JPH05266456A - Magnetic recording medium and magnetic recorder - Google Patents

Abstract

PURPOSE:To provide a magnetic recording medium capable of high density recording by forming a magnetic film on a substrate with primary grains having axes of easy magnetization in a direction parallel to the surface of the substrate and secondary grains having axis of easy magnetization in a direction perpendicular to the surface of the substrate and regulating the ratio of the primary grains to the secondary grains in the magnetic film to 1-20. CONSTITUTION:Plating films 12, 12' of Ni-P are formed on both sides of a discoid substrate 11 of Al-Mg. The surfaces of the plating films 12, 12' are made flat by polishing in practically circumferential directions and fine ruggedness having prescribed center line average roughness (nm) is formed so as to inhibit sticking to a magnetic head. The substrate 11 is then put in a magnetron sputtering device, where Cr underlayers 13, 13' are formed in various thicknesses after firing at a prescribed temp., magnetic metal films 14, 14' of Co-12Cr-3Ta are formed on the underlayers 13, 13' and protective films 15, 15' of carbon are further formed on the films 14, 14'. The ratio of primary grains having axes of easy magnetization in a direction parallel to the surface of the substrate 11 to secondary grains having the axis of easy magnetization in a direction perpendicular to the surface of the substrate 11 in the magnetic metal film 14 is regulated to 1-20.

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 recording device, and more particularly to a thin film type recording medium suitable for high density magnetic recording and a magnetic recording device using the same.

[0002]

2. Description of the Related Art In recent years, with the downsizing and speeding up of electronic computers, there has been a strong demand for magnetic disks and other external storage devices to have a large capacity and high speed access. In particular, the magnetic disk recording device is an information storage device suitable for high-density and high-speed recording, and its demand is further increasing. The magnetic recording medium used in the magnetic disk device includes a coating type recording medium formed by coating powder of an oxide magnetic material on a disk substrate, and a method of sputtering a thin film of a metal magnetic material on the substrate. A thin film type recording medium formed by vapor deposition is known. The thin film type recording medium is suitable for high density recording because the magnetic substance density in the recording film is higher than that of the coating type recording medium.

A Co-based alloy having a large crystal magnetic anisotropy is mainly used as a magnetic material of the thin film type recording medium. Co-based alloys are hexagonal close-packed (hexagonal)
close-packed: hereinafter abbreviated as hcp)
And has an easy magnetization direction parallel to the c-axis of the hcp structure, and has a high coercive force Hc, remanent magnetization Br, and squareness ratios S and S * in this direction. In the current magnetic disk device, the direction of magnetization recorded as information in the medium is substantially parallel to the substrate surface. Therefore, when forming the medium, the c-axis of the Co-based alloy is substantially parallel to the substrate surface. It is necessary to grow the crystals so that they are parallel to each other.

For this purpose, in many cases, a body-centered cubic structure (body-centered structure) is used as an underlying film of a magnetic film.
There is known a method of controlling the crystal orientation of a Co-based alloy by forming a Cr or Cr-based alloy film having a cubic (hereinafter abbreviated as bcc). For example, in JP-A-1-220217, the (100) crystal lattice plane of Cr is parallel to the substrate surface, and the film thickness is 5 nm to 20 n.
A magnetic recording medium is disclosed in which a (110) crystal lattice plane of a Co-based alloy and a c-axis are formed parallel to a substrate surface on a Cr underlayer of m. Further, in Japanese Patent Laid-Open No. 62-257618, by adding V or Fe to the Cr underlayer, the size of the crystal lattice of the bcc structure is increased, and the Cr (1
There is disclosed a magnetic recording medium having improved coercive force and squareness by improving the matching between the (00) crystal lattice plane and the (110) crystal lattice plane of a Co-based alloy. Furthermore, JP-A-63-197
No. 018 shows a magnetic recording medium in which Ti or Si is added to a Cr underlayer so that the crystal orientation of the Cr underlayer is isotropic in the disk plane and the modulation is reduced.

[0005]

As described above, thin film type recording media using various underlayer films have been proposed in the past, but these mainly improve the magnetostatic characteristics such as coercive force and squareness ratio. However, the dynamic magnetic recording characteristics such as noise during recording, reproduction output, and resolution have not been studied in detail. For this reason, the conventional thin film type recording medium has insufficient S / N and resolution at the time of recording / reproducing, and in order to improve the performance of the magnetic disk device, it is strongly required to develop a magnetic recording medium having more excellent characteristics. It was wanted. Further, when recording / reproducing is performed using a recording / reproducing type head that uses a magnetoresistive type (hereinafter abbreviated as MR) head having excellent reproducing sensitivity, it is possible to significantly reduce the noise of the medium as compared with the conventional case. It was wanted.

In view of the above problems and circumstances, the first object of the present invention is to provide a magnetic recording medium having an output half recording density D ₅₀ of 30 kFCI or more and a medium S / N value of 3 or more, which enables high density recording. The second purpose is to provide a method for producing such a medium with good reproducibility, and the third purpose is to provide a large capacity and high reliability using such medium. A magnetic recording device is provided.

[0007]

[Means for Solving the Problems] The inventors of the present invention have investigated the crystal structures of the base film and the magnetic layer, noise during recording and reproduction, reproduction output,
As a result of intensive studies on the relationship with the dynamic magnetic characteristics such as resolution, the above-mentioned object was to use a Co-based alloy film as the magnetic layer and Cr, Mo, W, V, Nb and T as the underlayer film.
In a thin film magnetic recording medium containing as a main component at least one metal element selected from the first group consisting of a, crystal grains having a c-axis of an hcp structure, that is, an easy axis of magnetization in a direction substantially parallel to the substrate surface. (Hereinafter, abbreviated as substantially in-plane crystal grains) and crystal grains having an easy axis of magnetization in a direction substantially perpendicular to the substrate surface (hereinafter abbreviated as substantially vertical crystal grains)
It was found that both of the above can be achieved by forming a magnetic recording medium having a magnetic film mixed with a certain ratio with good reproducibility. This can be expressed by the value of L / P when the contents of the substantially in-plane crystal grains and the substantially vertical crystal grains in the magnetic film are defined as L and P, respectively. This is when the value of L / P is 1 or more and 20 or less. Here, in the Co-based alloy having the hcp structure, the substantially in-plane crystal grains correspond to the crystal grains whose crystal lattice planes substantially parallel to the substrate surface are (100), (101), and (110) planes. The substantially vertical crystal grain corresponds to the crystal grain whose crystal lattice plane substantially parallel to the substrate surface is the (001) plane.

Further, through extensive research up to the present invention, a preferable crystal orientation was realized in the magnetic film and the above L
In order to set the value of / S to a desired value with good reproducibility, it has been clarified that it is effective to optimize the structure, crystal orientation and composition of the substrate and the underlying film, and epitaxially grow the magnetic film on this. We have found that the following three methods work.

In the first method, a non-magnetic metal underlayer film containing at least one element selected from the above-mentioned first group as a main component is formed so as to cover the entire portion of the substrate where the nonmagnetic metal underlayer film is to be formed. 1% of planned area
This is a method in which the substrate surface is exposed by an area of 30% or less. Further, it is preferable that the crystal grain sizes of the non-magnetic metal underlayer film are separated from each other by a size of 1 nm or more and less than 50 nm in order to enable high-density recording / reproduction. Furthermore, it is preferable that the crystal grains of the nonmagnetic metal underlayer have a body-centered cubic lattice type crystal structure in order to enable high-density recording / reproduction. In order to form the non-magnetic metal underlayer having the above structure, it is necessary to optimize the conditions for forming the nonmagnetic metal underlayer, for example, the argon pressure, the substrate temperature, the film thickness, and the film formation rate. It is preferably 5 nm or more and less than 50 nm.

In the second method, as a material for the non-magnetic metal underlayer, at least one element selected from the first group is contained as a main component, and Ti, Zr, Sc,
Y, Hf, Rh, Os, Zn, Cd, La, Ce, P
r, Nd, Ir, Pt, Au, Pd, Ag, Cu, T
The main crystal grains in the underlayer are made of a material to which at least one element selected from the second group consisting of 1, Si, Ge, Sn, Pb, and P is added at a concentration of 1 atomic% or more and 30 atomic% or less. Has a bcc type crystal structure and has a structure in which at least one element selected from the second group is segregated in the crystal grains and / or at the crystal grain boundaries.

In the third method, first, a crystal orientation control film containing at least one element selected from the second group as a main component is formed on a non-magnetic disk substrate, and then this crystal orientation control film is formed. A nonmagnetic metal underlayer film containing at least one element selected from the first group as a main component is formed on the control film so as to cover the entire nonmagnetic metal underlayer film formation planned portion of the crystal orientation control film. Instead of this, it is a method in which the surface of the crystal orientation control film is exposed in an area of 1% or more and 30% or less of the area to be formed.

A Co-based alloy magnetic film having a film thickness of 10 to 100 nm is formed on a non-magnetic metal base film, a carbon film having a film thickness of 10 to 50 nm is formed as a protective film, and an adsorbent lubricant such as perfluoroalkyl polyether is formed. The film thickness of 1 to 20 nm
When formed, a magnetic recording medium capable of high density recording can be obtained. Further, as a magnetic film, Cr, Mo, W, Zr,
It is preferable to use an alloy containing at least one element selected from Ta, Nb, Al, Si, and Pt because the recording / reproducing characteristics and corrosion resistance of the medium are improved. In particular, the magnetic substance forming the magnetic film is CoNi, CoCr, CoFe, Co.
Good recording / reproducing characteristics can be obtained when the alloy is Mo, CoW, CoPt, CoRe, or the like. In addition, when particularly good corrosion resistance and recording / reproducing characteristics are required, CoNiZr, CoCrPt, Co are used as the magnetic material forming the magnetic film.
An alloy containing CrTa or CoNiCr as a main component is preferable. In addition, as a protective film, carbides such as WC and WMoC,
It is preferable to use a nitride such as ZrNbN, Si ₃ N ₄ or the like, an oxide such as SiO ₂ , ZrO ₂ or B, B ₄ C, MoS ₂ , Rh or the like because the sliding resistance and the corrosion resistance are improved. The disk substrate can use Al-Mg alloy, chemically strengthened glass, or organic resin, and non-magnetic plating made of Ni-P, Ni-WP, Ni-V, etc. on these substrates. It is also possible to use a film or alumite-treated film having a surface-hardened or polished film formed thereon. Furthermore, by combining the above magnetic recording medium with a magnetic head having a track width of 10 μm or less, it is possible to provide a magnetic recording device having a large capacity and high reliability.

[0013]

As a result of the experiment, by forming the magnetic film so that the L / P value is 1 or more and 20 or less, the output half recording density D ₅₀ is 30 kFCI or more and the medium S / N value is 3 or more. It was found that the object of the present invention can be achieved.

The reason for this is considered as follows. As in the conventional case, when a magnetic crystal is formed as the magnetic layer so that the easy axis of magnetization is substantially parallel to the substrate surface, a high reproduction output can be obtained. In the transition region, the magnetizations with different directions cause strong repulsion, and the demagnetizing field component increases. As a result, the magnitude of the magnetization and the fluctuation in the direction become large, and the medium noise becomes large when recording at a high density and D _50.
And the S / N ratio decreases. On the other hand, when a magnetic film structure in which substantially in-plane crystal grains and substantially perpendicular crystal grains are mixed as in the present invention, the magnetization direction becomes substantially perpendicular at the recording bit boundary, and the repulsion of magnetization becomes substantially perpendicular. escape. As a result, the fluctuation of the magnetization becomes small, medium noise is reduced when recording at high density, D ₅₀ and the medium S / N
The ratio is improved.

In the first method for optimizing the L / S value, the crystal of the magnetic film is epitaxially grown on the crystal lattice of the nonmagnetic metal underlayer on the nonmagnetic metal underlayer, so that the magnetization of the magnetic film is easy. The direction is substantially parallel to the substrate surface, and the magnetic film crystal has the property of growing in a crystal orientation such that the c-axis is substantially perpendicular to the substrate surface in the portion where the non-magnetic metal underlayer is not present. The easy magnetization direction is substantially perpendicular to the substrate surface. As a result, a magnetic film in which substantially parallel crystal grains and substantially vertical crystal grains are mixed can be formed. further,
By forming the non-magnetic metal underlayer having the structure according to this method, the contact area between the medium and the magnetic head is reduced as compared with the case where a continuous non-magnetic metal underlayer is used. It also has the effect of improving sliding resistance and increasing reliability. In the second method of optimizing the value of L / S,
The magnetic film crystal grows epitaxially on the crystal lattice of the non-magnetic metal underlayer on the crystal grain, and the easy magnetization direction of the magnetic film is substantially parallel to the substrate surface, but on the crystal grain boundary, the magnetic film crystal is c-axis. Has a property of being oriented and grown so as to be substantially perpendicular to the substrate surface, so that the easy magnetization direction of the magnetic film is substantially perpendicular to the substrate surface. As a result, a magnetic film in which substantially parallel crystal grains and substantially vertical crystal grains are mixed can be formed.

In the third method of optimizing the value of L / S, the magnetic film crystal is epitaxially grown on the crystal lattice of the nonmagnetic metal underlayer on the nonmagnetic metal underlayer, and the easy magnetization direction of the magnetic film is the substrate. Although it is substantially parallel to the plane, since the magnetic film crystal has the property of growing on the crystal orientation control film so that the c-axis is substantially perpendicular to the substrate surface, the easy direction of magnetization of the magnetic film is the substrate. Substantially perpendicular to the plane. as a result,
It is possible to form a magnetic film in which substantially parallel crystal grains and substantially vertical crystal grains are mixed. Further, by forming the crystal orientation control film, the film strength of the medium is increased as compared with the case of using only the non-magnetic metal underlayer, so that the sliding resistance when the magnetic head comes into contact is improved and the reliability is increased. There is also an effect.

The above-mentioned effects due to the structure of the non-magnetic metal underlayer film and the crystal orientation control film are obtained by using CoCrPt or CoCr as the magnetic film.
Not only Ta but also Ni, Ti, Zr, Hf, T in addition to Co
It is also recognized for alloys containing at least one element selected from a, Pt, Nb, Cr, Mo, W, Si and Ge.

In the medium according to the present invention, the fluctuation of the magnetization in the magnetization transition region is extremely small, so that the medium noise is small and the S / N at the high recording density of 50 kBPI or more when recording with the magnetic head having the track width of 10 μm or less. Of 3 or more, and a large-capacity magnetic recording device having an overwrite (O / W) characteristic of 26 dB or more can be obtained.

[0019]

EXAMPLES The present invention will be described in more detail below with reference to examples. 1, FIG. 2 and FIG. 3 schematically show the cross-sectional structure of the thin film magnetic recording medium according to the present invention. In the figure, 11 is a magnetic disk substrate made of Al-Mg alloy or chemically strengthened glass, organic resin, Ti, carbon, ceramics, etc., 12 and 12 'are Ni-P and Ni-W- formed on both sides of the substrate 11. It is a non-magnetic plating film made of P or the like. When an Al-Mg alloy is used as the substrate, one having such a plating film is usually used as the substrate of the magnetic disk. 13 and 13 'are base films formed on the plated films 12 and 12' and containing at least one element selected from the above-mentioned first group as a main component.
And 14 'are CoNi and C formed on the underlying film.
oCr, CoRe, CoPt, CoP, CoFe, Co
NiZr, CoCrAl, CoCrTa, CoCrP
t, CoNiCr, CoCrNb, CoNiP, CoN
Magnetic films made of iPt, CoCrSi, etc., 15 and 1
5'is carbon, boron, B formed on the magnetic film
₄ C, SiC, SiO ₂ , Si ₃ N ₄ , WC, WMoC, W
A non-magnetic protective film made of ZrC or the like, 16 and 16 'are components segregated in the base film with at least one element selected from the second group as a main component, and 17 and 17' are plated films 12 and 12 And a crystal orientation control film mainly composed of at least one element selected from the above-mentioned second group, which is formed on the above.

Example 1 An example of a thin film type recording medium will be described with reference to FIG. Outer diameter 130mm, inner diameter 40mm, thickness 1.9mm, Al-
Disk substrate 11 made of 4Mg (the number before the atomic symbol indicates the content of the material, in this case, wt%)
On both sides of the film made of Ni-12P (% by weight) 13 μm
Plating films 12 and 12 ′ were formed. The surface of the Ni-P plated film is polished substantially in the circumferential direction (head traveling direction) to flatten the surface, and at the same time, fine irregularities having a center line average surface roughness of 5 to 10 nm are provided for the purpose of suppressing adhesion of the magnetic head. Was formed (such a surface processing is hereinafter abbreviated as texturing). Next, the disk substrate was loaded into a magnetron sputtering device and kept at a temperature of 200 ° C. for 5 m.
Under the Ar pressure of Torr, the Cr underlayer 13,
13 'was formed with various film thicknesses (Sample Nos. 1 to 8, Comparative Example: No substrate exposed). Co-12C on top of this base film
Metal magnetic films 14, 14 'made of r-3Ta (atomic%)
To a thickness of 40 nm. After that, the film thickness of 20 on the magnetic film
nm carbon protective films 15 and 15 'were formed. Finally, a lubricating film (not shown) such as an adsorbent perfluoroalkylpolyether was formed on the protective film to manufacture a thin film type recording medium.

In producing the magnetic recording medium, the shape of the cross section and the surface is a scanning electron microscope (hereinafter abbreviated as SEM), a transmission electron microscope (hereinafter abbreviated as TEM), or a scanning tunneling microscope (hereinafter abbreviated as STM). , The ratio of the area where the substrate is exposed to the area of the base film S
I asked. Further, the crystal orientation of the magnetic film was examined by X-ray diffraction and electron beam diffraction methods, and the contents L and P of substantially parallel crystal grains and substantially vertical crystal grains were obtained. In addition, the coercive force in the in-plane direction of the medium sample was measured by VSM. Furthermore, the recording / reproducing characteristics of the medium were set to a relative speed of 12 m / s and a floating spacing of 0.
At 08 μm, an output half recording density (D ₅₀ ) and medium S / N were obtained using a thin film magnetic head having an effective gap length of 0.4 μm and a track width of 10 μm. The results are shown in Table 1.

[0022]

[Table 1]

As shown in Table 1, the exposed area ratio S of the substrate changed depending on the film thickness of the Cr underlayer, and the coercive force, the output half recording density D ₅₀ and the medium S / N also changed accordingly. In particular, when the S value is 1% or more and 30% or less, the output half recording density of 30 kFCI or more, which is the object of the present invention, and 3
A medium having the above medium S / N was obtained. L at that time
The value of / P was in the range of 1 or more and 20 or less. Also,
When the Cr underlayer thickness is 0.5 nm or more and less than 10 nm, C
The crystal grain size of the r base film was 1 nm or more and less than 50 nm, and the structures were separated from each other. Also,
It was confirmed by X-ray diffraction that the main crystal structure in the base film was the bcc type. Further, the same effect was observed when an underlayer film containing any of Mo, W, V, Nb, and Ta as a main component was used instead of Cr as the underlayer film.

Embodiment 2 Another embodiment of the thin film type recording medium will be described with reference to FIG. The same disk substrates 11, 12 and 12 'as in Example 1 were loaded in a magnetron sputtering apparatus, kept at a temperature of 200 ° C., and under the condition of an argon pressure of 2 mTorr, Cr, Ti, Zr, Sc, Y, Hf, Rh, Os, Z
n, Cd, La, Ce, Pr, Nd, Ir, Pt, A
u, Pd, Ag, Cu, Tl, Si, Ge, Sn, P
Underlayer films 13 and 13 'containing any one element of the second group consisting of b and P were formed to a film thickness of 100 nm (Sample No. 9).
~ 33, comparative example: no addition). At that time, by controlling the addition amount of the element in the second group, the substrate heating time, and the film formation rate, the crystal grains mainly containing Cr in the base film have a bcc crystal structure. The base film was formed so that the elements therein had the structures 16 and 16 'segregated in the crystal grains and between the crystal grains. Next, Co-13Cr-6 was formed on the base film.
Metal magnetic film 1 made of Pt (atomic%) and having a thickness of 30 nm
4, a carbon protective film 15, 1 having a film thickness of 20 nm thereon
Formed 5 '. Finally, a lubricating film (not shown) similar to that of Example 1 was formed to manufacture a thin film type recording medium. Further, the crystal orientation of the magnetic film was examined by the same method as in Example 1,
The contents L and P of the substantially parallel crystal grains and the substantially vertical crystal grains were determined. In addition, the coercive force in the in-plane direction of the medium sample was measured by VSM. Furthermore, the recording / reproducing characteristics of the medium are set to a relative speed of 12 m.
/ S, levitating spacing 0.1 μm, CoTa
A Zr alloy is used as a recording magnetic pole material, and a recording / reproducing thin film magnetic head having an MR reproducing element is used.
The medium S / N was determined. The measurement results are shown in Tables 2 and 3.

[0025]

[Table 2]

[0026]

[Table 3]

As shown in Tables 2 and 3, by adding the elements in the second group to the underlayer, the output half recording density of 30 kFCI or more, which is the object of the present invention, and 3
A medium having the above medium S / N was obtained. L at that time
The value of / P was in the range of 1 or more and 20 or less. Here, it was confirmed by X-ray diffraction that the main crystal structure in the base film was the bcc type, and further, the fact that the elements in the second group were segregated in the crystal grains and between the crystal grains showed fluorescence. It was confirmed by X-ray analysis, Auger electron spectroscopy or photoelectron spectroscopy. Further, the same effect was observed when an underlayer film containing any of Mo, W, V, Nb, and Ta as a main component was used instead of Cr as the underlayer film.

Embodiment 3 Another embodiment of the thin film type recording medium will be described with reference to FIG. The same disk substrates 11, 12 and 12 'as in Example 1 were loaded in a magnetron sputtering apparatus, kept at a temperature of 200 ° C., and Ti, Zr, Sc, Y, Hf under the condition of an argon pressure of 2 mTorr. , Rh, Os, Zn, C
d, La, Ce, Pr, Nd, Ir, Pt, Au, P
Crystal orientation control films 17 and 1 made of elements in the second group consisting of d, Ag, Cu, Tl, Si, Ge, Sn, Pb and P.
7 ′ was formed into a film having a thickness of 100 nm (Sample Nos. 34 to 5).
8, Comparative Example: No crystal orientation control film). Example 1 on this
Cr underlayer films 13 and 13 ′ with a film thickness of 5 n
The crystal orientation control film having a thickness of 1 to 30% of the area of the Cr underlayer is not covered with the Cr underlayer. Next, a metal magnetic film 14, 14 'of Co-12Cr-4Ta (atomic%) with a film thickness of 30 nm is formed on the underlayer film, and a film thickness of 2 is formed thereon.
Carbon protective films 15 and 15 'having a thickness of 0 nm were formed. Finally, a lubricating film (not shown) similar to that in Example 1 was formed to manufacture a thin film type recording medium. Immediately after creating the medium formed by the above method, contact start and
The number of read / write error bits per disk recording surface after 50,000 stops (hereinafter abbreviated as CSS) was measured, and
The increase in the number of errors before and after S was measured. Further, the crystal orientation of the magnetic film was examined by the same method as in Example 1, and the contents L and P of substantially parallel crystal grains and substantially vertical crystal grains were obtained. In addition, the coercive force in the in-plane direction of the medium sample was measured by VSM. Further, the recording / reproducing characteristics of the medium were measured under the same magnetic head and conditions as in Example 2, and the values of D ₅₀ and medium S / N were obtained. The results of these measurements are shown in Tables 4 and 5.

[0029]

[Table 4]

[0030]

[Table 5]

As shown in Tables 4 and 5, it is an object of the present invention to form a film structure in which the crystal orientation control film of 1 to 30% of the Cr underlayer area is not covered with the Cr underlayer. A medium having an output half recording density of 30 kFCI or more and a medium S / N of 3 or more was obtained. L / at that time
The value of P was in the range of 1 or more and 20 or less. Further, by forming the crystal orientation control film, the increase in the number of errors before and after CSS was reduced, and the sliding resistance of the medium was improved. Further, as a base film, instead of Cr, Mo, W,
Similar effects were observed when an underlayer film made of an alloy containing any of V, Nb, and Ta as a main component was used.

Embodiment 4 An embodiment of the magnetic recording apparatus will be described with reference to FIG. Using four magnetic recording media 21 shown in the above embodiments, Co
A TaZr alloy is used as a recording magnetic pole material, seven MR type composite thin film magnetic heads 23 each having an MR element in a reproducing section are combined, and a magnetic recording medium driving section 22, a magnetic head driving section 24 and a recording / reproducing signal processing system 25 are provided. A magnetic recording device was prototyped. Using this magnetic recording device, we measured the recording / reproducing characteristics at a spacing of 0.08 μm, and as a result, we could increase the areal recording density more than double that of the conventional product, and a smaller magnetic recording device than the conventional device. I was able to provide it.
Further, in the present embodiment, M using CoTaZr alloy as the magnetic pole material is used.
The case of using the R-type composite thin film magnetic head has been described. However, the case of using a recording / reproducing separation type thin film magnetic head using a recording magnetic pole material such as NiFe or CoFe alloy or CoTaZ
Metal with r, FeAlSi alloy, etc. provided in the gap
It was confirmed that the same effect can be obtained even when an in-gap (MIG) recording / reproducing composite magnetic head, a conventional inductive thin film head, or a MIG head is used.

[0033]

According to the present invention, it is possible to provide a magnetic recording medium capable of high-density recording and a small-sized and large-capacity magnetic recording apparatus using the same.

[Brief description of drawings]

FIG. 1 is a sectional structural view of a thin film magnetic recording medium of Example 1 of the present invention.

FIG. 2 is a sectional structural view of a thin film magnetic recording medium of Example 2 of the present invention.

FIG. 3 is a sectional structural view of a thin film magnetic recording medium of Example 3 of the present invention.

FIG. 4 is a cross-sectional structure diagram of a magnetic recording device of Example 4 of the invention.

[Explanation of symbols]

11 ... Magnetic disk substrate, 12, 12 '... Non-magnetic plating film, 13, 13' ... Metal base film, 14, 14 '... Metal magnetic film, 15, 15' ... Non-magnetic protective film, 16, 16 '... Bottom Segregation region in the geological film, 17, 17 '... Crystal orientation control film, 21
... magnetic recording medium, 22 ... magnetic recording medium drive section, 23 ... magnetic head, 24 ... magnetic head drive section, 25 ... recording / reproducing signal processing system.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshihiro Shiroishi 1-280 Higashi-Kengokubo, Kokubunji-shi, Tokyo Inside Central Research Laboratory, Hitachi Ltd. (72) Inventor Toshiyuki Ono 1-280 Higashi-Kengokubo, Kokubunji-shi, Tokyo Hitachi, Ltd. Central Research Laboratory (72) Inventor Yasuo Yaku 1-280, Higashi Koikeku, Kokubunji, Tokyo Hitachi Central Research Institute (72) Inventor Yukio Kato 1-280, Higashi Koikeku, Kokubunji, Tokyo Hitachi Central Research Co., Ltd. In-house

Claims (9)

[Claims] 1. A magnetic recording medium having a non-magnetic substrate, a base film formed on the non-magnetic substrate, and a magnetic film formed on the base film, wherein the base film is Cr, Mo, W,
The magnetic film contains at least one element selected from the first group consisting of V, Nb, and Ta as a main component.
a first crystal grain having an easy axis of magnetization in a direction substantially parallel to the substrate surface, and a second magnetic film having an easy axis of magnetization in a direction substantially perpendicular to the substrate surface. It is substantially composed of crystal grains, and when the contents of the first and second crystal grains in the magnetic film are defined as L and P, respectively, the value of L / P is 1 or more and 20 or less. And a magnetic recording medium. 2. A part of the surface of the substrate in the base film forming portion is exposed without being covered with the base film, and a ratio of the exposed area is 1% or more and 30% or less of the base film area. The magnetic recording medium according to claim 1. 3. The crystal grain size of the underlying film is 1 nm or more and 50 n or less.
The magnetic recording medium according to claim 2, wherein the magnetic grains are less than m and the crystal grains are separated from each other. 4. The magnetic recording medium according to claim 2, wherein the crystal grains of the underlayer film have a body-centered cubic lattice type crystal structure. 5. The thickness of the base film is 0.5 nm or more and 50 n
The magnetic recording medium according to claim 2, which is less than m. 6. The undercoat film contains at least one element selected from the first group as a main component, and further comprises T
i, Zr, Sc, Y, Hf, Rh, Os, Zn, Cd,
La, Ce, Pr, Nd, Ir, Pt, Au, Pd, A
1 atom% of at least one element selected from the second group consisting of g, Cu, Tl, Si, Ge, Sn, Pb and P
In the range of 30 atomic% or less, the main crystal grains in the underlying film have a body-centered cubic lattice type crystal structure, and at least one element selected from the second group is The magnetic recording medium according to claim 1, wherein the magnetic recording medium is segregated at grain boundaries. 7. The magnetic recording medium further comprises Ti, Zr, Sc, Y, Hf, formed between the substrate and the base film.
Rh, Os, Zn, Cd, La, Ce, Pr, Nd, I
r, Pt, Au, Pd, Ag, Cu, Tl, Si, G
It has a crystal orientation control film containing at least one element selected from the second group consisting of e, Sn, Pb and P as a main component, and a part of the surface of the crystal orientation control film is the underlayer film. The magnetic recording medium according to claim 1, wherein the magnetic recording medium is exposed without being covered, and the ratio of the exposed area is 1% or more and 30% or less of the area of the base film. 8. The thickness of the base film is 0.5 nm or more and 50 n
The magnetic recording medium according to claim 7, which is less than m. 9. A magnetic disk device comprising a magnetic recording medium, a magnetic recording medium rotation drive section, a magnetic head, a magnetic head drive section, and a recording / reproducing signal processing system, wherein the magnetic recording medium is any one of claims 1 to 3. 9. A magnetic recording device comprising the magnetic recording medium according to claim 8.