction of magnetization 4 changes due to the leakage magnetic field from the longitudinal magnetic recording medium. The change in the relative directions of the magnetizations of the two magnetic layers causes a change in the resistance of the entire three films. This phenomenon is called a spin valve effect. In the present embodiment, a spin valve magnetic head utilizing this effect is used for the magnetoresistive sensor. The tapered portion 118 including the permanent magnet layer 119 and the electrode 120 is the same as that of the normal magnetoresistive sensor shown in FIG.

FIG. 12 is a top view of an example of the magnetic storage device.
FIG. 12A schematically shows a cross-sectional view taken along the line AA ′ of FIG. The in-plane magnetic recording medium 121 is held by a holder connected to the in-plane magnetic recording medium driving unit 122, and a magnetic head 123 schematically illustrated in FIG. 9 is opposed to each surface of the in-plane magnetic recording medium 121. Be placed. Magnetic head 123
Is driven by the magnetic head drive unit 125 to a desired track with a head positioning accuracy of 0.5 μm or less with a flying height of 0.06 μm or less.

The signal reproduced by the magnetic head 123 is subjected to waveform processing by a recording / reproducing signal processing system 124. The recording / reproducing signal processing system 124 includes an amplifier, an analog equalizer, an AD converter, a digital equalizer, a maximum likelihood decoder, and the like. The reproduced waveform of the head using the magnetoresistive effect is different from the recorded signal because the positive and negative magnitudes are asymmetric due to the characteristics of the head and are affected by the frequency characteristics of the recording / reproducing system. May be misread. The analog equalizer has a function of adjusting a reproduced waveform and restoring the waveform. The restored waveform is converted into a digital signal through an AD converter, and the waveform is further adjusted by a digital equalizer. Finally, the restored signal is demodulated by a maximum likelihood decoder into the most likely data. With the reproduction signal processing system having the above configuration, recording and reproduction of signals are performed at an extremely low error rate. Note that existing equalizers and maximum likelihood decoders may be used.

With the above-described device configuration, the recording density per square inch can correspond to 1 gigabit or more, and the high-density magnetic storage having a storage capacity three times or more as compared with the conventional magnetic storage device. The device could be realized. Further, even when the maximum likelihood decoder is removed from the recording / reproducing signal processing system and replaced with a conventional waveform discrimination circuit, a magnetic storage device having a storage capacity twice or more as compared with the conventional one can be realized.

In the above embodiments, examples of a disk-shaped in-plane magnetic recording medium and a magnetic storage device using the same have been described. However, the present invention relates to a tape-shaped or card-shaped magnetic recording medium having a magnetic layer only on one side. It goes without saying that the present invention can be applied to a magnetic recording medium and a magnetic storage device using the magnetic recording medium. Further, regarding the method of manufacturing the magnetic recording medium, D
Not limited to the C magnetron sputtering method, any method such as an ECR sputtering method, an ion beam sputtering method, a vacuum evaporation method, a plasma CVD method, a coating method, and a plating method may be used.

[0036]

According to the longitudinal magnetic recording medium of the present invention, the coercive force is high, and low noise at a recording density of 150 kFCI or more can be realized. Further, by combining this in-plane magnetic recording medium with a magnetic head having a read-only element utilizing the magnetoresistance effect, a magnetic storage device having a recording density of 1 gigabit per square inch or more can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an example of a longitudinal magnetic recording medium according to the present invention.

FIG. 2 is a diagram showing a relationship between Nb addition concentration and coercive force.

FIG. 3 is a diagram showing the relationship between the Nb addition concentration and the medium S / N.

FIG. 4 is a diagram showing a relationship between a Pt addition concentration and a coercive force.

FIG. 5 is a diagram showing a relationship between Pt addition concentration and medium S / N.

FIG. 6 is a diagram showing the relationship between the Cr addition concentration and the medium S / N.

FIG. 7 is a diagram showing the relationship between Br · tmag and coercive force.

FIG. 8 is a diagram showing a relationship between Br · tmag and a medium S / N.

FIG. 9 is a schematic diagram showing an example of the structure of a magnetic head including an element utilizing the magnetoresistance effect.

FIG. 10 is a structural diagram showing an example of a magnetoresistive sensor.

FIG. 11 is a structural diagram showing an example of a spin-valve magnetoresistive sensor.

FIG. 12 is a schematic view illustrating an example of the structure of a magnetic storage device.

[Explanation of symbols]

Record 11: substrate, 12, 12 ': base film, 13, 13'
... magnetic film, 14, 14 '... protective film, 91 ... recording magnetic pole, 9
2: magnetic pole and magnetic shield layer, 93: coil, 94: magnetoresistive element, 95: conductor layer, 96: magnetic shield layer,
97: slider base, 101: signal detection area of magnetic sensor, 102: gap layer, 103: lateral bias layer, 10
4 ... Separation layer, 105 ... Magnetoresistance ferromagnetic layer, 106 ... Tapered portion, 107 ... Permanent magnet layer, 108 ... Electrode, 111 ...
Signal detection area of magnetic sensor, 112... Gap layer, 11
3 buffer layer 114 114 first magnetic layer 115 intermediate layer 116 second magnetic layer 117 antiferromagnetic alloy layer
Reference numeral 118: tapered portion, 119: permanent magnet layer, 120: electrode, 121: in-plane magnetic recording medium, 122: magnetic recording medium driving unit, 123: magnetic head, 124: recording / reproducing signal processing system, 125: magnetic head driving unit

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kaoru Tanahashi 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Inside the Hitachi, Ltd. Central Research Laboratory (72) Inventor Tetsuya Kanbe 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Hitachi, Ltd. Central Research Laboratory (72) Inventor Joe Hosoe 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Inside Central Research Laboratory, Hitachi, Ltd.

Claims (6)

[Claims] 1. V, Nb, Mo, Ta, W, T
i, a base film made of at least one element selected from the group consisting of i, or V, Nb, Mo, Ta,
A base film containing at least one element selected from the group consisting of W and Ti is provided, and at least Co, C
An in-plane magnetic recording medium provided with a magnetic film containing r, Pt, and Nb. 2. The magnetic film according to claim 1, wherein a Cr concentration is 16 at% or more and 25 at% or less, and a Pt concentration is 6 at% or more and 24 at%.
2. The longitudinal magnetic recording medium according to claim 1, wherein the Nb concentration is 0.5 at% or more and 6 at% or less. 3. An initial growth control film made of Cr is provided on a substrate, and a base film made of at least one element selected from the group consisting of V, Nb, Mo, Ta, W, and Ti, or , Cr with V, Nb, Mo, Ta, W, T
forming an underlayer containing at least one element selected from the group consisting of i, and forming at least Co, Cr,
An in-plane magnetic recording medium provided with a magnetic film containing Pt and Nb. 4. The magnetic film has a Cr concentration of 16 at% or more and 25 at% or less, and a Pt concentration of 6 at% or more and 24 at%.
4. The longitudinal magnetic recording medium according to claim 3, wherein the Nb concentration is 0.5 at% or more and 6 at% or less. 5. The product of the residual magnetic flux density measured by applying a magnetic field in the direction of travel of the magnetic head relative to the longitudinal magnetic recording medium during recording and the film thickness of the magnetic film is 10 G · μm.
5. The longitudinal magnetic recording according to claim 1, wherein the coercive force measured in the same direction as the direction in which the magnetic field is applied is 1.8 kOe or more. Medium. 6. A longitudinal magnetic recording medium, a driving unit for driving the longitudinal magnetic recording medium in a recording direction, a magnetic head including a recording unit and a reproducing unit, and the magnetic head being attached to the longitudinal magnetic recording medium. 6. A magnetic storage device comprising: means for moving relative to the magnetic head; and recording / reproducing signal processing means for performing waveform processing on an input signal and an output signal to the magnetic head, wherein the longitudinal magnetic recording medium is any one of claims 1 to 5. A magnetic storage device comprising the longitudinal magnetic recording medium according to claim 1, wherein a reproducing unit of the magnetic head includes a magnetoresistive element.