JP3132658B2 - Perpendicular magnetic recording medium and magnetic recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a perpendicular magnetic recording medium used as a magnetic disk or the like and a magnetic recording apparatus using the perpendicular magnetic recording medium.

[0002]

2. Description of the Related Art In recent years, with the increase in capacity and miniaturization of hard disk drives accompanying the progress of personal computers and workstations, magnetic disks as recording media are required to have higher areal densities. But,
With the longitudinal recording method using magnetic disks, which is now widely used, in order to achieve high recording density, there is a problem of thermal fluctuation of recording magnetization due to miniaturization of recording bits and a high coercive force that may exceed the recording capacity of the recording head Problems arise. Therefore, a perpendicular magnetic recording method is being studied as a means for solving these problems and greatly improving the areal recording density. As one of the perpendicular magnetic recording media for realizing this, there is a perpendicular two-layer medium composed of a soft magnetic film having a high magnetic permeability and a perpendicular magnetic film having a high perpendicular anisotropy.

FIG. 51 is a schematic sectional view showing a conventional example of such a perpendicular magnetic recording medium.

The perpendicular magnetic recording medium 50 has a soft magnetic backing layer 52 and a perpendicular magnetization film 54 formed on a substrate 56 in this order. For example, as a soft magnetic film, NiF
A CoCr-based alloy is used as the e film and the perpendicular magnetization film (Journal of the Japan Society of Applied Magnetics, Vol. 8, No. 1, 1984, p1).
7).

Here, an example of a perpendicular magnetic head will be described with reference to FIG. The perpendicular magnetic recording medium 61 having a two-layer film structure
On a nonmagnetic disk substrate 62 made of aluminum, glass, or the like, the surface of which has been subjected to NiP plating or alumite treatment, a soft magnetic layer having a high magnetic permeability made of, for example, a 1 μm thick NiFe film (soft magnetic underlayer) ) 63 and a perpendicular recording layer 6 made of a 0.15 μm thick CoCr film having an easy axis of magnetization perpendicular to the thickness direction of the soft magnetic layer 63.
4 are sequentially laminated.

[0006] A recording magnetic field from a perpendicular magnetic head 65 for recording / reproducing information to / from the perpendicular magnetic recording medium 61 having such a configuration is obtained by vertically magnetizing the perpendicular recording layer 64 and then immediately magnetizing the perpendicular recording layer 64. Recording is performed by a magnetic circuit that passes through the soft magnetic layer 63 in the horizontal direction, passes through the vertical recording layer 64 vertically again, and returns to the perpendicular magnetic head 65. Further, the main magnetic pole 66 of the perpendicular magnetic head 65 is magnetized by the recording magnetic field leaking from the already recorded perpendicular recording layer 64, and the coil 6 interlinking with the main pole 66 of the perpendicular magnetic head 65.
By outputting the voltage generated at 7 as a reproduction signal, reproduction can be performed.

[0007]

However, FIG.
In such a conventional medium, there is a problem of instability of recording magnetization with respect to an external magnetic field. This is because the underlying soft magnetic film 52
Of the underlying soft magnetic film 5
2 has a high magnetic permeability, and has an underlying soft magnetic film 5 against an external magnetic field.
This is because the magnetization of the second magnetic field reacts sensitively, and this promotes the concentration of the magnetic flux of the external magnetic field on the main magnetic pole 66 of the perpendicular magnetic head 65 shown in FIG . For this reason, demagnetization or demagnetization of the magnetization recorded in the perpendicular recording layer occurs.

Such an external floating magnetic field is generated from a motor for rotating a disk in a magnetic disk disposed close to the magnetic disk, a motor used for positioning a head, and the like. Although these magnetic fields are extremely weak, if they are concentrated at the tip of the main pole of the perpendicular magnetic head, they may induce domain wall movement of the underlying soft magnetic film, demagnetizing or demagnetizing the recording magnetization. It is a fatal defect.

An object of the present invention is to provide a novel perpendicular magnetic recording medium which overcomes the instability of recording magnetization with respect to an external magnetic field and is excellent in the stability of recording magnetization with respect to an external magnetic field. .

[0010]

A perpendicular magnetic recording medium according to the present invention is a perpendicular magnetic recording medium comprising a combination of an underlayer soft magnetic film and a perpendicular magnetization film, wherein the underlayer soft magnetic film has a magnetic permeability of 50 to 1,000. The whole of the underlying soft magnetic film
Has a coercive force of 2 (Oe) or more and 30 (Oe) or less .

Further, the perpendicular magnetic recording medium according to the present invention comprises:
In perpendicular magnetic recording medium that combines the soft magnetic underlayer film and a perpendicular magnetization film, the permeability of the lower soft magnetic film 50 more than 5
00 Ri der hereinafter overall coercivity of the lower soft magnetic film is 2
(Oe) or more and 30 (Oe) or less .

Further, the perpendicular magnetic recording medium according to the present invention comprises:
In perpendicular magnetic recording medium that combines the soft magnetic underlayer film and a perpendicular magnetization film, the permeability of the lower soft magnetic film 50 more than 1
00 Ri der hereinafter overall coercivity of the lower soft magnetic film is 2
(Oe) or more and 30 (Oe) or less .

[0013]

Further, the perpendicular magnetic recording medium according to the present invention comprises:
In the above perpendicular magnetic recording medium, the coercive force of the magnetic film of the underlying soft magnetic film from the substrate side in the magnetic film up to 10 nm is 30 Oe or more.

Further, the perpendicular magnetic recording medium according to the present invention comprises:
In the above perpendicular magnetic recording medium, the thickness of the underlying soft magnetic film is 300 nm or less.

Further, the perpendicular magnetic recording medium according to the present invention comprises:
In the above perpendicular magnetic recording medium, the material of the underlying soft magnetic film is an FeSiAl alloy.

Also, the perpendicular magnetic recording medium according to the present invention
In the perpendicular magnetic recording medium, wherein the material of the lower soft magnetic film is a _{Fe 84.9 Si x Al 15.1-x} (8.0 ≦ X ≦ 12.0).

Also, the perpendicular magnetic recording medium according to the present invention
In the above perpendicular magnetic recording medium, the material of the underlying soft magnetic film is Fe _84.9 Si _9.6 Al _5.5 (wt%).

Also, the perpendicular magnetic recording medium according to the present invention
In the above-described perpendicular magnetic recording medium, an alloy in which the element M is added to the material of the underlying soft magnetic film, where M is Ta, Ti, Z
It is characterized by containing arbitrary two elements of r, Mo, and Nb.

Also, the perpendicular magnetic recording medium according to the present invention
In the above perpendicular magnetic recording medium, the material of the underlying soft magnetic film is FeTaN.

[0021]

Further, the perpendicular magnetic recording medium according to the present invention
In the above perpendicular magnetic recording medium, the material of the perpendicular magnetization film is C
oCrR alloy, where R is Pt, Ta, La, L
It is characterized by containing any three elements of u, Pr and Sr.

The magnetic recording apparatus according to the present invention is a magnetic recording apparatus for recording information on a perpendicular magnetic recording medium, wherein the perpendicular magnetic recording medium has a base soft magnetic film and a perpendicular magnetic film laminated on a substrate in order. The magnetic permeability of the underlying soft magnetic film is 50
Above 100 Ri der hereinafter the entirety of the lower soft magnetic film coercive
The force is 2 (Oe) or more and 30 (Oe) or less .

Further, in the magnetic recording apparatus according to the present invention, an alloy in which an element M is added to the material of the underlying soft magnetic film is used, and any two of Ta, Ti, Zr, Mo, and Nb are used as the element M. It is characterized by including.

Further, in the magnetic recording apparatus according to the present invention, the material of the perpendicular magnetization film is a CoCrR alloy, and the R includes any three elements of Pt, Ta, La, Lu, Pr, and Sr. Features.

[Operation] In the perpendicular magnetic recording medium of the present invention,
Rather than making the underlying soft magnetic film a film with good soft magnetic properties, the permeability of the underlying soft magnetic film is made less responsive to an external magnetic field by lowering the magnetic permeability than before,
The concentration of the magnetic flux of the external magnetic field on the main pole of the perpendicular magnetic head is suppressed.

For this reason, it is possible to obtain a perpendicular medium which is hardly demagnetized or demagnetized in the magnetization recorded in the perpendicular recording layer and has excellent stability of the recorded magnetization against an external magnetic field.

Further, in the magnetic recording apparatus of the present invention, by using the above-described perpendicular magnetic recording medium, the magnetic permeability of the underlying soft magnetic film is optimized so as to optimize the reactivity of the magnetization of the underlying soft magnetic film to the external magnetic field, and the influence of the stray magnetic field is reduced. A device that is not easily received can be provided.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to the present invention will be described.
This will be described in detail with reference to the drawings.

[Description of Structure] FIG. 1 is a schematic sectional view showing an embodiment of a perpendicular magnetic recording medium according to the present invention.

The perpendicular magnetic recording medium 20 according to the present embodiment
Are a soft magnetic underlayer 24 having a low magnetic permeability and a perpendicular magnetic film 2
8 are formed on the substrate 22.

[Explanation of Operation] As the underlying soft magnetic film 24,
The following materials: FeSiAl film, FeSiAlM
Film, FeTaN film, or FeTaNM film (M is T
a, Ti, Zr, Mo, and Nb) to suppress the magnetic permeability of the underlying soft magnetic film 24, thereby improving the soft magnetic characteristics of the underlying soft magnetic film 24. Problems that occur when the material has a large magnetic permeability,
That is, the instability of the recording magnetization with respect to the external magnetic field can be solved.

[0033]

[Embodiment 1] [Description of Configuration of Embodiment 1] FIG. 2 shows an embodiment of the present invention.
This will be described in detail with reference to FIG. A 6-inch Fe _84.9 layer was formed on a substrate 12 having a magnetic disk diameter of 2.5 inches by sputtering.
Using a Si _9.6 Al _5.5 (wt%) target, Fe
_84.9 Si _9.6 Al _5.5 film 16 is _deposited at a substrate temperature of 500 ° C. for 500 times.
nm. The film formation conditions are as follows: Initial vacuum 5 × 10 ⁻⁷ mTor
At r, input power 0.5kw, argon gas pressure 4mT
orr, and the film formation rate was 3 nm / sec. Co ₇₈ Cr on it
Co ₇₈ Cr ₁₉ PtLaLu film 1 using ₁₉ PtLaLu (at%) target
8 was deposited to a thickness of 100 nm. Furthermore, a C protective film is further
nm. This medium is referred to as a conventional medium A1. On the other hand, only the substrate temperature at the time of _forming the Fe _84.9 Si _9.6 Al _5.5 film was changed, and the substrate temperature was changed to 400 ° C., 350 ° C., 300 ° C., 25 ° C.
Media prepared by forming a film at 0 ° C., 200 ° C., 100 ° C., and room temperature are respectively referred to as media A2, A3, A4, and A
5, A6, A7, and A8. A medium in which the thickness of the underlying soft magnetic film of the medium A2 of the present invention is 250 nm and 350 nm is referred to as a medium A9 of the present invention and a conventional medium AA1.

[Explanation of Operation of Embodiment 1] The magnetic permeability of the Fe _84.9 Si _9.6 Al _5.5 film formed at each substrate temperature, the coercive force of the whole film, and the Fe _84.9 Si _9.6 Al _5.5 film of only 10 nm were formed. The coercive force of the film was measured. Each measurement value is shown in FIG.

In FIG. 3, an experiment of recording / reproducing with respect to the conventional medium A1 and the mediums A2 to A10 of the present invention was conducted by using a single pole head
This was performed using a D / MR composite head. Where ID / M
The recording track width of the R composite head is 4 μm, the reproduction track width is 3 μm, the recording gap length is 0.4 μm, and the reproduction gap length is 0.32 μm. The track width of the single pole head is 10 μm, and the main pole film thickness is 0.4 μm. The evaluation was performed under the conditions of a recording current of 10 mAop, a sense current of 12 mA, a peripheral speed of 12.7 m / s, a flying height of 45 nm, and a noise band band of 45 MHz.

First, in order to examine the stability of recording magnetization with respect to an external magnetic field, a signal was recorded on the conventional media A1, AA1 and the media A2 to A9 of the present invention with a single pole head, and then a DC magnetic field was applied to the media by a Helmholtz coil. 1-30 Oe
The reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. The result is shown in FIG.
Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage. Since the FeSiAl film originally does not have a domain wall structure, when it is used as an underlayer soft magnetic film having a domain wall structure such as a NiFe film, the use of an underlayer soft magnetic film having a domain wall structure in the perpendicular double-layered medium is more difficult. There is an advantage that the magnetic flux is not easily concentrated on the magnetic pole, and the output signal is easily stabilized with respect to the external magnetic field.

As can be seen from FIG. 4, the conventional media A1, A
A1 shows that the soft magnetic properties of the underlying soft magnetic film are good, the magnetic permeability is sufficiently large, and the coercive force is sufficiently small, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more.

Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can be increased to increase the coercive force of the entire film. Invention media A2 to A9
In the case of, because the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the entire film is large, it is possible to make it difficult for external magnetic flux to be concentrated on the main pole of the single-pole head, and to provide a strong perpendicular to the external magnetic field. A two-layer medium could be obtained. Further, in the case of the conventional medium AA1, the ratio of the initial coercive force to the coercive force of the entire film becomes smaller because the thickness of the underlying soft magnetic film is larger than that of the medium A2 of the present invention, and the coercive force of the entire film is reduced. A2
It is thought that it became weaker to an external magnetic field.

From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the whole film is 2 Oe to 30 Oe, the initial coercive force is 30 Oe or more, and the thickness of the underlying soft magnetic film is 300
By setting the thickness to be equal to or less than nm, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 5 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 5, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media A1 and AA1 and the media A2, A3 and A9 of the present invention have large magnetic permeability of the underlying soft magnetic film, and can obtain a sufficient reproduction output. The mediums A4, A5 of the present invention have smaller magnetic permeability of the underlying soft magnetic film than the mediums A2, A3, A9 of the present invention, so that the reproduction output is small. However, the reproduction output of the mediums A2, A3, A9 of the present invention is small. It is about 80%, which is still sufficient as the absolute value of the reproduction output. In the media A6 and A7 of the present invention, since the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media A4 and A5 of the present invention, the reproduction output is further reduced.
It is about 60% of the reproduction output of A3 and A9, and it can be said that the reproduction output is still sufficient as an absolute value. However, in the case of the medium A8 of the present invention, the magnetic permeability of the underlying soft magnetic film is too small.
Playback output is not enough.

From the above, from the viewpoint of the durability of the output signal with respect to the external magnetic field, it is necessary to use the media A2 to A9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is 50 or more and 10 or more.
It is preferably 0 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

Further, the durability of the output signal to the external magnetic field is caused by the interaction between the main pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetization film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

Example 2 In Example 1, Co ₇₈ Cr ₁₉ Pt was used.
Co ₇₈ Cr ₁₉ TaLaSr instead of LaLu (at%) target
(At%) A medium was produced in the same manner as in Example 1 using a target. The media prepared in the same manner as in Example 1 were prepared in the same manner as in Example 1, except that the conventional media B1, BB1, and the media B2, B3, B4, B5, B6, B7, B8, B9 of the present invention were used.
And Fe _84.9 Si _9.6 A deposited at each substrate temperature
The magnetic permeability of the _l5.5 film was measured. Fig. 6 shows the value of each magnetic permeability.
Shown in

Conventional media B1, BB1 and media B2 of the present invention
Experiments on recording and reproduction of B9 to B9 were performed under the same recording and reproduction conditions as in Example 1.

First, in order to examine the stability of the recording magnetization with respect to an external magnetic field, a signal was recorded on the conventional media B1, BB1 and the media B2 to B9 of the present invention by a single pole head, and then a DC magnetic field was applied to the media by a Helmholtz coil. The voltage was applied in the range of 1 to 30 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. The result is shown in FIG. Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 7, the conventional media B1, B
B1 has good soft magnetic properties of the underlying soft magnetic film, has sufficiently large magnetic permeability, and has a sufficiently small coercive force, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the media B2 to B9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the whole film is large, it is difficult for the magnetic flux from the outside to concentrate on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. Further, in the case of the conventional medium BB1, the ratio of the initial coercive force to the coercive force of the entire film is smaller because the thickness of the underlying soft magnetic film is larger than that of the medium B2 of the present invention, and the coercive force of the entire film is reduced. It is considered that it became smaller than B2 and became weak against an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
As described above, by setting the thickness of the underlying soft magnetic film to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 8 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 8, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media B1 and BB1 and the media B2, B3 and B9 of the present invention have large magnetic permeability of the underlying soft magnetic film, and can obtain a sufficient reproduction output. The mediums B4, B5 of the present invention have a smaller reproduction output because the magnetic permeability of the underlying soft magnetic film is smaller than the mediums B2, B3, B9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. Since the mediums B6 and B7 of the present invention have smaller magnetic permeability of the underlying soft magnetic film than the mediums B4 and B5 of the present invention, the reproduction output is further reduced.
This is about 60% of the reproduction output of B3 and B9, and it can be said that the absolute value of the reproduction output is still sufficient. However, in the case of the medium B8 of the present invention, since the magnetic permeability of the underlying soft magnetic film is too small,
Playback output is not enough.

From the above, from the viewpoint of the durability of the output signal with respect to the external magnetic field, it is necessary to use the media B2 to B9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetic film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

Example 3 In Example 1, Co ₇₈ Cr ₁₉ Pt was used.
Co ₇₈ Cr ₁₉ PtLuPr instead of LaLu (at%) target
(At%) A medium was produced in the same manner as in Example 1 using a target. The media produced in the same manner as in Example 1 were prepared in the same manner as in Example 1, except that the conventional media C1, CC1, and the media C2, C3, C4, C5, C6, C7, C8, C9 of the present invention were obtained.
And Fe _84.9 Si _9.6 A deposited at each substrate temperature
The magnetic permeability of the _l5.5 film was measured. FIG. 9 shows the values of the respective magnetic permeability.
Shown in

Conventional media C1, CC1 and media C2 of the present invention
Experiments of recording and reproduction of C9 to C9 were performed under the same recording and reproduction conditions as in Example 1.

First, in order to examine the stability of recording magnetization with respect to an external magnetic field, a signal was recorded on the conventional media C1 and CC1 and the media C2 to C9 of the present invention with a single pole head, and then a direct current magnetic field was applied to the media by a Helmholtz coil. The voltage was applied in the range of 1 to 30 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. The result is shown in FIG.
Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 10, the conventional media C1,
CC1 has good soft magnetic properties of the underlying soft magnetic film, has a sufficiently large magnetic permeability, and has a sufficiently small coercive force, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the media C2 to C9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the entire film is large, it is difficult for the magnetic flux from the outside to concentrate on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. Further, in the case of the conventional medium CC1, the ratio of the initial coercive force to the coercive force of the entire film is smaller because the thickness of the underlying soft magnetic film is larger than that of the medium C2 of the present invention. It is considered that it became smaller than C2 and became weak against an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
As described above, by setting the thickness of the underlying soft magnetic film to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 11 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 11, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media C1 and CC1 and the media C2, C3 and C9 of the present invention have large magnetic permeability of the underlying soft magnetic film, and can obtain a sufficient reproduction output. In the media B4 and B5 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media C2, C3 and C9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output.

In the media C6 and C7 of the present invention, since the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media C4 and C5 of the present invention, the reproduction output is further reduced.
This is about 60% of the reproduction output of C3 and C9, and it can be said that the absolute value of the reproduction output is still sufficient. However, in the case of the medium C8 of the present invention, since the magnetic permeability of the underlying soft magnetic film is too small,
Playback output is not enough.

From the above, from the viewpoint of the durability of the output signal with respect to the external magnetic field, it is necessary to use the media C2 to C9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal to an external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetization film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

[Example 4] In Example 1, Fe _84.9 S
i _9.6 Al _5.5 Fe instead of (wt%) Target _84.9
The Si _8.0 Al _7.1 (wt%) target was changed to Co ₇₈ Cr ₁₉
Co ₇₈ C instead of PtLaLu (at%) target
A medium was produced in the same manner as in Example 1 using an r ₁₉ TaPrLu (at%) target. However, Fe _84.9 Si
The substrate temperature at the time of forming the _8.0 Al _7.1 film was 450 ° C, 400 ° C,
Media prepared by forming a film at 350 ° C., 300 ° C., 250 ° C., 200 ° C., and room temperature are referred to as mediums D2 and D of the present invention, respectively.
3, D4, D5, D6, D7, D8. Further, the thickness of the underlying soft magnetic film of the medium D2 of the present invention is set to 250 nm, 350 nm.
The medium of nm is referred to as a medium D9 of the present invention and a conventional medium DD1.

Fe _84.9 Si deposited at each substrate temperature
The magnetic permeability of the _8.0 Al _7.1 film was measured. FIG. 12 shows the values of the respective magnetic permeability.

Conventional media D1, DD1 and media D2 of the present invention
Experiments on recording and reproduction of D9 to D9 were performed under the same recording and reproduction conditions as in Example 1.

First, in order to examine the stability of the recording magnetization with respect to an external magnetic field, a signal was recorded on the conventional media D1 and DD1 and the media D2 to D9 of the present invention by a single pole head, and then a DC magnetic field was applied to the media by a Helmholtz coil. The voltage was applied in the range of 1 to 30 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. FIG. 13 shows the result.
Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 13, the conventional media D1,
DD1 has good soft magnetic properties of the underlying soft magnetic film, has a sufficiently high magnetic permeability, and has a sufficiently small coercive force, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the media D2 to D9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the entire film is large, it is difficult for external magnetic flux to concentrate on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. In addition, in the case of the conventional medium DD1, the ratio of the initial coercive force to the coercive force of the entire film is smaller because the thickness of the underlying soft magnetic film is larger than that of the medium D2 of the present invention, and the coercive force of the entire film is reduced. It is considered that it became smaller than D2 and became weak against an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
As described above, by setting the thickness of the underlying soft magnetic film to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 14 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 14, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media D1 and DD1 and the media D2, D3 and D9 of the present invention have a large magnetic permeability of the underlying soft magnetic film, and can obtain a sufficient reproduction output. In the media D4 and D5 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media D2, D3 and D9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. In the media D6 and D7 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media D4 and D5 of the present invention.
2, 60% of the reproduction output of D3 and D9, and it can be said that the absolute value of the reproduction output is still sufficient. However, in the case of the medium D8 of the present invention, since the magnetic permeability of the underlying soft magnetic film is too small, a sufficient reproduction output cannot be obtained.

From the above, from the viewpoint of the durability of the output signal with respect to the external magnetic field, it is necessary to use the media D2 to D9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and thus does not depend much on the thickness of the perpendicular magnetization film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

[Embodiment 5]_84.9S
i_9.6Al_5.5(Wt%) Fe instead of target_84.9
Si_12.0Al_3.1(Wt%)₇₈Cr
₁₉Co instead of PtLaLu (at%) target₇₈
Cr₁₉Implemented using TaPrSr (at%) target
A medium was produced in the same manner as in Example 1. Where Fe_84.9S
i_12.0Al _3.1The substrate temperature during film formation is 450 ° C., 400
℃, 350 ℃, 300 ℃, 250 ℃, 200 ℃, and room
The medium prepared by forming a film at a high temperature is a medium E2 of the present invention,
E3, E4, E5, E6, E7, E8. Also book
The thickness of the underlying soft magnetic film of the invention medium E2 is set to 250 nm and 35
The medium having a thickness of 0 nm is referred to as a medium E9 of the present invention or a conventional medium EE1.
I do.

Fe _84.9 Si deposited at each substrate temperature
The magnetic permeability of the _12.0 Al _3.1 film was measured. FIG. 15 shows the values of the respective magnetic permeability.

Conventional media E1, EE1 and media E2 of the present invention
The recording and reproduction experiments of E9 to E9 were performed under the same recording and reproduction conditions as in Example 1. First, in order to examine the stability of the recording magnetization with respect to an external magnetic field, a signal was recorded on the conventional media E1 and EE1 and the media E2 to E9 of the present invention with a single pole head, and then a DC magnetic field was applied to the media with a Helmholtz coil.
The voltage was applied in the range of 0 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. The result is shown in FIG. Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 16, the conventional media E1,
EE1 shows that the soft magnetic characteristics of the underlying soft magnetic film are good, the magnetic permeability is sufficiently large, and the coercive force is sufficiently small, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the media E2 to E9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the whole film is large, it is difficult for the magnetic flux from the outside to concentrate on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. Further, in the case of the conventional medium EE1, the ratio of the initial coercive force to the coercive force of the entire film is smaller because the thickness of the underlying soft magnetic film is larger than that of the medium E2 of the present invention. It is considered that it became smaller than EE2 and became weak to an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
By setting the thickness of the soft magnetic underlayer to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 17 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 17, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media E1 and EE1 and the media E2, E3 and E9 of the present invention have a large magnetic permeability of the underlying soft magnetic film, and a sufficient reproduction output can be obtained. In the media E4 and E5 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media E2, E3 and E9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. In the media E6 and E7 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media E4 and E5 of the present invention.
It is about 60% of the reproduction output of 2, E3, and E9, and it can be said that it is still sufficient as the absolute value of the reproduction output. However, in the case of the medium E8 of the present invention, since the magnetic permeability of the underlying soft magnetic film is too small, a sufficient reproduction output cannot be obtained.

From the above, from the viewpoint of the durability of the output signal with respect to the external magnetic field, it is necessary to use the media E2 to E9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetic film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

[Embodiment 6] In the embodiment 1, Fe _84.9 S
i _9.6 Al _5.5 Fe instead of (wt%) Target _82.9
A medium was produced in the same manner as in Example 1 using a Si _9.6 Al _5.5 TaZr (wt%) target. Addition of TaZr has an effect of making crystal grains fine. The media manufactured in the same manner as in Example 1 were manufactured in the same manner as in Example 1 except that the conventional media F1 and FF1, and the media F2, F3, F4, F5, and F of the present invention, respectively.
6, F7, F8, and F9. The magnetic permeability of the Fe _82.9 Si _9.6 Al _5.5 TaZr film formed at each substrate temperature was measured. FIG. 18 shows the values of the respective magnetic permeability.

Conventional media F1, FF1 and media F2 of the present invention
The experiments of recording and reproduction of F9 to F9 were performed under the same recording and reproduction conditions as in Example 1.

First, in order to examine the stability of the recording magnetization with respect to an external magnetic field, a signal was recorded on the conventional media F1 and FF1 and the media F2 to F9 of the present invention with a single pole head, and then a DC magnetic field was applied to the media by a Helmholtz coil. The voltage was applied in the range of 1 to 30 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. The result is shown in FIG.
Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 19, the conventional medium F1,
FF1 has good soft magnetic properties of the underlying soft magnetic film, has sufficiently high magnetic permeability, and has a sufficiently small coercive force, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the media F2 to F9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the entire film is large, the magnetic flux from the outside is hardly concentrated on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. Further, in the case of the conventional medium FF1, the ratio of the initial coercive force to the coercive force of the entire film becomes smaller because the thickness of the underlying soft magnetic film is larger than that of the medium F2 of the present invention. It is considered that it became smaller than F2 and became weak to an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
As described above, by setting the thickness of the underlying soft magnetic film to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 20 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 20, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media F1 and FF1 and the media F2, F3 and F9 of the present invention have a large magnetic permeability of the underlying soft magnetic film, and a sufficient reproduction output can be obtained. In the media F4 and F5 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media F2, F3 and F9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. In the media F6 and F7 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media F4 and F5 of the present invention.
2, 60% of the reproduction output of F3 and F9, and it can be said that the absolute value of the reproduction output is still sufficient. However, in the case of the medium F8 of the present invention, the reproduction output cannot be sufficiently obtained because the magnetic permeability of the underlying soft magnetic film is too small.

From the above, from the viewpoint of the durability of the output signal with respect to the external magnetic field, it is necessary to use the media F2 to F9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and thus does not depend much on the thickness of the perpendicular magnetic film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

[Embodiment 7] In Example 2, Fe _84.9 S
i _9.6 Al _5.5 Fe instead of (wt%) Target _82.9
A medium was manufactured in the same manner as in Example 1 using a Si _9.6 Al _5.5 TiMo (wt%) target. Addition of TiMo has an effect of making crystal grains fine. The media manufactured in the same manner as in Example 1 were manufactured in the same manner as in Example 1, except that the conventional media G1 and GG1, and the media G2, G3, G4, G5, and G of the present invention, respectively.
6, G7, G8, and G9.

Fe _82.9 Si deposited at each substrate temperature
The magnetic permeability of the _9.6 Al _5.5 TiMo film was measured. FIG. 21 shows the values of the respective magnetic permeability.

Conventional media G1, GG1 and media G2 of the present invention
The experiments of recording and reproduction of G9 to G9 were performed under the same recording and reproduction conditions as in Example 1.

First, in order to examine the stability of the recording magnetization with respect to an external magnetic field, signals were recorded on the conventional media G1, GG1 and the media G2 to G9 of the present invention with a single-pole head, and then a DC magnetic field was applied to the media by a Helmholtz coil. The voltage was applied in the range of 1 to 30 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. The result is shown in FIG.
Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 22, the conventional media G1,
GG1 has good soft magnetic properties of the underlying soft magnetic film, has sufficiently high magnetic permeability, and has a sufficiently small coercive force, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the mediums G2 to G9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the whole film is large, it is difficult for external magnetic flux to concentrate on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. In addition, in the case of the conventional medium GG1, the ratio of the initial coercive force to the coercive force of the entire film is smaller because the thickness of the underlying soft magnetic film is thicker than that of the medium G2 of the present invention, and the coercive force of the entire film is reduced. It is considered that the value became smaller than G2 and became weaker against an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
As described above, by setting the thickness of the underlying soft magnetic film to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 23 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 23, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media G1 and GG1 and the media G2, G3 and G9 of the present invention have a large magnetic permeability of the underlying soft magnetic film, and a sufficient reproduction output can be obtained. The mediums G4 and G5 of the present invention have a smaller reproducing output because the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than the mediums G2, G3 and G9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. In the media G6 and G7 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media G4 and G5 of the present invention.
2, 60% of the reproduction output of G3 and G9, and it can be said that the absolute value of the reproduction output is still sufficient. However, in the case of the medium G8 of the present invention, since the magnetic permeability of the underlying soft magnetic film is too small, a sufficient reproduction output cannot be obtained.

From the above, from the viewpoint of the durability of the output signal with respect to the external magnetic field, it is necessary to use the media G2 to G9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetic film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

[Embodiment 8] In the third embodiment, Fe _84.9 S
i _9.6 Al _5.5 Fe instead of (wt%) Target _82.9
A medium was manufactured in the same manner as in Example 1 using a Si _9.6 Al _5.5 ZrNb (wt%) target. Addition of ZrNb has an effect of making crystal grains fine. The media manufactured in the same manner as in Example 1 were manufactured in the same manner as in Example 1 except that the conventional media H1, HH1, and the media H2, H3, H4, H5, and H of the present invention were used.
6, H7, H8, and H9. The magnetic permeability of the Fe _82.9 Si _9.6 Al _5.5 ZrNb film formed at each substrate temperature was measured. FIG. 24 shows the values of the respective magnetic permeability.

Conventional media H1, HH1 and media H2 of the present invention
The experiments of recording and reproduction of H9 to H9 were performed under the same recording and reproduction conditions as in Example 1.

First, in order to examine the stability of recording magnetization with respect to an external magnetic field, signals were recorded on the conventional media H1 and HH1 and the media H2 to H9 of the present invention with a single-pole head, and then a DC magnetic field was applied to the media by a Helmholtz coil. The voltage was applied in the range of 1 to 30 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. FIG. 25 shows the result.
Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 25, the conventional medium H1,
HH1 has an excellent soft magnetic property of the underlying soft magnetic film, has sufficiently high magnetic permeability, and has a sufficiently small coercive force, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the media H2 to H9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the whole film is large, it is difficult for the magnetic flux from the outside to be concentrated on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. Also, in the case of the conventional medium HH1, the ratio of the initial coercive force to the coercive force of the entire film becomes smaller because the thickness of the underlying soft magnetic film is larger than that of the medium H2 of the present invention, and the coercive force of the entire film is reduced. It is considered that it became smaller than H2 and became weak against an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
As described above, by setting the thickness of the underlying soft magnetic film to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 26 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 26, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media H1, HH1 and the media H2, H3, H9 of the present invention have a large magnetic permeability of the underlying soft magnetic film, and can obtain a sufficient reproduction output. In the media H4 and H5 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media H2, H3 and H9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. In the media H6 and H7 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media H4 and H5 of the present invention.
2, 60% of the reproduction output of H3 and H9, which is still sufficient as the absolute value of the reproduction output. However, in the case of the medium H8 of the present invention, since the magnetic permeability of the underlying soft magnetic film is too small, a sufficient reproduction output cannot be obtained.

From the above, from the viewpoint of the durability of the output signal with respect to the external magnetic field, it is necessary to use the mediums H2 to H9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetization film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

[Embodiment 9] In Embodiment 4, Fe _84.9 S
Fe _82.9 instead of i _8.0 Al _7.1 (wt%) target
A medium was produced in the same manner as in Example 4 using a Si _8.0 Al _7.1 TaZr (wt%) target. Addition of TaZr has an effect of making crystal grains fine. The mediums of the present invention are J2, J3, J4, J5, J6, J7, and J8, respectively.
Further, the thickness of the underlying soft magnetic film of the medium J2 of the present invention is set to 250 n.
The medium having m and 350 nm is referred to as a medium J9 of the present invention and a conventional medium JJ1.

Fe _82.9 Si deposited at each substrate temperature
The magnetic permeability of the _8.0 Al _7.1 TaZr film was measured. FIG. 27 shows the values of the respective magnetic permeability.

Conventional media J1, JJ1 and media J2 of the present invention
Experiments on recording and reproduction of J9 to J9 were performed under the same recording and reproduction conditions as in Example 1.

First, in order to examine the stability of recording magnetization with respect to an external magnetic field, signals were recorded on the conventional media J1 and JJ1 and the media J2 to J9 of the present invention using a single-pole head, and then a DC magnetic field was applied to the media by a Helmholtz coil. The voltage was applied in the range of 1 to 30 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. The result is shown in FIG.
Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 28, the conventional media J1,
JJ1 indicates that the soft magnetic property of the underlying soft magnetic film is good, the magnetic permeability is sufficiently large, and the coercive force is sufficiently small, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the media J2 to J9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the whole film is large, it is difficult for the magnetic flux from the outside to concentrate on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. Further, in the case of the conventional medium JJ1, the ratio of the initial coercive force to the coercive force of the entire film is smaller because the film thickness of the underlying soft magnetic film is thicker than that of the medium J2 of the present invention, and the coercive force of the entire film is reduced. J2 is considered to be smaller than J2 and weaker to an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
As described above, by setting the thickness of the underlying soft magnetic film to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 29 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 29, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media J1 and JJ1 and the media J2, J3 and J9 of the present invention have a large magnetic permeability of the underlying soft magnetic film, and a sufficient reproduction output can be obtained. In the media J4 and J5 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media J2, J3 and J9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. In the media J6 and J7 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media J4 and J5 of the present invention.
2, 60% of the reproduction output of J3 and J9, which is still sufficient as the absolute value of the reproduction output. However, in the case of the medium J8 of the present invention, the reproduction output cannot be sufficiently obtained because the magnetic permeability of the underlying soft magnetic film is too small.

From the above, from the viewpoint of the durability of the output signal to the external magnetic field, it is necessary to use the media J2 to J9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetic film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

[Embodiment 10] In Example 5, Fe _{84.9 was used.}
Fe instead of Si _12.0 Al _3.1 (wt%) target
_A medium was manufactured in the same manner as in Example 5 using an _82.9 Si _12.0 Al _3.1 TiMo (wt%) target. TiMo
Has an effect of making crystal grains fine. These are the media K2, K3, K4, K5, K6, K7, and K8 of the present invention, respectively. Further, the thickness of the underlying soft magnetic film of the medium E2 of the present invention is set to 2
The media having a thickness of 50 nm and 350 nm are referred to as a medium K9 of the present invention and a conventional medium KK1.

Fe _82.9 Si deposited at each substrate temperature
The magnetic permeability of the _12.0 Al _3.1 TiMo film was measured. FIG. 30 shows the values of the respective magnetic permeability.

Conventional media K1 and KK1 and media K2 of the present invention
Experiments on recording and reproduction of K9 to K9 were performed under the same recording and reproduction conditions as in Example 1.

First, in order to examine the stability of the recording magnetization with respect to an external magnetic field, a signal was recorded on the conventional media K1 and KK1 and the media K2 to K9 of the present invention with a single-pole head, and then a DC magnetic field was applied to the media by a Helmholtz coil. The voltage was applied in the range of 1 to 30 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. The result is shown in FIG.
Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 31, the conventional medium K1,
KK1 has good soft magnetic properties of the underlying soft magnetic film, has a sufficiently large magnetic permeability, and has a sufficiently small coercive force, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the mediums K2 to K9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the entire film is large, it is difficult for the magnetic flux from the outside to concentrate on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. Further, in the case of the conventional medium KK1, the ratio of the initial coercive force to the coercive force of the entire film becomes smaller because the thickness of the underlying soft magnetic film is larger than that of the medium K2 of the present invention, and the coercive force of the entire film is reduced. It is considered that it became smaller than KK2 and became weak to an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
By setting the thickness of the soft magnetic underlayer to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 32 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 32, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media K1 and KK1 and the media K2, K3 and K9 of the present invention have large magnetic permeability of the underlying soft magnetic film, and can obtain a sufficient reproduction output. In the media K4 and K5 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media K2, K3 and K9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. In the media K6 and K7 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media K4 and K5 of the present invention.
2, 60% of the reproduction output of K3 and K9, which is still sufficient as the absolute value of the reproduction output. However, in the case of the medium K8 of the present invention, since the magnetic permeability of the underlying soft magnetic film is too small, a sufficient reproduction output cannot be obtained.

From the above, from the viewpoint of the durability of the output signal with respect to the external magnetic field, it is necessary to use the media K2 to K9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetization film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

[Embodiment 11] In Example 1, Fe _{84.9 was used.}
FeT instead of Si _9.6 Al _5.5 (wt%) target
A medium was produced in the same manner as in Example 1 using an aN target. The media manufactured in the same manner as in Example 1 were replaced with the conventional media L1 and LL1 and the media L of the present invention, respectively, in the same manner as in Example 1.
2, L3, L4, L5, L6, L7, L8, and L9. The magnetic permeability of the FeTaN film formed at each substrate temperature was measured. FIG. 33 shows the values of the respective magnetic permeability.

The conventional media L1, LL1 and the present invention medium L2
The experiments of recording and reproduction of L9 to L9 were performed under the same recording and reproduction conditions as in Example 1.

First, in order to examine the stability of the recording magnetization with respect to an external magnetic field, a signal is recorded on the conventional media L1, LL1 and the media L2 to L9 of the present invention with a single pole head, and then a DC magnetic field is applied to the media by a Helmholtz coil. The voltage was applied in the range of 1 to 30 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. FIG. 34 shows the result.
Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 34, the conventional medium L1,
LL1 has good soft magnetic properties of the underlying soft magnetic film, has a sufficiently high magnetic permeability, and has a sufficiently small coercive force, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the media L2 to L9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the entire film is large, it is difficult for external magnetic flux to concentrate on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. Further, in the case of the conventional medium LL1, the ratio of the initial coercive force to the coercive force of the entire film becomes smaller because the thickness of the underlying soft magnetic film is larger than that of the medium L2 of the present invention. It is considered that it became smaller than L2 and became weak against an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
As described above, by setting the thickness of the underlying soft magnetic film to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 35 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 35, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media L1, LL1 and the media L2, L3, L9 of the present invention have a large magnetic permeability of the underlying soft magnetic film, and can obtain a sufficient reproduction output. In the media L4 and L5 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media L2, L3 and L9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. In the media L6 and L7 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media L4 and L5 of the present invention.
2, 60% of the reproduction output of L3 and L9, and it can be said that the absolute value of the reproduction output is still sufficient. However, in the case of the medium L8 of the present invention, since the magnetic permeability of the underlying soft magnetic film is too small, a sufficient reproduction output cannot be obtained.

From the above, from the viewpoint of the durability of the output signal to the external magnetic field, it is necessary to use the media L2 to L9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetization film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

[Example 12] In Example 2, Fe _{84.9 was used.}
FeT instead of Si _9.6 Al _5.5 (wt%) target
A medium was produced in the same manner as in Example 2 using an aN target. A medium manufactured in the same manner as in Example 2 was manufactured in the same manner as in Example 2 except that the conventional medium M1, MM1, and the medium M of the present invention were used.
2, M3, M4, M5, M6, M7, M8, M9.

The magnetic permeability of the FeTaN film formed at each substrate temperature was measured. FIG. 36 shows the values of the respective magnetic permeability.

Conventional media M1, MM1 and media M2 of the present invention
Experiments of recording and reproduction of M9 to M9 were performed under the same recording and reproduction conditions as in Example 1.

First, in order to examine the stability of the recording magnetization with respect to an external magnetic field, signals were recorded on the conventional media M1 and MM1 and the media M2 to M9 of the present invention with a single-pole head, and then a DC magnetic field was applied to the media by a Helmholtz coil. The voltage was applied in the range of 1 to 30 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. The result is shown in FIG.
Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 37, the conventional media M1,
MM1 has good soft magnetic properties of the underlying soft magnetic film, has a sufficiently large magnetic permeability, and has a sufficiently small coercive force, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the media M2 to M9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the entire film is large, it is difficult for external magnetic flux to concentrate on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. In addition, in the case of the conventional medium MM1, the ratio of the initial coercive force to the coercive force of the entire film is smaller because the thickness of the underlying soft magnetic film is thicker than that of the medium M2 of the present invention, and the coercive force of the entire film is reduced. It is considered that it became smaller than M2 and became weak to an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
As described above, by setting the thickness of the underlying soft magnetic film to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 38 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 38, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media M1 and MM1 and the media M2, M3 and M9 of the present invention have large magnetic permeability of the underlying soft magnetic film, and can provide a sufficient reproduction output. In the media M4 and M5 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media M2, M3 and M9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. Since the mediums M6 and M7 of the present invention have smaller magnetic permeability of the underlying soft magnetic film than the mediums M4 and M5 of the present invention, the reproduction output is further reduced.
It is about 60% of the reproduction output of M2, M3 and M9, and it can be said that it is still sufficient as the absolute value of the reproduction output. However, in the case of the medium M8 of the present invention, since the magnetic permeability of the underlying soft magnetic film is too small, a sufficient reproduction output cannot be obtained.

From the above, from the viewpoint of the durability of the output signal with respect to the external magnetic field, it is necessary to use the media M2 to M9 of the present invention, but if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetization film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

[Example 13] In Example 3, Fe _{84.9 was used.}
FeT instead of Si _9.6 Al _5.5 (wt%) target
A medium was produced in the same manner as in Example 1 using an aN target. The media manufactured in the same manner as in Example 1 were replaced with the conventional media N1, NN1, and the medium N of the present invention, respectively.
2, N3, N4, N5, N6, N7, N8, and N9.

The magnetic permeability of the FeTaN film formed at each substrate temperature was measured. FIG. 39 shows the values of the respective magnetic permeability.

Conventional media N1, NN1 and media N2 of the present invention
Experiments of recording and reproduction of N9 to N9 were performed under the same recording and reproduction conditions as in Example 1. First, in order to examine the stability of the recording magnetization with respect to an external magnetic field, a signal is recorded on the conventional media N1, NN1 and the media N2 to N9 of the present invention with a single-pole head, and then a DC magnetic field is applied to the media by a Helmholtz coil.
The voltage was applied in the range of 0 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. The result is shown in FIG. Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 40, the conventional medium N1,
NN1 has good soft magnetic properties of the underlying soft magnetic film, has sufficiently large magnetic permeability, and has a sufficiently small coercive force, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the media N2 to N9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the entire film is large, it is difficult for the magnetic flux from the outside to concentrate on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. Also, in the case of the conventional medium NN1, the ratio of the initial coercive force to the coercive force of the entire film is smaller because the thickness of the underlying soft magnetic film is larger than that of the medium N2 of the present invention. It is considered that it became smaller than N2 and became weak against an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
As described above, by setting the thickness of the underlying soft magnetic film to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 41 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 41, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media N1, NN1 and the media N2, N3, N9 of the present invention have large magnetic permeability of the underlying soft magnetic film, and can obtain a sufficient reproduction output. In the media N4 and N5 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media N2, N3 and N9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. In the media N6 and N7 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media N4 and N5 of the present invention.
2, 60% of the reproduction output of N3 and N9, which is still sufficient as the absolute value of the reproduction output. However, in the case of the medium N8 of the present invention, since the magnetic permeability of the underlying soft magnetic film is too small, a sufficient reproduction output cannot be obtained.

From the above, from the viewpoint of the durability of the output signal with respect to the external magnetic field, it is necessary to use the media N2 to N9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetic film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

[Embodiment 14] In the eleventh embodiment, the FeT
A medium was produced in the same manner as in Example 11, except that an FeTaNTaZr target was used instead of the aN target. T
Addition of aZr has an effect of making crystal grains fine. A medium prepared in the same manner as in Example 11 was prepared according to Example 11,
Conventional media P1, PP1, present media P2, P
3, P4, P5, P6, P7, P8, and P9.

FeTaNTa films formed at each substrate temperature
The magnetic permeability of the Zr film was measured. FIG. 42 shows the values of each magnetic permeability.
Shown in

Conventional media P1, PP1 and media P2 of the present invention
The recording / reproducing experiments P9 to P9 were performed under the same recording / reproducing conditions as in Example 1.

First, in order to examine the stability of recording magnetization with respect to an external magnetic field, signals were recorded on the conventional media P1, PP1 and the media P2 to P9 of the present invention with a single pole head, and then a DC magnetic field was applied to the media by a Helmholtz coil. The voltage was applied in the range of 1 to 30 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. FIG. 43 shows the result.
Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 43, the conventional media P1,
PP1 has good soft magnetic properties of the underlying soft magnetic film, has sufficiently large magnetic permeability, and has a sufficiently small coercive force, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the media P2 to P9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the entire film is large, it is difficult for the magnetic flux from the outside to concentrate on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. In addition, in the case of the conventional medium PP1, the ratio of the initial coercive force to the coercive force of the entire film is smaller because the thickness of the underlying soft magnetic film is thicker than that of the medium P2 of the present invention, and the coercive force of the entire film is reduced. It is considered that it became smaller than P2 and became weak against an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
As described above, by setting the thickness of the underlying soft magnetic film to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, the reproduction output was measured. FIG. 44 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 44, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media P1 and PP1, and the media P2, P3 and P9 of the present invention have a large magnetic permeability of the underlying soft magnetic film, and can obtain a sufficient reproduction output. In the media P4 and P5 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media P2, P3 and P9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. In the media P6 and P7 of the present invention, since the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than those of the media P4 and P5 of the present invention, the reproduction output is further reduced.
2, 60% of the reproduction output of P3 and P9, and it can be said that the absolute value of the reproduction output is still sufficient. However, in the case of the medium P8 of the present invention, the reproduction output cannot be sufficiently obtained because the magnetic permeability of the underlying soft magnetic film is too small.

From the above, from the viewpoint of the durability of the output signal to the external magnetic field, it is necessary to use the media P2 to P9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetic film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

[Embodiment 15] In the twelfth embodiment, the FeT
A medium was produced in the same manner as in Example 12, except that a FeTaNTiMo target was used instead of the aN target. T
Addition of iMo has an effect of making crystal grains fine. A medium prepared in the same manner as in Example 12 was prepared according to Example 12,
Conventional media Q1, QQ1, inventive media Q2, Q
3, Q4, Q5, Q6, Q7, Q8, and Q9.

FeTaNTi deposited at each substrate temperature
The magnetic permeability of the Mo film was measured. FIG. 45 shows the values of each magnetic permeability.
Shown in

Conventional media Q1, QQ1 and media Q2 of the present invention
The recording / reproduction experiments of Q9 to Q9 were performed under the same recording / reproduction conditions as in Example 1.

First, in order to examine the stability of recording magnetization with respect to an external magnetic field, a signal was recorded on the conventional media Q1, QQ1 and the media Q2 to Q9 of the present invention with a single pole head, and then a DC magnetic field was applied to the media by a Helmholtz coil. The voltage was applied in the range of 1 to 30 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. The result is shown in FIG.
Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 46, the conventional media Q1,
QQ1 has an excellent soft magnetic property of the underlying soft magnetic film, has sufficiently high magnetic permeability, and has a sufficiently small coercive force, so that the output starts to decrease with an external magnetic field of 4 Oe. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the media Q2 to Q9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the whole film is large, it is difficult for external magnetic flux to concentrate on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. Further, in the case of the conventional medium QQ1, the ratio of the initial coercive force to the coercive force of the entire film is smaller because the thickness of the underlying soft magnetic film is larger than that of the medium Q2 of the present invention. It is considered that it became smaller than Q2 and became weak to an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
As described above, by setting the thickness of the underlying soft magnetic film to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, a reproduction output was measured. FIG. 47 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 47, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media Q1, QQ1 and the media Q2, Q3, Q9 of the present invention have a large magnetic permeability of the underlying soft magnetic film, and can obtain a sufficient reproduction output. In the media Q4 and Q5 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media Q2, Q3 and Q9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. Since the mediums Q6 and Q7 of the present invention have smaller magnetic permeability of the underlying soft magnetic film than the mediums Q4 and Q5 of the present invention, the reproduction output is further reduced.
2, 60% of the reproduction output of Q3 and Q9, which is still sufficient as the absolute value of the reproduction output. However, in the case of the medium M8 of the present invention, since the magnetic permeability of the underlying soft magnetic film is too small, a sufficient reproduction output cannot be obtained.

From the above, from the viewpoint of the durability of the output signal with respect to the external magnetic field, it is necessary to use the media Q2 to Q9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetic film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

[Embodiment 16] In the embodiment 13, the FeT
A medium was produced in the same manner as in Example 13 except that an FeTaNZrNb target was used instead of the aN target. Z
The addition of rNb has an effect of making crystal grains fine. A medium prepared in the same manner as in Example 13 was prepared according to Example 13,
Conventional media R1, RR1, media R2, R
3, R4, R5, R6, R7, R8, and R9.

FeTaNZr formed at each substrate temperature
The magnetic permeability of the Nb film was measured. FIG. 48 shows the values of each magnetic permeability.
Shown in

Conventional media R1, RR1 and media R2 of the present invention
Experiments for recording and reproduction of R9 to R9 were performed under the same recording and reproduction conditions as in Example 1.

First, in order to examine the stability of the recording magnetization with respect to an external magnetic field, a signal was recorded on the conventional media R1, RR1 and the media R2 to R9 of the present invention with a single pole head, and then a DC magnetic field was applied to the media by a Helmholtz coil. The voltage was applied in the range of 1 to 30 Oe, and the reproduction output before applying the magnetic field and the reproduction output after applying the magnetic field were compared. The result is shown in FIG.
Here, the reproduction output after applying the magnetic field with respect to the reproduction output before applying the magnetic field is shown as a percentage.

As can be seen from FIG. 49, the conventional medium R1,
In RR1, the output starts to decrease with an external magnetic field of 4 Oe because the soft magnetic characteristics of the underlying soft magnetic film are good, the magnetic permeability is sufficiently large, and the coercive force is sufficiently small. And the coercive force is made relatively large, so that the output of any medium does not decrease to an external magnetic field of 20 Oe. At this time, the value of the coercive force is distributed in the range of 2 Oe to 30 Oe, but the coercive force of each film when only 10 nm is formed (referred to as the initial coercive force for convenience). When the coercive force of the entire film is 2 Oe or more, it can be seen that the initial coercive force shows a value of 30 Oe or more. Generally, the coercive force of the initial layer of film growth is large, but the coercive force of the initial layer of growth can increase the coercive force of the entire film.

In the case of the media R2 to R9 of the present invention, since the magnetic permeability of the underlying soft magnetic film is small and the coercive force of the entire film is large, it is difficult for external magnetic flux to be concentrated on the main pole of the single pole head. Thus, a perpendicular two-layer medium resistant to an external magnetic field could be obtained. Further, in the case of the conventional medium RR1, the ratio of the initial coercive force to the coercive force of the entire film is smaller because the thickness of the underlying soft magnetic film is larger than that of the medium R2 of the present invention. It is considered that it became smaller than R2 and became weak to an external magnetic field. From the above, the magnetic permeability of the underlying soft magnetic film is 1000 or less, the coercive force of the entire film is 2 Oe to 30 Oe, and the initial coercive force is 30 Oe.
As described above, by setting the thickness of the underlying soft magnetic film to 300 nm or less, a perpendicular two-layer medium resistant to an external magnetic field can be obtained.

Next, a reproduction output was measured. FIG. 50 shows the measurement results of the recording density dependence of the reproduction output. As can be seen from FIG. 50, the magnitude of the reproduction output increases as the magnetic permeability of the underlying soft magnetic film increases. The conventional media R1, RR1, and the media R2, R3, R9 of the present invention have a large magnetic permeability of the underlying soft magnetic film, and can obtain a sufficient reproduction output. In the media R4 and R5 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media R2, R3 and R9 of the present invention. It is about 80%, which is still sufficient as the absolute value of the reproduction output. In the media R6 and R7 of the present invention, the magnitude of the magnetic permeability of the underlying soft magnetic film is smaller than that of the media R4 and R5 of the present invention.
2, 60% of the reproduction output of R3 and R9, which is still sufficient as the absolute value of the reproduction output. However, in the case of the medium R8 of the present invention, since the magnetic permeability of the underlying soft magnetic film is too small, a sufficient reproduction output cannot be obtained.

From the above, from the viewpoint of the durability of the output signal with respect to the external magnetic field, it is necessary to use the media R2 to R9 of the present invention. However, if the magnetic permeability of the underlying soft magnetic film is too low, the reproduction output will not decrease. Invite. For this reason, the magnetic permeability of the underlying soft magnetic film needs to be 50 or more. From the viewpoint of reproduction output, the magnetic permeability of the underlying soft magnetic film is preferably 50 or more and 100 or less, more preferably 50 or more and 500 or less, and even more preferably 50 or more and 1000 or less.

The durability of the output signal with respect to the external magnetic field is generated by the interaction between the main magnetic pole of the single pole head and the underlying soft magnetic film, and therefore does not depend much on the thickness of the perpendicular magnetic film. Therefore, the same result is obtained even if the thickness of the perpendicular magnetization film is changed to some extent.

In the above embodiments and examples, the recording medium is described as a two-layer perpendicular recording medium. However, the present invention has a technical idea of using at least a perpendicular magnetization film and a soft magnetic film having a small magnetic permeability. If there is, it is needless to say that the recording medium may have a plurality of perpendicular recording layers.

[0173] According to the present invention described above, without the film with the lower soft magnetic film excellent soft magnetic characteristics, the magnetic permeability of the lower soft magnetic film is made smaller than the conventional, more than 50 100
0 or less, 50 or more and 500 or less, or 50 or more and 100 or less
And the overall coercive force of the underlying soft magnetic film is 2 (Oe).
Or by a 30 (Oe) or less, to slow down the reactivity of the magnetization of the soft magnetic underlayer film to an external magnetic field, child suppress concentration of magnetic flux of the external magnetic field to the main magnetic pole of a perpendicular magnetic head
Can be. Therefore , demagnetization or demagnetization of the magnetization recorded in the perpendicular recording layer hardly occurs, and the stability of the recorded magnetization with respect to an external magnetic field can be improved .

[Brief description of the drawings]

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

FIG. 2 is a schematic cross-sectional view illustrating a form of a perpendicular magnetic recording medium according to a first embodiment of the present invention.

FIG. 3 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 1 of the present invention.

FIG. 4 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 1 of the present invention.

FIG. 5 is a graph showing a recording density dependency of an output in the first embodiment of the present invention.

FIG. 6 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 2 of the present invention.

FIG. 7 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 2 of the present invention.

FIG. 8 is a graph showing a recording density dependency of an output in the second embodiment of the present invention.

FIG. 9 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 3 of the present invention.

FIG. 10 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 3 of the present invention.

FIG. 11 is a graph showing a recording density dependency of an output in a third embodiment of the present invention.

FIG. 12 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 4 of the present invention.

FIG. 13 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 4 of the present invention.

FIG. 14 is a graph showing the recording density dependency of the output in Example 4 of the present invention.

FIG. 15 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 5 of the present invention.

FIG. 16 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 5 of the present invention.

FIG. 17 is a graph showing recording density dependency of output in Example 5 of the present invention.

FIG. 18 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 6 of the present invention.

FIG. 19 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 6 of the present invention.

FIG. 20 is a graph showing the recording density dependency of the output in Example 6 of the present invention.

FIG. 21 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 7 of the present invention.

FIG. 22 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 7 of the present invention.

FIG. 23 is a graph showing the recording density dependency of the output in Example 7 of the present invention.

FIG. 24 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 8 of the present invention.

FIG. 25 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 8 of the present invention.

FIG. 26 is a graph showing the recording density dependency of output in Example 8 of the present invention.

FIG. 27 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 9 of the present invention.

FIG. 28 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 9 of the present invention.

FIG. 29 is a graph showing recording density dependency of output in Example 9 of the present invention.

FIG. 30 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 10 of the present invention.

FIG. 31 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 10 of the present invention.

FIG. 32 is a graph showing recording density dependence of output in Example 10 of the present invention.

FIG. 33 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 11 of the present invention.

FIG. 34 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 11 of the present invention.

FIG. 35 is a graph showing the recording density dependency of the output in Example 11 of the present invention.

FIG. 36 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 12 of the present invention.

FIG. 37 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 12 of the present invention.

FIG. 38 is a graph showing recording density dependency of output in Example 12 of the present invention.

FIG. 39 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 13 of the present invention.

FIG. 40 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 13 of the present invention.

FIG. 41 is a graph showing recording density dependency of output in Example 13 of the present invention.

FIG. 42 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 14 of the present invention.

FIG. 43 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 14 of the present invention.

FIG. 44 is a graph showing the recording density dependence of the output in Example 14 of the present invention.

FIG. 45 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 15 of the present invention.

FIG. 46 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 15 of the present invention.

FIG. 47 is a graph showing the recording density dependence of the output in Example 15 of the present invention.

FIG. 48 is a table showing values of magnetic permeability, overall coercive force, initial coercive force, and film thickness in Example 16 of the present invention.

FIG. 49 is a graph showing a ratio between an external magnetic field and a reproduction output before and after application of a magnetic field in Example 16 of the present invention.

FIG. 50 is a graph showing the recording density dependency of the output in Example 16 of the present invention.

FIG. 51 is a schematic sectional view showing a form of a conventional perpendicular magnetic recording medium.

FIG. 52 is a schematic sectional view showing a form of a magnetic head and a magnetic medium of a conventional perpendicular magnetic recording apparatus.

[Explanation of symbols]

10 perpendicular magnetic recording medium 12 substrate 16 FeSiAl soft magnetic film 18 Co ₇₈ Cr ₁₉ PtLaLu perpendicular magnetization film 20 perpendicular magnetic recording medium 22 small soft magnetic film 28 perpendicularly magnetized film of the substrate 24 permeability 50,61 perpendicular magnetic recording medium 52 and 63 Soft magnetic backing layer 54, 64 Perpendicular magnetization film 56, 62 Substrate 65 Perpendicular magnetic head 66 Main pole 67 Coil

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-183011 (JP, A) JP-A-6-139542 (JP, A) JP-A-57-36435 (JP, A) JP-A-2- 123705 (JP, A) JP-A-4-12508 (JP, A) JP-A-8-213235 (JP, A) JP-A-2-103715 (JP, A) JP-A-59-218626 (JP, A) JP-A-63-39123 (JP, A) JP-A-3-224122 (JP, A) JP-A-10-228620 (JP, A) JP-A-11-149628 (JP, A) JP-A-11-238223 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G11B 5/667

Claims (14)

(57) [Claims] 1. A soft magnetic underlayer film and a perpendicular magnetic recording medium that is a combination of perpendicular magnetization film, the permeability of the lower soft magnetic film is Ri der 50 to 1000, of the lower soft magnetic film
A perpendicular magnetic recording medium having an overall coercive force of 2 (Oe) or more and 30 (Oe) or less . 2. A soft magnetic underlayer film and a perpendicular magnetic recording medium that is a combination of perpendicular magnetization film, the permeability of the lower soft magnetic film is Ri der 50 to 500, all of the lower soft magnetic film
A perpendicular magnetic recording medium , wherein the coercive force of the body is 2 (Oe) or more and 30 (Oe) or less . 3. A soft magnetic underlayer film and a perpendicular magnetic recording medium that is a combination of perpendicular magnetization film, the permeability of the lower soft magnetic film is Ri der 50 or more and 100 or less, the total of the lower soft magnetic film
A perpendicular magnetic recording medium , wherein the coercive force of the body is 2 (Oe) or more and 30 (Oe) or less . 4. The perpendicular magnetic recording medium according to claim 1 , wherein the underlying soft magnetic film of the underlying soft magnetic film has a thickness of 10 nm from the substrate side. A perpendicular magnetic recording medium having a magnetic force of 30 (Oe) or more. 5. A perpendicular magnetic recording medium according to any one of claims 1 to 4, the perpendicular magnetic recording medium, wherein the thickness of the lower soft magnetic film is 300nm or less. 6. The perpendicular magnetic recording medium according to any one of claims 1 to 5, a perpendicular magnetic recording medium, wherein the material of the lower soft magnetic film is a FeSiAl alloy. 7. The perpendicular magnetic recording medium according to any one of claims 1 to 5, the material of the lower soft magnetic film is _{Fe 84.9 Si x Al 15.1-x} (8.0 ≦ X ≦ 12.0 A) a perpendicular magnetic recording medium; 8. The perpendicular magnetic recording medium according to any one of claims 1 to 5, a vertical, wherein the material of the lower soft magnetic film is a _{Fe 84.9 Si 9.6 Al 5.5 (wt} %) Magnetic recording medium. The perpendicular magnetic recording medium according to any one of 9. claims 1 to 8, and the lower soft magnetic film material element M is added to the alloy, Ta as the element M, T
A perpendicular magnetic recording medium comprising any two elements of i, Zr, Mo, and Nb. 10. The perpendicular magnetic recording medium according to any one of claims 1 to 5, a perpendicular magnetic recording medium, wherein the material of the lower soft magnetic film is FeTaN. 11. The perpendicular magnetic recording medium according to any one of claims 1 to 10, the material of the perpendicular magnetization film is CoCrR alloy, Pt as the R, Ta, L
A perpendicular magnetic recording medium comprising any three of a, Lu, Pr, and Sr. 12. A magnetic recording apparatus for recording information on a perpendicular magnetic recording medium, wherein the perpendicular magnetic recording medium has a base soft magnetic film and a perpendicular magnetic film sequentially laminated on a substrate, permeability Ri der 50 or more and 100 or less, before
The overall coercive force of the underlying soft magnetic film is 2 (Oe) or more and 30
(Oe) A magnetic recording device characterized by the following . 13. The magnetic recording apparatus according to claim 12 , wherein the base soft magnetic film is made of an alloy in which an element M is added, and the element M is Ta, Ti, Zr, Mo, or Nb.
A magnetic recording device containing any two of the above elements. 14. The magnetic recording apparatus according to claim 12 , wherein a material of the perpendicular magnetization film is a CoCrR alloy,
A magnetic recording apparatus, wherein R includes any three elements of Pt, Ta, La, Lu, and PrSr.