JP2006228424A - Vertical magnetic recording medium, recording method, and magnetic storage apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertical magnetic recording medium wherein a recording magnetic field is heightened and a gradient of the recording magnetic field is made steep by suppressing spread of a magnetic flux from a recording head and high density recording is made possible and to provide a recording method and a magnetic storage apparatus. <P>SOLUTION: The vertical magnetic recording medium is constituted of a substrate 11 and a soft magnetic backing layer 12, a magnetic flux control layer 101, a recording layer 16, a protective film 18 and a lubricant layer 19 which are sequentially layered on the substrate 11. The magnetic flux control layer 101 is composed of a superconducting material, for example, an oxide superconducting body, Nb<SB>3</SB>Ge, and Nb<SB>3</SB>Al having 90 to 125°K superconducting critical temperature. By heating a part of the magnetic flux control layer 101 by a light beam LB from a laser light source 117 to change the part in a normal conducting state, a magnetic flux is concentrated in only the region in the normal conducting state and the magnetic flux passing through the magnetic flux control layer 101 magnetizes the recording layer 16. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a perpendicular magnetic recording medium, a recording method, and a magnetic storage device, and more particularly to a perpendicular magnetic recording medium, a recording method, and a magnetic storage device capable of high-density recording.

  Due to the rapid technological development of magnetic storage devices, a practical machine with a surface recording density of 100 Gbit / in 2 is soon to be commercialized in the in-plane recording method for recording in the in-plane direction of the magnetic recording medium. However, the thermal stability of recorded magnetization has become a problem as the size of the recording unit is reduced in the in-plane recording method at the boundary of 100 Gbit / in 2. In the future, it is said that further improvement up to 250 Gbit / in 2 is possible for practical use, but the limit of the surface recording density is almost reached.

  On the other hand, in the perpendicular recording method for recording in the perpendicular direction of the magnetic recording medium, the thermal recording stability can be ensured by providing an appropriate thickness even if the size of the recording unit is miniaturized. It is expected that it can be improved to the bit / square inch range.

  As the perpendicular magnetic recording medium, a so-called two-layer perpendicular magnetic recording medium in which a soft magnetic backing layer is provided between the recording layer and the substrate is the mainstream. The two-layer perpendicular magnetic recording medium has a function of strengthening the recording magnetic field from the main magnetic pole of the recording head by the mirror image effect of the soft magnetic underlayer, and concentrating the recording magnetic field spatially to increase the gradient of the recording magnetic field.

  However, since the soft magnetic backing layer is disposed so as to face the main pole, the magnetic flux emitted from the main pole spreads toward the soft magnetic backing layer and spreads on the surface of the recording layer. This causes a problem that a large recording bit cannot be formed, and a high recording density cannot be achieved.

Further, as the recording density is increased, the medium noise increases as the reproduction output decreases, and therefore, the study of improving the S / N is underway. Specifically, it is known that it is necessary to refine, isolate, control the orientation and improve the crystallinity of the magnetic particles in the recording layer. The magnetic particles of the recording layer are formed on, for example, a nonmagnetic intermediate layer. However, since the recording layer is affected by the crystal orientation and crystallinity of the nonmagnetic intermediate layer, the design of the nonmagnetic intermediate layer is important.
JP 2002-163819 A JP-A-3-130904 JP-A-6-295431 Japanese Patent Laid-Open No. 10-3644 JP 2001-134918 A

  However, for example, if the film thickness is increased in order to improve the crystallinity of the nonmagnetic intermediate layer, the crystallinity of the recording layer is improved, but the spacing between the recording head and the soft magnetic backing layer increases and the magnetic flux spreads. This causes the problem.

  Accordingly, it is a general object of the present invention to provide a novel and useful perpendicular magnetic recording medium, a recording method, and a magnetic storage device that solve the above-described problems.

  More specific problems of the present invention include a perpendicular magnetic recording medium capable of high-density recording, a recording method, which suppresses the spread of magnetic flux from the recording head, increases the recording magnetic field, and makes the gradient of the recording magnetic field steep. And providing a magnetic storage device.

  According to one aspect of the present invention, a magnetic backing layer and a recording layer provided above the soft magnetic backing layer are provided, and magnetic flux from the recording head flows through the recording layer to the soft magnetic backing layer. A perpendicular magnetic recording medium in which a recording layer is magnetized, having a magnetic flux control layer including a superconducting material between the soft magnetic underlayer and the recording layer, and being part of the superconducting magnetic flux control layer There is provided a perpendicular magnetic recording medium characterized by forming a normal conduction region and allowing the magnetic flux to flow therethrough.

  According to the present invention, since the magnetic flux control layer is in a superconducting state and is a complete diamagnetic material, the magnetic flux from the recording head is interrupted in the magnetic flux control layer. By heating a part of the magnetic flux control layer to change to the normal state, the magnetic flux can pass only through the normal state, so that the magnetic flux is concentrated in that region, Magnetic flux can be concentrated on the recording layer in contact therewith. Therefore, erasure of adjacent tracks due to the spread of magnetic flux can be prevented, and the track density can be improved. Also, the width of the magnetization transition region can be narrowed in the longitudinal direction of the track, and the linear recording density can be improved. As a result, a perpendicular magnetic recording medium with a high recording density can be realized.

  According to another aspect of the present invention, a magnetic storage comprising the above-described perpendicular magnetic recording medium, a heating means for selectively heating the surface of the perpendicular recording medium, and a recording means for recording information on the recording layer. The apparatus is configured to heat a part of the magnetic flux control layer in which the heating unit is in a superconducting state during recording to change to a normal conducting state, and A magnetic storage device is provided, wherein information is recorded on a recording layer by passing a magnetic flux through an area.

  According to the present invention, at the time of recording, the heating means heats a part of the magnetic flux control layer in the superconducting state to change to the normal conducting state, and the part that has become the normal conducting state by the recording means. By passing the magnetic flux through this area, the magnetic flux can be concentrated on the recording layer in contact with the area. Therefore, erasure of adjacent tracks due to the spread of magnetic flux can be prevented, and the track density can be improved. Also, the width of the magnetization transition region can be narrowed in the longitudinal direction of the track, and the linear recording density can be improved. As a result, a high-density magnetic storage device can be realized.

  According to the present invention, by providing a magnetic flux control layer between the soft magnetic backing layer and the recording layer, the spread of the magnetic flux from the recording head is suppressed, the recording magnetic field is increased and the gradient of the recording magnetic field is steep, A perpendicular magnetic recording medium capable of high-density recording, a recording method, and a magnetic storage device can be realized.

  Hereinafter, the present invention will be described in detail with reference to the drawings as necessary.

(First embodiment)
First, a perpendicular magnetic recording medium according to the first embodiment of the present invention, in which a substantially columnar magnetic flux slit layer made of a soft magnetic material is provided between a soft magnetic backing layer and a recording layer, will be described.

  FIG. 1 is a schematic cross-sectional view of a perpendicular magnetic recording medium according to the first embodiment of the present invention. Referring to FIG. 1, a perpendicular magnetic recording medium 10 according to the present embodiment includes a substrate 11, a soft magnetic backing layer 12, a seed layer 13, a magnetic flux slit layer 14, a nonmagnetic intermediate layer 15 on the substrate 11. The recording layer 16, the protective film 18, and the lubricating layer 19 are sequentially stacked.

  The substrate 11 is composed of, for example, a crystallized glass substrate, a tempered glass substrate, an Si substrate, an aluminum alloy substrate, and the like. When the perpendicular magnetic recording medium 10 is in a tape shape, polyester (PET), polyethylene naphthalate (PEN), A film such as polyimide (PI) having excellent heat resistance can be used.

  The soft magnetic backing layer 12 has, for example, a thickness of 50 nm to 2 μm, and at least one selected from Fe, Co, Ni, Al, Si, Ta, Ti, Zr, Hf, V, Nb, C, and B An amorphous or microcrystalline alloy containing these elements, or a laminated film of these alloys. A soft magnetic material having a saturation magnetic flux density Bs of 1.0 T or more is preferable in that the recording magnetic field can be concentrated. For example, FeSi, FeAlSi, FeTaC, CoNbZr, CoCrNb, NiFeNb, etc. can be used. The soft magnetic backing layer 12 is formed by a plating method, a sputtering method, a vapor deposition method, a CVD method (chemical vapor deposition method), or the like. The soft magnetic backing layer 12 is for absorbing almost all the magnetic flux from the recording head, and it is preferable that the product of the saturation magnetic flux density Bs and the film thickness is larger for saturation recording. The soft magnetic underlayer 12 preferably has a high high-frequency magnetic permeability in terms of writability at a high transfer rate.

  The seed layer 13 has a thickness of, for example, 1.0 nm to 10 nm, and is selected from Ta, C, Mo, Ti, W, Re, Os, Hf, Mg, and alloys thereof. The crystallinity of the magnetic flux slit layer 14 formed thereon can be enhanced, the crystal orientation or crystal growth relationship between the magnetic flux slit layer 14 and the soft magnetic underlayer 12 can be cut, and further the magnetic interaction can be cut. . Note that the seed layer may or may not be provided.

  The magnetic flux slit layer 14 has a thickness of 0.5 nm to 20 nm, for example, and is made of a soft magnetic material. In the magnetic flux slit layer 14, the boundary between the soft magnetic particles of the soft magnetic material and the adjacent soft magnetic particles is composed of a low density body of the soft magnetic material. The soft magnetic particles extend perpendicular to the film surface, the bottom portion grows from the underlying seed layer, and the surface has a substantially columnar structure reaching the nonmagnetic intermediate layer 15. In the boundary portion, an inert gas such as He, Ne, Ar, Kr, or Xe is taken into the soft magnetic material constituting the soft magnetic particles to form an amorphous state. Therefore, the boundary part has lost soft magnetism, or the saturation magnetic flux density is lower than that of soft magnetic particles. The boundary portion may contain oxygen and nitrogen in addition to the inert gas, and oxygen and nitrogen may form a compound with the soft magnetic material.

  The average particle diameter of the soft magnetic particles is preferably set to 3 nm to 10 nm (the diameter of a circle corresponding to the cross-sectional area of the soft magnetic particles in the sectional view cut in the film surface direction) is 3 nm to 10 nm. The average gap between the magnetic particles is preferably set to 0.5 nm to 3 nm.

  The soft magnetic material used for the magnetic flux slit layer 14 is formed of a material mainly containing at least one selected from Co, Fe, Ni, a Co alloy, a Fe alloy, and a Ni alloy. Furthermore, as an additive component, any one of the group consisting of Al, Ta, Ag, Cu, Pb, Si, B, Zr, Cr, Ru, Re, Nb, and C may be further included. For example, the soft magnetic material is preferably CoNbZr, CoZrTa, FeC, FeC, NiFe, FeTaC, FeCoAl, FeC film / C artificial lattice film, or the like.

  When the nonmagnetic intermediate layer 15 described later has an hcp structure, the magnetic flux slit layer 14 preferably has an hcp structure or an fcc structure, and the (001) plane of the hcp structure or the (111) plane of the fcc structure is a nonmagnetic intermediate. It is preferable to be an interface with the layer 15. The magnetic flux slit layer 14 can be epitaxially grown, and the crystallinity can be improved.

  Further, since the adjacent soft magnetic particles of the magnetic flux slit layer 14 are separated by the boundary portion, the crystal particles formed in the nonmagnetic intermediate layer 15 are similarly separated and formed. As a result, since the magnetic particles of the recording layer 16 formed on the nonmagnetic intermediate layer 15 are also separated and grown in the same manner, physical separation of the magnetic particles is promoted, and magnetic interaction between adjacent magnetic particles is promoted. Can be reduced.

  The magnetic slit anisotropy is preferably larger in the in-plane magnetic anisotropy than the perpendicular magnetic anisotropy. When the perpendicular magnetic anisotropy is large, noise increases due to fluctuation of the magnetization component in the direction perpendicular to the film surface during reproduction.

  The magnetic flux slit layer 14 is formed by a vacuum process such as sputtering or vacuum deposition. Specifically, a predetermined film thickness is formed using a sputtering method, for example, a DC magnetron sputtering method, using an inert gas alone or a mixed gas such as He, Ne, Ar, Kr, and Xe. The degree of vacuum during film formation is preferably set to 1 Pa to 8 Pa. When the pressure is lower than 1 Pa, it is difficult to form a structure composed of the soft magnetic particles and the boundary. When the pressure exceeds 8 Pa, the volume ratio of the soft magnetic particles becomes small, and the magnetic flux cannot be sufficiently passed. Further, 2 Pa or more is preferable from the viewpoint of more complete magnetic separation from adjacent soft magnetic particles, and 6 Pa or less is preferable from the viewpoint of good epitaxial growth of the recording layer 16. The substrate temperature during film formation is preferably set to 0 ° C. to 150 ° C. (especially 15 ° C. to 80 ° C.). In terms of promoting the formation of the boundary portion, nitrogen gas or oxygen gas that does not deteriorate the magnetic properties of the soft magnetic particles may be mixed with the atmospheric gas.

  The nonmagnetic intermediate layer 15 has a thickness of 2 nm to 30 nm, for example, and is made of a nonmagnetic material such as Co, Cr, Ru, Re, Ri, Hf, and alloys thereof. Examples of the nonmagnetic intermediate layer 15 include a Ru film, a RuCo film, and a CoCr film, and preferably have an hcp structure. When the recording layer 16 has an hcp structure, it can be epitaxially grown and the crystallinity of the recording layer 16 can be improved.

  The recording layer 16 is a so-called perpendicular magnetization film having an easy axis in the film thickness direction, and is made of Ni, Fe, Co, Ni-based alloy, Fe-based alloy, CoCrTa, CoCrPt, CoCrPt-M having a thickness of 3 nm to 30 nm. It is comprised from either material of the group which consists of a Co type alloy containing. Here, M is selected from B, Mo, Nb, Ta, W, Cu, and alloys thereof. Such a ferromagnetic alloy has a columnar structure. In the case of the hcp structure, the film thickness direction, that is, the growth direction is the (001) plane, and has an easy axis of magnetization in the film thickness direction. Examples of the recording layer 16 include CoCrPtB, CoCrPtTa, and CoCrPtTaNb.

The recording layer 16 further includes at least one element selected from Si, Al, Ta, Zr, Y, and Mg and at least one element selected from O, C, and N. It may be composed of the above-described ferromagnetic alloy columnar crystal grains and a nonmagnetic phase that physically separates adjacent crystal grains. Examples of the recording layer 16 include (CoPt)-(SiO ₂ ), (CoCrPt)-(SiO ₂ ), (CoCrPtB)-(MgO), and the like. Since the magnetic particles form a columnar structure and the non-magnetic phase surrounds the magnetic particles, the magnetic particles are separated from each other, effectively suppressing or cutting the interaction between the magnetic particles and reducing the media noise. be able to.

  The recording layer 16 may be an artificial lattice film such as Co / Pd, CoB / Pd, Co / Pt, or CoB / Pt. The artificial lattice film is formed, for example, by laminating 5 to 30 layers of CoB (thickness: 0.3 nm) / Pd (thickness 0.8 nm) alternately. Since these artificial lattice films have large perpendicular magnetic anisotropy, they are excellent in thermal stability.

  The protective film 18 is formed by a sputtering method, a CVD method, an FCA (Filtered Cathodic Arc) method, or the like, and is made of, for example, amorphous carbon having a thickness of 0.5 nm to 15 nm, hydrogenated carbon, carbon nitride, aluminum oxide, or the like. The

  The lubricating layer 19 is applied by a pulling method, a spin coating method, or the like, and is formed of a lubricant having a thickness of 0.5 nm to 5 nm and a main chain of perfluoropolyether. As the lubricant, for example, ZDol, Z25 (manufactured by Monte Fluos) Z-tetraol, AM3001 (manufactured by Augmont) can be used.

  In the conventional perpendicular magnetic recording medium not provided with the magnetic flux slit layer, the magnetic flux from the magnetic head spreads toward the soft magnetic backing layer during recording, whereas the perpendicular magnetic recording medium of the present embodiment is In this case, the magnetic flux slit layer 14 is formed from a soft magnetic particle having a substantially columnar structure and a non-magnetic boundary, and the magnetic flux passes only through the soft magnetic particle having a high magnetic permeability, so that the magnetic flux is confined only to the soft magnetic particle portion. Thus, the spread of the magnetic flux can be suppressed, and the magnetic flux can be concentrated in the recording layer 16. Therefore, since the recording magnetic field can be increased and the spatial distribution of the recording magnetic field can be made steep, recording can be performed at a high recording density.

  In the perpendicular magnetic recording medium of the present embodiment, since the soft magnetic particles in the magnetic flux seed layer are physically separated, the physical properties of the magnetic particles in the recording layer 16 formed via the non-magnetic intermediate layer 15 are physically separated. Separation is promoted. As a result, magnetic interaction between adjacent magnetic particles can be reduced, and medium noise can be reduced.

  FIG. 2 is a schematic cross-sectional view of a perpendicular magnetic recording medium according to a first modification of the first embodiment. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 2, the perpendicular magnetic recording medium 30 includes a substrate 11, a soft magnetic backing layer 12, a seed layer 13, an underlayer 31, a magnetic flux slit layer 14, a nonmagnetic intermediate layer 15, a recording layer on the substrate 11. 16, a protective film 18, and a lubricating layer 19 are sequentially stacked. The perpendicular magnetic recording medium 30 according to this modification is characterized in that an underlayer 31 is further provided between the seed layer 13 and the magnetic flux slit layer 14.

  The underlayer 31 has a thickness of, for example, 0.5 nm to 20 nm, and is composed mainly of at least one selected from Co, Fe, Ni, a Co alloy, a Fe alloy, and a Ni alloy. Consists of materials. Furthermore, as an additive component, any one of a group consisting of Mo, Cr, Cu, V, Nb, Al, Si, B, C, and Zr may be further included. By functioning as a growth nucleus of the magnetic flux slit layer 14, the crystallinity of the soft magnetic particles of the magnetic flux slit layer 14 can be improved, or isolation can be promoted. Further, by having soft magnetism, the spacing between the recording head and the soft magnetic backing layer can be reduced. For example, the underlayer 31 is formed by a vacuum process such as a sputtering method or a vacuum evaporation method, and is preferably set to an atmospheric gas pressure lower than the atmospheric gas pressure when the magnetic flux slit layer 14 is formed, for example, 2 Pa or less. A high-quality growth nucleus or initial growth layer can be formed.

  According to this modification, the crystallinity of the soft magnetic particles in the magnetic flux slit layer 14 is improved, so that the crystallinity of the magnetic particles in the recording layer 16 formed through the nonmagnetic intermediate layer 15 can be further improved. . As a result, the anisotropic magnetic field of the recording layer 16 can be improved and the coercive force can be improved.

  FIG. 3 is a schematic cross-sectional view of a perpendicular magnetic recording medium according to a second modification of the first embodiment. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 3, the perpendicular magnetic recording medium 35 includes a substrate 11, a soft magnetic backing layer 12, a magnetic flux slit layer 36, a seed layer 13, a nonmagnetic intermediate layer 15, a recording layer 16, and a protective film on the substrate 11. 18 and the lubricating layer 19 are sequentially laminated. The perpendicular magnetic recording medium 35 according to this modification is characterized in that a magnetic flux slit layer 36 is provided in contact with the magnetic underlayer 12.

  The magnetic flux slit layer 36 is substantially the same as the magnetic flux slit layer 14 shown in FIG. The thickness of the magnetic flux slit layer 36 is preferably set in a range of 0.3 nm to 10 nm, and the in-plane anisotropy of the magnetic flux slit layer 36 is approximately the same as the in-plane anisotropy of the soft magnetic backing layer 12 or It is preferable to set it larger than that. The in-plane anisotropy can be increased by reducing the thickness of the magnetic flux slit layer 36, and noise caused by the soft magnetic backing layer 12 such as spike noise can be suppressed. Further, since the magnetic flux slit layer 36 is in contact with the soft magnetic backing layer 12, the spread of magnetic flux on the surface of the soft magnetic backing layer 12 can be effectively suppressed, and the effect of constricting the magnetic flux in the recording layer 16 can be further enhanced. Can be increased.

  Further, since the magnetic slit anisotropy of the magnetic flux slit layer 36 has a larger in-plane magnetic anisotropy than the perpendicular anisotropy, spike noise generated due to fluctuation of the magnetization of the soft magnetic backing layer 12 in the direction perpendicular to the surface during reproduction is further reduced. can do.

  In the perpendicular magnetic recording medium of this modification, in addition to the effect of the perpendicular magnetic recording medium according to the first embodiment, as described above, the effect of constricting the magnetic flux during recording is further enhanced and the soft magnetic underlayer 12 is caused. Noise can be reduced.

  Note that the perpendicular magnetic recording medium of the first embodiment or the first modification may be combined with the second modification.

  Examples according to the present embodiment and comparative examples not according to the present invention are shown below.

[Example 1]
The perpendicular magnetic recording medium according to this example was configured as follows. From the substrate side, glass substrate / soft magnetic backing layer: CoNbZr film (180 nm) / seed layer: Ta film (5 nm) / magnetic flux slit layer: NiFe film (5 nm) / nonmagnetic intermediate layer: Ru film (X nm) / recording layer: (Co ₇₆ Cr ₉ Pt ₁₅ ) 90 vol%-(SiO ₂ ) 10 vol% film (10 nm) / protective film: carbon film (4 nm) / lubricating layer: AM3001 film (1.5 nm). The layers other than the lubrication layer were formed using a sputtering apparatus in an Ar gas atmosphere, the atmospheric gas pressure during the formation of the CoNbZr film and the Ta film was 0.5 Pa, and the atmospheric gas pressure of the NiFe film and the Ru film was 4.0 Pa. In addition, the numerical value in the said parenthesis represents a film thickness, The film thickness X of the Ru film | membrane produced the sample made different from X = 7, 10, 15, 20 nm.

[Example 2]
An underlayer: NiFe film (5 nm) was formed between the seed layer of Example 1: Ta film (5 nm) and the magnetic flux slit layer: NiFe film (5 nm) by further setting the atmospheric gas pressure to 0.5 Pa. Except for this, the procedure was the same as in Example 1.

[Comparative Example 1]
Example 1 Magnetic flux slit layer: The same as Example 1 except that the NiFe film (5 nm) was formed at an atmospheric gas pressure of 0.5 Pa.

  FIG. 4 is a diagram showing the characteristics of the perpendicular magnetic recording media according to Examples 1 and 2 and Comparative Example 1. In the figure, α represents a slope 4π × ΔM / ΔH in the vicinity of the coercive force of the magnetization curve measured by applying a magnetic field in a direction perpendicular to the recording layer, and as α is closer to 1, the magnetic particles are magnetically isolated. Indicates that is progressing.

  Referring to FIG. 4, α is 4.1 to 4.9 in the first comparative example, and 1.7 to 3.1 in the first and second examples. 2 indicates that the magnetic particles are more isolated.

  The normalized coercive force is 0.23 to 0.31 in Comparative Example 1, whereas it is 0.33 to 0.45 in Examples 1 and 2, which is a significant increase. Since the larger the standardized coercive force, the smaller the magnetic interaction between the magnetic particles, Examples 1 and 2 have a smaller magnetic interaction than Comparative Example 1. I understand that As a result, it can be seen that the media noise is significantly reduced in Examples 1 and 2 compared to Comparative Example 1, and the S / Nm is improved. Although not shown, according to the cross-sectional TEM observation of the perpendicular magnetic recording medium of Example 2, almost columnar crystal grains are formed in the Ru film on the NiFe film of the magnetic flux slit layer, and the magnetic particles in the recording layer are further formed. It was confirmed that was formed in isolation.

  When Example 1 is compared with Example 2, Example 2 is larger than Example 1 in terms of S / Nm. In Example 2, since the NiFe film (film thickness 5 nm) formed by setting the atmospheric gas pressure to 0.5 Pa with respect to Example 1 is formed, NiFe as a magnetic flux slit layer formed thereon is formed. It is considered that the crystallinity of the film (atmospheric gas pressure: 4.0 Pa, film thickness 5 nm) was improved, and the crystallinity of the magnetic particles in the recording layer was improved due to the excellent crystallinity effect.

  The coercive force Hc and the anisotropic magnetic field Hk were measured using VSM. Further, medium noise and S / Nm were measured using a composite magnetic head (recording head: single pole head, write core width 0.5 μm, reproducing head (GMR element): read core width 0.25 μm) having a flying height of 17 nm. The recording density was 400 kFCI.

[Example 3]
As a perpendicular magnetic recording medium according to this example, a perpendicular magnetic recording medium having the following configuration was manufactured. From the substrate side, glass substrate / soft magnetic backing layer: CoNbZr film (190 nm) / magnetic flux slit layer: CoNbZr film (10 nm) / seed layer: Ta film (2 nm) / nonmagnetic intermediate layer: Ru film (15 nm) / recording layer: (Co ₇₁ Cr ₉ Pt ₂₀ ) 90 vol%-(SiO ₂ ) 10 vol% film (10 nm) / protective film: carbon (4 nm) / lubricating layer: AM3001 (1.5 nm). Other than the lubrication layer, an Ar gas atmosphere sputtering device is used, the atmosphere gas pressure of the CoNbZr film and the Ta film of the soft magnetic backing layer is 0.5 Pa, and the atmosphere gas pressure of the CoNbZr film and the Ru film of the magnetic flux slit layer is 4 0.0 Pa.

[Comparative Example 1]
The same procedure as in Example 1 was performed except that the CoNbZr film of the magnetic flux slit layer of Example 3 was set to an atmospheric gas pressure of 0.5 Pa.

  FIG. 5 is a graph showing S / Nm characteristics of the perpendicular magnetic recording media according to Example 3 and Comparative Example 2. Referring to FIG. 5, it can be seen that the S / Nm is larger in Example 3 than in Comparative Example 2 at a recording density of 200 kFCI or higher. For example, at 400 kFCI, Example 3 is 1.7 dB higher than Comparative Example 2. By forming the CoNbZr film of the magnetic flux slit layer at an atmospheric gas pressure of 4.0 Pa, the magnetic isolation from the CoNbZr film formed at 0.5 Pa of Comparative Example 2 is promoted and the magnetic flux from the recording head is increased. It is presumed that the spread is suppressed and the medium noise is reduced. The S / Nm characteristics are the same as the measurement conditions described above.

(Second Embodiment)
A perpendicular magnetic recording medium according to a second embodiment of the present invention, in which nonmagnetic particles and magnetic particles of a nonmagnetic intermediate layer and a recording layer are separated and surrounded by a non-solid solution phase, will be described.

  FIG. 6 is a schematic cross-sectional view of a perpendicular magnetic recording medium according to the second embodiment of the present invention. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 6, the perpendicular magnetic recording medium 40 includes a substrate 11, a soft magnetic backing layer 12, a seed layer 13, an underlayer 31, a nonmagnetic intermediate layer 41, a recording layer 42, and a protective film 18 on the substrate 11. , And the lubricating layer 19 are sequentially laminated.

  The recording layer 42 has a thickness of, for example, 6 nm to 20 nm, a magnetic particle 42a having a columnar structure, and a second non-solid solution made of a nonmagnetic material that surrounds the magnetic particles 42a and physically separates adjacent magnetic particles 42a. It is comprised from the phase 42b. The columnar structure of the magnetic particles 42a extends in the film thickness direction, and is formed so that the second non-solid solution phase 42b is filled between each of a large number of magnetic particles 42a arranged in the in-plane direction.

  The magnetic particles 42a are made of any material selected from the group consisting of Ni, Fe, Co, Ni alloys, Fe alloys, CoCrTa, CoCrPt, and CoCr alloys including CoCrPt-M. Here, M is selected from B, Mo, Nb, Ta, W, Cu, and alloys thereof. The magnetic particle 42a has an easy axis in the film thickness direction. When the ferromagnetic alloy constituting the magnetic particle 42a has an hcp structure, the film thickness direction, that is, the growth direction is preferably the (001) plane.

  When the magnetic particles 42a are made of a CoCrPt alloy, the Co content is set to 50 atomic% to 80 atomic%, the Cr content is set to 5 atomic% to 20 atomic%, and the Pt content is set to 15 atomic% to 30 atomic%. . By containing a larger amount of Pt as compared with the conventional magnetic recording medium, it is possible to increase the perpendicular anisotropy magnetic field and increase the coercive force. In particular, such a high Pt content has been considered to be difficult to epitaxially grow with respect to a Cr-based underlayer, but magnetic particles having excellent crystallinity by using the material of the nonmagnetic particles 42a of the present embodiment. 42a can be formed.

The second non-solid phase 42b is composed of a non-magnetic material that does not form a solid solution or a compound with the ferromagnetic alloy that forms the magnetic particles 42a, and the non-magnetic materials include Si, Al, Ta, Zr, Y, Ti, And a compound of any one element selected from Mg and at least one element selected from O, N, and C. For example, SiO ₂ , Al ₂ O ₃ , Ta ₂ O ₅ , oxides such as ZrO ₂ , Y ₂ O ₃ , TiO ₂ , MgO, nitrides such as Si ₃ N ₄ , AlN, TaN, ZrN, TiN, Mg ₃ N ₂ , SiC, TaC, ZrC, TiC And carbides. Since the magnetic particles 42a are physically separated from the adjacent magnetic particles 42a by the second non-solid phase 42b made of such a nonmagnetic material, the magnetic interaction is reduced, and as a result, the medium noise is reduced. be able to.

  The nonmagnetic material constituting the second non-solid solution phase 42b is preferably an insulating material. It is possible to reduce the interaction between the magnetic particles 42a due to the tunnel effect of the electrons responsible for ferromagnetism.

  The volume concentration of the second non-solid phase 42b is preferably set in the range of 2 vol% to 40 vol% based on the volume of the recording layer 42. If 2 vol% is divided, the magnetic particles 42 a cannot be sufficiently separated from each other, so that the magnetic particles 42 a cannot be sufficiently isolated. If it exceeds 40 vol%, the saturation magnetization of the recording layer 42 is remarkably lowered, and the output during reproduction is increased. descend. Furthermore, the volume concentration of the second non-solid solution phase 42b is particularly preferably set in the range of 8 vol% to 30 vol% from the viewpoint of isolation of the magnetic particles 42a and vertical alignment dispersion.

  The nonmagnetic intermediate layer 41 has a thickness of 3 nm to 40 nm, for example, and includes a crystalline nonmagnetic particle 41a made of a nonmagnetic material, and a first made of a material that surrounds the nonmagnetic particle 41a and does not form a solid solution with the nonmagnetic particle 41a. It is comprised from the non-solid solution phase 41b.

  The nonmagnetic particles 41a are made of at least one nonmagnetic material selected from Co, Cr, Ru, Re, Ti, Hf, and alloys thereof having an hcp structure or an fcc structure. For example, Ru or CoCrRu may be used. Can be mentioned. When the nonmagnetic particle 41a has an hcp structure, the (001) plane is preferably parallel to the in-plane direction. At the interface between the nonmagnetic intermediate layer 41 and the recording layer 42, the magnetic particles 42a can be epitaxially grown on the nonmagnetic particles 41a, and the particle size of the nonmagnetic particles 41a and the gap between adjacent nonmagnetic particles 41a are controlled. Thus, the particle size of the magnetic particles 42a and the gap between the adjacent magnetic particles 42a can be controlled simultaneously.

  Moreover, the 1st non-solid solution phase 41b is comprised from the material similar to the 2nd non-solid solution phase 42b mentioned above. The volume concentration of the first non-solid solution phase 41b is preferably set in the range of 2 vol% to 40 vol% based on the volume of the nonmagnetic intermediate layer 41. Further, the volume concentration of the first non-solid phase 41b is particularly preferably equal to or larger than the volume concentration of the second non-solid phase 42b. The volume concentration of the first non-solid phase 41b: the second non-solid phase 42b It is particularly preferable to have a relationship of volume concentration of 1: 1 to 1.5: 1. Since the magnetic particles 42a tend to grow on the nonmagnetic particles 41a and have a large particle size, is the volume concentration of the first non-solid phase 41b equal to the volume concentration of the second non-solid phase 42b? By increasing the size, the magnetic particles 42a can be isolated.

  It is preferable to control the particle diameter of the nonmagnetic particles 41 a by the underlayer 31 formed below the nonmagnetic intermediate layer 41. The underlayer 31 is made of the material of the underlayer 31 described in the first embodiment. Since the underlayer 31 functions as a growth nucleus of the nonmagnetic particles 41a, the arrangement of the nonmagnetic particles 41a can be controlled, and the crystal orientation and crystallinity can be further improved.

  Among the materials of the underlayer 31, it is preferable that the (111) plane has an fcc structure and is substantially parallel to the substrate surface, and the ratio of lattice mismatch with the nonmagnetic particles 41a is 10% or less. That is, crystallographically, the underlayer 31 is the fcc structure (111) plane // the nonmagnetic intermediate layer 41 is the fcc structure (111) plane or the hcp structure (001), and the lattice mismatch ratio is 10% or less. It is preferable that

  In addition, by forming the underlayer 31 from a soft magnetic material, the underlayer 31 functions as a part of the soft magnetic backing layer 12, so that the spacing from the magnetic head to the surface of the soft magnetic backing layer 12 can be reduced. And electromagnetic conversion characteristics can be improved. Note that the base layer 31 may or may not be provided.

  In the perpendicular magnetic recording medium 40 of the present embodiment, a seed layer is provided below the underlayer 31. The function described in the first embodiment is provided. Note that the base layer 31 may or may not be provided.

  Hereinafter, a method for forming the nonmagnetic intermediate layer 41 and the recording layer 42 will be described.

  The nonmagnetic intermediate layer 41 and the recording layer 42 are formed by sputtering, for example, using a DC magnetron sputtering apparatus, an ECR sputtering apparatus, or the like, and when an insulating material is included, using an RF magnetron sputtering apparatus or the like.

  In the case of forming the nonmagnetic intermediate layer 41, a sputter target made of a nonmagnetic material to be the nonmagnetic particles 41a and a sputter target made of a material to be the first non-solid phase 41b may be sputtered simultaneously. A material obtained by combining the nonmagnetic material to be the first non-solid phase 41b may be used. When the recording layer 42 is formed, as in the case of the nonmagnetic intermediate layer 41, a sputtering target may be used for each of the magnetic material of the magnetic particles 42a and the nonmagnetic material of the second non-solid solution phase 42b. You may use it.

  The atmospheric gas pressure during film formation is preferably set in the range of 2 Pa to 8 Pa. Isolation of the nonmagnetic particles 41a or the magnetic particles 42a can be promoted. The atmosphere gas is preferably Ar gas or Ar gas added with oxygen gas.

  According to the present embodiment, the nonmagnetic intermediate layer 41 provided below the recording layer 42 is formed from the nonmagnetic particles 41a and the first non-solid phase 41b, and the nonmagnetic particles 41a are separated in a self-forming manner. Furthermore, since the magnetic particles 42a of the recording layer 42 grow from the surface of the nonmagnetic particles 41a, the particle size of the magnetic particles 42a and the gap between adjacent magnetic particles 42a can be controlled. Therefore, miniaturization and isolation of the magnetic particles 42a can be realized at the same time.

[Example 4]
The perpendicular magnetic recording medium according to this example was configured as follows. From the substrate side: glass substrate / soft magnetic backing layer: CoNbZr film (120 nm) / seed layer: Ta film (5 nm) / underlayer: NiFe film (5 nm) / nonmagnetic intermediate layer: Ru 86 vol%-(SiO ₂ ) 14 vol% film (20 nm) / recording layer: (Co ₇₆ Cr ₉ Pt ₁₅ ) ₇₆ vol%-(SiO ₂ ) 24 vol% film (10 nm) / protective film: carbon film (4 nm) / lubricating layer: AM3001 (1.5 nm). The CoNbZr film, the Ta film, the NiFe film, and the carbon film were formed by using a DC magnetron sputtering apparatus with an Ar atmosphere gas and a pressure set to 0.5 Pa. The nonmagnetic intermediate layer and the recording layer were made to have an Ar atmosphere gas and a gas pressure of 4.0 Pa using an RF magnetron sputtering apparatus. The substrate temperature during film formation was room temperature. The lubricating layer was applied by a dipping method. In addition, the numerical value in the said parenthesis represents a film thickness.

[Example 5]
Instead of the non-magnetic intermediate layer of Example 4, Ru60vol% - except for forming by using a (SiO ₂₎ 35vol% film (20 nm) were the same as in Example 4.

[Comparative Example 3]
The same procedure as in Example 4 was performed except that a Ru film (20 nm) was used in place of the nonmagnetic intermediate layer of Example 4.

  7A to 7C are schematic diagrams of TEM photographs in plan view of recording layers of perpendicular magnetic recording media according to Examples 4 and 5 and Comparative Example 3, respectively. The curves in the figure represent the contours of the magnetic particles 42a and 42a-1.

  7A to 7C, the recording layer of the perpendicular magnetic recording media according to Example 4 and Example 5 shown in FIGS. 7A and 7B is a comparative example in which the Ru film shown in FIG. 7C is used as the nonmagnetic intermediate layer. It can be seen that the isolation and miniaturization of the magnetic particles 42a are promoted as compared with FIG. The average particle diameter of the magnetic particles was Example 4: 5.6 nm, Example 5: 5.5 nm, and Comparative Example 3: 7.7 nm.

In particular, in Example 5, the gap between adjacent magnetic particles 42a, that is, the distance between the magnetic particles 42a sandwiching the portion of the second insoluble phase 42b made of SiO ₂ is larger than that in Example 4. Moreover, it turns out that the 2nd non-solid solution phase 42b surrounds the magnetic particle 42a uniformly in Example 5 with respect to the non-solid solution phase 42b-1 shown to FIG. 7C.
By setting the volume concentration of the first non-solid phase of the nonmagnetic intermediate layer from 14 vol% to 35 vol%, the volume concentration of the second non-solid phase of the magnetic layer is higher than 24 vol% which is the volume concentration of the magnetic particles in the recording layer. It can be seen that the gap of the increases.

  FIG. 8 is a diagram showing the characteristics of the perpendicular magnetic recording media according to Examples 4 and 5. In FIG. Referring to FIG. 8, Example 5 is closer to 1 than α in Example 4 for α. As shown above, α indicates that magnetic isolation of magnetic particles is advanced as the value is closer to 1, and it can be seen that the magnetic isolation of Example 5 is more advanced than that of Example 4. In addition, it turns out that it corresponds with the physical isolation of the plane TEM photograph mentioned above.

  As for S / Nm, Example 4 is significantly improved to 11 dB compared to 11 dB in Example 5. When combined with the result of α, it can be seen that the isolation of the magnetic particles is promoted, thereby reducing the medium noise and improving the S / Nm.

  Similarly, D50 is larger in Example 5 than in Example 4. This shows that higher density recording is possible.

Therefore, according to the present embodiment, the nonmagnetic intermediate layer is made of a Ru— (SiO ₂ ) film, so that the magnetic particles can be isolated and miniaturized as compared with the Ru film. Further, the gap between the magnetic particles can be controlled by the volume concentration of the first non-solid phase of the nonmagnetic intermediate layer, and the magnetic particles can be magnetically isolated. Furthermore, by making the volume concentration of the first non-solid phase of the nonmagnetic intermediate layer higher than the volume concentration of the second non-solid phase of the recording layer, the magnetic particles can be further isolated and the S / Nm And D50 can be improved.

  Although not shown, the cross-sectional TEM observation of the perpendicular magnetic recording media of Examples 4 and 5 shows that the nonmagnetic intermediate layer 41 and the recording layer 42 have a columnar structure in which nonmagnetic particles and magnetic particles extend in the film thickness direction. I confirmed.

  The average particle diameter is measured by extracting the outline of a magnetic particle from a planar TEM photograph (2 million times on the photograph) and taking it into a PC with a scanner to determine the area of the magnetic particle. The diameter of the magnetic particles was used as the particle size of the magnetic particles, 150 magnetic particles were randomly selected, and the average value of the particle sizes was determined as the average particle size.

  The perpendicular coercivity, saturation magnetization, and α were measured under the same conditions as in Examples 1 and 2 according to the first embodiment. S / Nm and D50 were measured using a composite magnetic head (recording head: single pole head, write core width 0.5 μm, reproducing head (GMR element): read core width 0.25 μm) having a flying height of 17 nm. .

(Third embodiment)
A perpendicular magnetic recording medium according to a third embodiment of the present invention in which a soft magnetic shielding layer is provided on the recording layer will be described.

  FIG. 9 is a schematic sectional view of a perpendicular magnetic recording medium according to the third embodiment of the present invention. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 9, the perpendicular magnetic recording medium 50 includes a substrate 11, a soft magnetic backing layer 12, a seed layer 13, an underlayer 31, a nonmagnetic intermediate layer 15, a recording layer 16, and a soft magnetic shield on the substrate 11. The layer 51, the protective film 18, and the lubricating layer 19 are sequentially stacked.

The soft magnetic shielding layer 51 is formed on the recording layer 16 described in the first or second embodiment, and is made of a high magnetic permeability soft magnetic material having a thickness of 2 to 50 nm, for example. The soft magnetic material used for the soft magnetic shielding layer 51 includes at least one element selected from Fe, Co, Ni, Al, Si, Ta, Ti, Zr, Hf, V, Nb, C, and B. It is composed of an amorphous or microcrystalline alloy, or a laminated film of these alloys. For example, Ni ₈₀ Fe ₂₀ , Ni ₅₀ Fe ₅₀ , FeSi, FeAlSi, FeTaC, CoNbZr, CoCrNb, CoTaZr, NiFeNb, and the like can be used.

  The soft magnetic shielding layer 51 preferably has an easy axis direction of magnetization in an in-plane direction. Further, it is particularly preferable that the easy axis direction is perpendicular to the longitudinal direction of the track, that is, perpendicular to the recording direction. It is possible to suppress the occurrence of a domain wall that becomes a noise source in the soft magnetic shielding layer 51 as much as possible. For example, if the perpendicular magnetic recording medium 50 is a magnetic disk, the easy axis is set in the radial direction, and if it is a lateral magnetic tape, the easy axis is set in the width direction of the magnetic tape.

  The soft magnetic shielding layer 51 is preferably a soft magnetic material having a magnetic permeability in the range of 20 to 2000. The followability to a high-frequency recording magnetic field is improved.

  The soft magnetic shielding layer 51 preferably has a saturation magnetization in the range of 0.1T to 2.4T. If it exceeds 2.4T, the range of selection of the magnetic pole material of the recording head is limited.

Further, the soft magnetic shielding layer 51 has a saturation magnetic flux density Bs _S of the soft magnetic shielding layer 51 where the saturation magnetic flux density of the magnetic material of the main magnetic pole of the recording head is Bs _H and the thickness of the tip of the main magnetic pole is t _H. The film thickness t _S is preferably set to Bs _S × t _S <Bs _H × t _H. The soft magnetic shielding layer 51 can be reliably magnetically saturated by the magnetic field from the main pole.

In the perpendicular magnetic recording medium 50 of the present embodiment, since the soft magnetic shielding layer 51 is provided on the recording layer 16, when the recording magnetic field is smaller than a predetermined amount, the recording magnetic field is soft magnetic shielding layer 51. The recording layer cannot be reached. By making the recording magnetic field equal to or greater than the magnitude of the magnetic field that causes the soft magnetic shielding layer 51 to be magnetically saturated, the recording magnetic field can pass through the soft magnetic shielding layer 51 and magnetize the recording layer.

  FIG. 10 is a diagram showing a recording state of the perpendicular magnetic recording medium according to the present embodiment. For convenience of explanation, the protective film 18 and the lubricating layer 19 are not shown in FIGS.

  Referring to FIG. 10, at the time of recording, a recording magnetic field Hw is applied to the perpendicular magnetic recording medium 50 from the tip of the main magnetic pole 55 of the recording head facing the perpendicular magnetic recording medium 50 of the magnetic storage device. When a recording magnetic field is applied, when the recording magnetic field is equal to or less than the magnetic field that causes the soft magnetic shielding layer 51 to be magnetically saturated, the magnetic flux from the recording head is sucked by the soft magnetic shielding layer 51 and does not reach the recording layer 16. When the recording magnetic field further increases, the region 51a of the soft magnetic shielding layer 51 facing the substantially central portion of the tip of the main pole is magnetically saturated. When magnetic saturation occurs, the recording magnetic field passes through the soft magnetic shielding layer 51 and reaches the recording layer 16, and further reaches the soft magnetic backing layer 12. In this way, a recording magnetic field is applied to the recording layer 16a, and magnetization Ma is generated. Here, the magnetic field Hwb leaking from the peripheral portion of the front end portion of the main magnetic pole 55 is weaker than the central portion, and such a magnetic field Hwb is absorbed into the soft magnetic shielding layer 51. Since the magnetic field Hwa leaked from the central portion magnetically saturates the soft magnetic shielding layer 51, the size of the region 16a in which the soft magnetic shielding layer 51 is saturated should be smaller than the size of the main magnetic pole tip 55. Can do.

FIG. 11 is a plan view of FIG. Referring to FIG. 11, the region where the soft magnetic shielding layer 51 is saturated is formed almost immediately below the tip of the main magnetic pole 55. A bit surrounded by the magnetization transition region 16a corresponding to the recording signal is formed along the direction in which the perpendicular magnetic recording medium 50 moves (direction Mv indicated by an arrow). On the other hand, the track width direction can be soft-magnetic shielding layer 51 to form a track Tk _n of approximately the same width as the width of the area to be saturated. In other words, it is possible to solve problems that erases the magnetization of adjacent tracks _{Tk n-1, Tk n +} 1 by controlling the width of the saturation region 51a to the same extent as the track Tk _n width, i.e. the side track erasing . For example, the width of the saturated region 51a can be controlled by the recording current value, the magnetic permeability or film thickness of the soft magnetic shielding layer 51, and the like.

FIG. 12 is a diagram showing a state of reproduction from the perpendicular magnetic recording medium according to the present embodiment. Referring to FIG. 12, the reproducing head 56 uses an MR element sandwiched by a shield along the moving direction of the perpendicular magnetic recording medium 50. When the reproducing head 56 is brought close to the perpendicular magnetic recording medium 50, a magnetic field is generated in the shield 58a-soft magnetic shielding layer 51-shield 58b due to the influence of the sense current flowing in the MR element and the magnetization of the soft magnetic shielding layer 51, and the shields 58a, 58b. Can be magnetically saturated with the soft magnetic shielding layer 51 opposed to the region 51 and the region 51c therebetween. The soft magnetic shielding layer 51 has an easy axis of magnetization in the in-plane direction, and the direction of the magnetic field in the soft magnetic shielding layer 51 is in the in-plane direction. Therefore, the soft magnetic shielding layer 51 can be magnetically saturated with a weak magnetic field. For example, a soft magnetic material of Ni ₅₀ Fe ₅₀ can be magnetically saturated with a magnetic field of about 240 A / m. As a result, the magnetic field leaking from the magnetization Ma of the lower recording layer 16 is transmitted through the saturation region 51 c of the soft magnetic shielding layer 51 and reaches the MR element 59 of the reproducing head 56. Therefore, the magnetization state of the recording layer 16 can be reproduced.

FIG. 13 is a plan view of FIG. Referring to FIG. 13, the saturation region 51 c of the soft magnetic shielding layer 51 is the soft magnetic shielding layer 51 facing the shields 58 a and 58 b and the region therebetween, and the MR element 59 is surrounded by the magnetization transition region 16 a of the recording layer 16. The magnetic field leaking from the magnetized magnetization can be reproduced. By making the width of the saturation region 51c equal to the track width, crosstalk from the adjacent tracks Tkn _-1 and Tkn _{+ 1} can be reduced. Further, the width of the MR element 59 may be made smaller than the width of the saturation region 51c.

  Hereinafter, a method for manufacturing the perpendicular magnetic recording medium 50 according to the present embodiment will be described. The perpendicular magnetic recording medium 50 is formed from the soft magnetic backing layer 12 to the recording layer 16 from the substrate 11 side shown in FIG. 9 in the same manner as described in the first embodiment or the second embodiment. To do.

  The soft magnetic shielding layer 51 is formed by sputtering, for example, using a DC magnetron apparatus. The following two methods can be used as a method for orienting the easy axis of magnetization in the direction perpendicular to the direction of movement of the perpendicular magnetic recording medium 50 during recording.

  FIG. 14 is a diagram schematically showing a film forming apparatus for applying a magnetic field to orient the easy axis of magnetization. Referring to FIG. 14, a magnetic pole 60N is arranged at the center of the perpendicular magnetic recording medium 50, a magnetic pole 60S is arranged at the outer periphery, a DC magnetic field Hap is applied in the radial direction, and the perpendicular magnetic recording medium 50 is softened while rotating in the Rt direction, for example. The sputtered particles IB of the magnetic shielding layer 51 are made incident. Here, the DC magnetic field is set to about 80 kA / m. In the figure, a direct-current magnetic field is shown to be applied to a part of the perpendicular magnetic recording medium 50. However, an outer peripheral magnetic pole 60S is arranged on the entire outer periphery so as to be applied to the entire perpendicular magnetic recording medium 50. Also good.

  FIG. 15 is a diagram schematically showing a film forming apparatus for injecting sputtered particles obliquely to orient the easy magnetization axis. Referring to FIG. 15, sputtered particles IB of the soft magnetic shielding layer 51 are made incident while the perpendicular magnetic recording medium 50 is rotated in the Rt direction, for example. The incident direction is inclined toward the outer circumferential direction of the perpendicular magnetic recording medium 50 by an incident angle θin with respect to a surface formed by the circumferential direction θr and a direction perpendicular to the surface of the perpendicular magnetic recording medium 50 (Z direction). The incident angle θin is preferably set to be greater than 0 degree and 60 degrees or less. Next, the protective film 18 and the lubricating layer 19 are formed in the same manner as in the first embodiment.

  As described above, the magnetic recording medium 50 in which the easy magnetization axis of the soft magnetic shielding layer 51 is oriented in the direction perpendicular to the moving direction at the time of recording can be formed.

  According to the present embodiment, a saturation region is formed by a recording magnetic field in a part of the soft magnetic shielding layer 51 provided on the recording layer 16 and a recording magnetic field is passed therethrough, whereby the recording layer 16 below the saturation region is passed. Only can be magnetized. Therefore, the spread of magnetic flux from the recording head can be suppressed, and adjacent track erase can be prevented. Further, since the magnetic flux from the recording head is concentrated, the recording magnetic field is increased, and the writing performance of the recording layer can be improved.

  FIG. 16 is a schematic cross-sectional view of a perpendicular magnetic recording medium according to a modification of the present embodiment. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 16, the perpendicular magnetic recording medium 55 includes a substrate 11, a soft magnetic backing layer 12, a seed layer 13, an underlayer 31, a nonmagnetic intermediate layer 15, a recording layer 16, and a nonmagnetic layer on the substrate 11. 52, a soft magnetic shielding layer 51, a protective film 18, and a lubricating layer 19 are sequentially laminated, except that a nonmagnetic layer 52 is provided between the recording layer 16 and the soft magnetic shielding layer 51. This is the same as the perpendicular magnetic recording medium of the third embodiment.

The nonmagnetic layer 52 is formed by sputtering or the like, has a thickness set in the range of 0.5 nm to 20 nm, and is made of a nonmagnetic material. Non-magnetic material is not particularly limited, for example, can be used _{SiO 2, Al 2 O 3,} TiO 2, TiC, C, a hydrogenated carbon.

  According to the present embodiment, by providing the nonmagnetic layer between the recording layer 16 and the soft magnetic shielding layer 51, it is possible to prevent the recording layer 16 and the soft magnetic shielding layer 51 from being magnetically coupled. it can.

  Examples of the present embodiment will be described below.

[Example 6]
The perpendicular magnetic recording medium according to this example was configured as follows. From the substrate side, glass substrate / soft magnetic backing layer: CoNbZr film (200 nm) / seed layer: Ta film (5 nm) / underlayer: NiFe film (5 nm) / nonmagnetic intermediate layer: Ru film (20 nm) / recording layer: ( Co ₈₆ Cr ₈ Pt ₆ ) 90 vol%-(SiO ₂ ) 10 vol% film (10 nm) / nonmagnetic layer: Ta film (4 nm) / soft magnetic shielding layer: Ni ₈₀ Fe ₂₀ film (X nm, saturation magnetic flux density 1.1 T ) / Protective film: Carbon film (10-X nm) / Lubricating layer: AM3001 (1.5 nm). Samples were prepared in which the film thickness X of the NiFe film of the soft magnetic shielding layer was varied from 0 to 10 nm. Further, in order to make the distance from the recording head to the surface of the recording layer constant, the thickness of the protective film was set to 10-X nm with respect to the thickness Xnm of the NiFe film. The CoNbZr film, the nonmagnetic layer Ta film, the soft magnetic shielding layer NiFe film, and the carbon film are formed using an Ar gas atmosphere sputtering apparatus. Was set to 0.5 Pa. The Ta film of the seed layer, the NiFe film of the underlayer, and the Ru film were made to have an Ar atmosphere gas and a gas pressure of 4.0 Pa using a DC magnetron sputtering apparatus. The recording layer was made to have an Ar atmosphere gas and a gas pressure of 4.0 Pa using an RF magnetron sputtering apparatus. The substrate temperature during film formation was room temperature. The lubricating layer was applied by a dipping method. In addition, the numerical value in the said parenthesis represents a film thickness.

  FIG. 17 is a diagram showing the relationship between S / Nm and the thickness of the soft magnetic shielding layer in Example 6. Referring to FIG. 17, it can be seen that the S / Nm is higher when the soft magnetic shielding layer is not provided (film thickness = 0). Further, by increasing the thickness of the soft magnetic shielding layer, the S / Nm increases and the film thickness becomes maximum at 8 nm. From this, as the film thickness increases, the amount of magnetic flux that sucks in the magnetic flux from the recording head increases, the amount of magnetic flux that seeps into the recording layer decreases, the area of the saturation region decreases, and becomes narrower The magnetic flux constricted only in the saturation region passes and the recording layer is magnetized. As a result, it is assumed that the recording layer in a narrow range equivalent to the main pole is magnetized by a high recording magnetic field.

  S / Nm is a composite magnetic head having a flying height of 8 nm (recording head: single pole head, write core width 0.2 μm, saturation magnetic flux density × write core thickness 0.4 μTm, recording current 5 mA, reproducing head (GMR Element): measured using a lead core width of 0.12 μm, and the recording density was 500 kFCI. Note that the measurement conditions in FIGS.

  FIG. 18 is a diagram showing the relationship between the reproduction output reduction rate and the soft magnetic shielding layer thickness in Example 6 in the adjacent track erase test. Referring to FIG. 18, it can be seen that when the soft magnetic shielding layer is not provided (thickness = 0), the reduction rate of the reproduction output of the adjacent track is small. It can also be seen that the decrease rate of the reproduction output of the adjacent track monotonously decreases as the thickness of the soft magnetic shielding layer is increased. This shows that the soft magnetic shielding layer suppresses the magnetic flux leaking in the track width direction.

In the adjacent track erase test, after recording at a recording density of 100 kFCI on the measurement track and measuring the initial reproduction output V ₀ , the recording head is turned off by 0.25 μm and the DC erase operation is repeated 100 times. a is on-track to measure the reproduction output _{V 1} of the measurement track, and the reproduction output decrease rate _{(%) = (V 1 -V} 0) / V 0 × 100%.

  FIG. 19 is a diagram illustrating the relationship between S / Nm and recording current in Example 6. In FIG. 17, a sample having a S / Nm maximum value and a soft magnetic shielding layer thickness of 8 nm was used.

  Referring to FIG. 19, it can be seen that S / Nm shows the maximum value with respect to the recording current. From this, it can be seen that when a moderately saturated region is formed in the soft magnetic shielding layer, the magnetic flux from the recording head concentrates and sufficient writing can be performed.

[Example 7]
The perpendicular magnetic recording medium according to this example was configured as follows. From the substrate side, glass substrate / soft magnetic backing layer: CoTaZr film (200 nm) / nonmagnetic intermediate layer: Ru film (20 nm) / recording layer: (Co ₇₉ Cr ₈ Pt ₁₃ ) 90 vol%-(SiO ₂ ) 10 vol% film ( 10 nm) / non-magnetic layer: Ta film (X nm) / soft magnetic shielding layer: Ni ₅₀ Fe ₅₀ film (20 nm, saturation magnetic flux density 1.3 T) / protective film: carbon film (4 nm) / lubricating layer: AM3001 (1. 5 nm). Samples were prepared in which the thickness X of the nonmagnetic Ta film was varied from 2 to 10 nm. The film forming conditions were the same as in Example 6.

  FIG. 20 is a graph showing the relationship between S / Nm and the nonmagnetic layer thickness in Example 7. Referring to FIG. 20, S / Nm is the highest at 9.6 dB when the nonmagnetic layer thickness is 2 nm. It can be seen that the improvement is 1.4 dB as compared with the case where the nonmagnetic layer is not provided (film thickness = 0). Also, S / Nm monotonously decreases as the nonmagnetic layer thickness increases. Therefore, by providing the nonmagnetic layer, it is possible to improve the S / Nm by preventing the recording layer and the soft magnetic shielding layer from being magnetically coupled.

(Fourth embodiment)
A perpendicular magnetic recording medium according to a fourth embodiment of the present invention in which a magnetic flux slit layer in which semi-hard or soft magnetic particles are arranged in a nonmagnetic matrix or the like is provided on a recording layer will be described.

  FIG. 21 is a schematic sectional view of a perpendicular magnetic recording medium according to the fourth embodiment of the present invention. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 21, a perpendicular magnetic recording medium 50 includes a substrate 11, a soft magnetic backing layer 12, a seed layer 13, an underlayer 31, a nonmagnetic intermediate layer 15, a recording layer 16, and a magnetic flux slit layer on the substrate 11. 71, the protective film 18, and the lubricating layer 19 are sequentially laminated.

  The magnetic flux slit layer 71 is formed on the recording layer 16 described in the first or second embodiment, has a thickness of 2 nm to 20 nm, and a semi-hard or soft magnetic magnetic particle is made of a nonmagnetic material. It is formed so as to be surrounded by a magnetic matrix or nonmagnetic grain boundaries, and has an easy magnetization axis in the film thickness direction. Since the magnetic fine particles are separated by a nonmagnetic matrix or nonmagnetic particles in the in-plane direction, they are magnetically isolated and have an easy magnetization axis in the film thickness direction. It is sucked into semi-hard or soft magnetic magnetic particles having a magnetic permeability higher than that of the magnetic matrix or non-magnetic particles, and particularly sucked into the magnetic particles closest to the recording head. The sucked magnetic flux passes through the recording layer 16 in contact with the magnetic flux slit layer 71 and reaches the soft magnetic backing layer 12. Therefore, it has an effect that the recording head substantially contacts the recording layer 16, and has an effect of increasing the recording magnetic field and steepening the spatial distribution of the recording magnetic field.

  Specifically, the magnetic flux slit layer 71 is composed of a semi-hard ferrite film, a granular film containing semi-hard ferrite particles or soft magnetic fine particles, or a soft magnetic nanocrystal film.

The semi-hard ferrite film is preferably γ-iron oxide (γ-Fe ₂ O ₃ ), magnetite (Fe ₃ O ₄ ), hexagonal plate-shaped barium ferrite (BaFe ₁₂ O ₁₉ ) or the like having a needle-like structure. Using these materials as a sputtering target, the substrate is heated by sputtering, and after formation, magnetic anisotropy is imparted in the film thickness direction by heat treatment in a magnetic field.

In addition, the granular film containing semi-hard ferrite particles or soft magnetic particles can use the above-described particles such as γ-Fe ₂ O ₃ , Fe ₃ O ₄ , BaFe ₁₂ O _19, etc. as the semi-hard ferrite particles. As the magnetic particles, a material containing at least one element selected from Co, Fe, and Ni can be used. The nonmagnetic matrix is composed of at least one material selected from SiO ₂ , Al ₂ O ₃ , C, and Fe ₃ O ₄ . For example, γ-Fe ₂ O ₃ particles and Fe ₃ O ₄ particles have a needle-like shape with a longitudinal length of about 10 nm and a longitudinal coercive force of 15.8 kA / m (200 Oe) to 35. .6 kA / m (450 Oe), saturation magnetization is 70 emu / g to 80 emu / g. The BaFe ₁₂ O ₁₉ particles have a hexagonal size of about several tens of nm, a thickness of about 10 nm, and a coercive force in the thickness direction of 15.8 kA / m (200 Oe) to 47.4 kA /. m (600 Oe), saturation magnetization is 50 emu / g to 58 emu / g.

The soft magnetic nanocrystal film is formed of, for example, a FeMB (M = Zr, Hf, Nb) film, a FeMO (M = Zr, Hf, Nb, Y, Ce) film, and the like, and magnetic particles containing a large amount of α-Fe; It is composed of a nonmagnetic and amorphous grain boundary containing a large amount of M and B or O. The magnetic particles have a particle size in the in-plane direction of about 10 nm to 100 nm, and the grain boundary portion physically separates the magnetic particles from adjacent magnetic particles. For example, J. et al. Appl. Phys. vol. 81 (1997) p2736, in FeMB, the magnetic permeability is improved by adding about 1 atomic% of Cu (for example, Fe ₈₄ Nb _3.5 Zr _3.5 B ₈ Cu ₁ ) and optimizing chemical synthesis. It is also effective in making crystals finer.

  As the soft magnetic nanocrystal film, an FeZrB film having a thickness of, for example, 8 nm is formed on the recording layer 16 by sputtering or the like. By performing heat treatment at a low temperature before the crystallization treatment, the sizes of the crystal grains can be made uniform and the magnetic permeability can be improved.

  According to the present embodiment, since the magnetic flux slit layer 71 in which the magnetic particles surrounded by the nonmagnetic matrix or the nonmagnetic grain boundary are disposed is provided on the recording layer 16, the magnetic flux slit layer from the recording head is provided. The magnetic flux flowing through the soft magnetic backing layer 12 via the recording layer 16 and the recording layer 16 is narrowed so as to pass through the magnetic particles in the magnetic flux slit layer 71, and the spread of the magnetic flux from the recording head to the recording layer 16 is suppressed to generate the magnetic flux. You can concentrate. Therefore, erasure of adjacent tracks due to the spread of magnetic flux can be prevented, and the track density can be improved. Also, the width of the magnetization transition region can be narrowed in the longitudinal direction of the track, and the linear recording density can be improved. As a result, a perpendicular magnetic recording medium with a high recording density can be realized.

(Fifth embodiment)
A perpendicular magnetic recording medium according to the fifth embodiment of the present invention, in which a magnetic flux slit layer in which nonmagnetic particles are arranged in a ferromagnetic matrix, is provided on the recording layer will be described.

  FIG. 22 is a schematic cross-sectional view of a perpendicular magnetic recording medium according to the fifth embodiment of the invention. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 22, the perpendicular magnetic recording medium 75 includes a substrate 11, a soft magnetic backing layer 12, a seed layer 13, an underlayer 31, a nonmagnetic intermediate layer 15, a recording layer 16, and a magnetic flux slit layer on the substrate 11. 76, the protective film 18 and the lubricating layer 19 are sequentially laminated.

The magnetic flux slit layer 76 has a thickness of 2 nm to 10 nm, and is configured by disposing nonmagnetic fine particles 76b in a ferromagnetic matrix phase 76a made of an alloy of a rare earth metal and a transition metal. The rare earth metal of the ferromagnetic matrix 19 is selected from Tb, Gd, and Dy, and may include one or more. The transition metal is selected from Fe and Co, and may include one or two kinds. Examples of the ferromagnetic mother phase 76a include TbFeCo, GdFeCo, DyFeCo, and the like. In the case of an alloy of rare earth and FeCo (Tb, Gd, Dy, or an alloy thereof) _x (Fe _100-y Co _y ) _{100- When} expressed as _x , it is preferable to set x = 10 atomic% to 30 atomic% and y = 40 atomic% or less. In such a range, the easy axis of magnetization of the ferromagnetic matrix is in the film thickness direction, so that the magnetic flux can be passed according to the increase or decrease of the magnetic flux from the recording head. As a result, magnetic saturation of the ferromagnetic matrix can be avoided and the magnetic flux can be confined.

  The nonmagnetic fine particles 76b include any one element selected from the group consisting of Si, Al, Ta, Zr, Y, and Mg, and at least one element selected from the group consisting of O, C, and N. Selected from the following compounds: Specifically, the material is selected from substantially the same material as the second non-solid solution phase 42b of the second embodiment. Since these oxides, nitrides, carbides and the like form a covalent bond compound, they are easily separated from the rare earth metal-transition metal alloy material constituting the ferromagnetic matrix layer 76a, and the fine particles in the ferromagnetic matrix phase 76a. To be deposited. That is, the nonmagnetic fine particles 76 b are formed in the ferromagnetic matrix 19 in a self-forming manner.

  The nonmagnetic fine particles 76b preferably contain Y (yttrium). When the nonmagnetic fine particle 76b contains oxygen, it inhibits the formation of a selective bond (for example, Tb-O) between the rare earth metal and oxygen in the ferromagnetic matrix 76a, and the saturation magnetic flux density of the ferromagnetic matrix 76a. Can be prevented.

  The average particle diameter of the nonmagnetic fine particles 76b is preferably set in the range of 3 nm to 10 nm, and the average gap between the nonmagnetic fine particles and the adjacent nonmagnetic fine particles is preferably set in the range of 0.5 nm to 10 nm. By setting such a range, the magnetic flux can be sufficiently narrowed with respect to the size of the recorded bit.

The magnetic flux slit layer 76 is formed by a vacuum deposition method, a sputtering method, or the like. For example, when the sputtering method is used, the magnetic flux slit layer 76 is formed by simultaneously sputtering using, for example, a TbFeCo sputtering target and a YSiO ₂ sputtering target. As an example of the present embodiment, a sputtering target of TbFeCo (20 atomic% Tb-72 atomic% Fe-8 atomic% Co) and YSiO ₂ is simultaneously sputtered on the recording layer using an RF magnetron sputtering apparatus. Based on the volume of the magnetic flux slit layer 76, 70% by volume of YSiO2 and a magnetic flux slit layer 76 of 10 nm thickness were formed. As the sputtering target, a composite type sputtering target in which TbFeCo and YSiO2 are mixed may be used in addition to the above two sputtering targets.

  According to the present embodiment, since the magnetic flux slit layer 76 in which the nonmagnetic fine particles 76b are arranged in the ferromagnetic matrix phase 76a is provided on the recording layer 16, the magnetic flux slit layer 76 and the recording layer are formed from the recording head. The magnetic flux flowing through the soft magnetic underlayer 12 through the magnetic flux 16 is narrowed so as to pass through the ferromagnetic matrix 76 a between the nonmagnetic particles 76 b in the magnetic flux slit layer 76, and the magnetic flux spreads from the recording head to the recording layer 16. Can be suppressed and the magnetic flux can be concentrated. Therefore, erasure of adjacent tracks due to the spread of magnetic flux can be prevented, and the track density can be improved. Also, the width of the magnetization transition region can be narrowed in the longitudinal direction of the track, and the linear recording density can be improved. As a result, a perpendicular magnetic recording medium with a high recording density can be realized.

  FIG. 23 is a schematic cross-sectional view of a perpendicular magnetic recording medium according to a modification of the fifth embodiment.

  A perpendicular magnetic recording medium 80 according to this modification includes a substrate 11, a soft magnetic backing layer 12, a seed layer 13, an underlayer 31, a nonmagnetic intermediate layer 15, a recording layer 16, a magnetic flux slit layer 81 on the substrate 11. A protective film 18 and a lubricating layer 19 are sequentially laminated. Instead of the magnetic flux slit layer 76 shown in FIG. 22, a crystal growth nucleus 81b made of a nonmagnetic material formed on the surface of the recording layer 16, and The perpendicular magnetic recording medium according to the fifth embodiment except that a magnetic flux slit layer 81 composed of a soft magnetic base layer 81a made of a soft magnetic material filled in a gap between adjacent crystal growth nuclei 81b is provided. It is the same.

  The crystal growth nuclei 81b of the magnetic flux slit layer 81 are formed on the surface of the recording layer 16 by sputtering, vacuum deposition, CVD, or the like by using Al, Ta, Ti, Ag, Cu, Pb, Si, B, Zr, Cr, Ru. , Re, and alloys thereof are selected from nonmagnetic materials. The crystal growth nuclei 81b are crystal growth nuclei formed at the initial stage of the film formation process, and the size of the crystal growth nuclei 81b and the size of the gap between the adjacent crystal growth nuclei 81b are the substrate temperature, the deposition amount, It can be controlled by the deposition rate.

  The soft magnetic mother layer 81a is filled with a soft magnetic material having a high saturation magnetic flux density, for example, substantially the same material as the soft magnetic backing layer 12. The soft magnetic mother layer 81a is preferably thinner than the crystal growth nucleus 81b. It is possible to effectively constrict by preventing the spread of magnetic flux.

  According to this modification, since the crystal growth nuclei 81b made of a non-magnetic material are spaced apart from the soft magnetic mother layer 81a between the recording layer 16 and the protective film 18, the recording head 16 The magnetic flux is constricted by the soft magnetic material filled between the crystal growth nuclei 81 b, the spread of the magnetic flux can be suppressed, and the magnetic flux can be concentrated on the recording layer 16. A nonmagnetic layer having a thickness of 1.0 to 5.0 nm may be provided between the magnetic flux slit layers 76 and 81 and the recording layer 16. The magnetic interaction between the magnetic flux slit layers 76 and 81 and the recording layer 16 can be cut off.

(Sixth embodiment)
A perpendicular magnetic recording medium according to the sixth embodiment of the present invention in which a tip-like magnetic body made of a soft magnetic material is disposed in the in-plane direction between the soft magnetic backing layer and the recording layer will be described.

  FIG. 24 is a schematic sectional view of a perpendicular magnetic recording medium according to the sixth embodiment of the present invention. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 24, a perpendicular magnetic recording medium 90 according to the present embodiment includes a substrate 11, a soft magnetic backing layer 12, a nonmagnetic intermediate layer 15, a tip-shaped magnetic body 91, and a recording layer 16 on the substrate 11. The protective film 18 and the lubricating layer 19 are sequentially laminated.

  The tip-like magnetic body 91 is made of, for example, a semi-hard material or a soft magnetic material having a coercive force of 79 kA / m or less formed by sputtering, and has an easy axis in the film thickness direction. As a method for orienting the easy magnetization axis in the film thickness direction, a material in which the easy magnetization axis is oriented in the film thickness direction, for example, 19 atomic% to 28 atomic% Gd—Fe film, 20 atomic% to 30 atomic% Nd—Fe is used. Examples thereof include a film and a 20 atomic% to 30 atomic% Nd—Co film. The easy axis of magnetization can be oriented in the film thickness direction by using a sputtering method, for example, a DC magnetron sputtering method. Further, a Ru film or a Pd film may be used for the nonmagnetic intermediate layer 15 and the tip-like magnetic body 91 may be a CoCr film.

  The tip-shaped magnetic body 91 has a size of, for example, 0.6 nm to 20 nm × 0.6 nm to 20 nm, a thickness of 2 nm to 10 nm, and an interval between adjacent tip-shaped magnetic bodies 91 of 0.6 nm to 20 nm. The magnetic intermediate layer 15 is disposed substantially uniformly on the surface. The tip-like magnetic body 91 is preferably set to a size and interval at which at least two tip-like magnetic bodies 91 are arranged with respect to the size of the recording bit formed in the recording layer 16. Magnetic flux from the recording head can be concentrated on the recording layer 16.

  FIG. 25 is a plan view of a perpendicular magnetic recording medium 90 according to the sixth embodiment. Referring to FIG. 25, the pattern 18a of the tip-like magnetic body 91 appears on the surface of the perpendicular magnetic recording medium 90, and functions as a so-called texture. When a magnetic head (not shown) stops on the surface of the perpendicular magnetic recording medium 90, the magnetic head can be prevented from being attracted.

  Next, a method for forming the tip-like magnetic body 91 will be described below.

  First, a soft magnetic layer to be the tip-shaped magnetic body 91 is formed on the nonmagnetic intermediate layer 15 by sputtering, vapor deposition, or the like. Next, an electron beam resist film is applied using a spin coater, and after baking, the texture shape pattern drawn on a stencil mask with a reduction ratio of 4 is transferred by an electron beam batch projection exposure method.

  Next, post-exposure baking is performed, and development is performed to form a resist pattern. Using this resist pattern as a mask, the soft magnetic layer is etched by ion milling until the nonmagnetic intermediate layer is reached. Next, the resist pattern is removed.

  By such a process, since the address unit of the current mask data is 2.5 nm and patterning is performed at a reduction ratio of 4 times, the tip-shaped magnetic body 91 having a minimum size of about 0.6 nm can be formed. .

  The magnetic flux slit layer 91 may be a rectangular pattern 18b shown in FIG. 26 instead of the circular pattern obtained in a plan view shown in FIG. The pattern 18b is formed such that the sides of the pattern 18b intersect perpendicularly with respect to the moving direction Mv of the perpendicular magnetic recording medium 90 indicated by an arrow. By controlling the shape and height of the tip-shaped magnetic body 91 with respect to the moving direction Mv, the possibility that the magnetic head contacts the surface of the perpendicular magnetic recording medium 90 and crashes can be reduced.

  Further, a nonmagnetic layer may be provided between the tip-shaped magnetic body 91 and the recording layer 16. The magnetic coupling between the tip-shaped magnetic body 91 and the recording layer 16 can be cut. The unevenness formed by the tip-like magnetic body 91 may be adjusted by covering the tip-like magnetic body 91 with a nonmagnetic layer and grinding it by an etching method or a chemical mechanical polishing method. The texture effect can be controlled by reducing the surface roughness of the perpendicular magnetic recording medium 90.

  According to the present embodiment, the tip-like magnetic body 91 is provided between the soft magnetic backing layer 12 and the recording layer 16, and the tip-like magnetic body 91 has an easy magnetization axis in the film thickness direction. Can be concentrated by the tip-shaped magnetic body 91, the magnetic flux can be concentrated on the recording layer 16, and the magnetic field gradient can be made steep. Further, since the shape of the tip-like magnetic body 91 is transferred in the film thickness direction, an uneven texture pattern is formed on the surface of the perpendicular magnetic recording medium 90 to prevent the magnetic head from adsorbing to the surface. The possibility that a crash will occur can be reduced.

(Seventh embodiment)
A perpendicular magnetic recording medium according to the seventh embodiment of the present invention in which a magnetic flux control layer made of a superconducting material is provided between the soft magnetic backing layer and the recording layer will be described.

  FIG. 27 is a schematic sectional view of a perpendicular magnetic recording medium according to the seventh embodiment of the present invention. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 27, the perpendicular magnetic recording medium 100 has a substrate 11 and a soft magnetic backing layer 12, a magnetic flux control layer 101, a recording layer 16, a protective film 18, and a lubricating layer 19 that are sequentially stacked on the substrate 11. It has a configuration.

  The magnetic flux control layer 101 is made of a superconducting material having a thickness of 10 nm to 1000 nm using a sputtering method, a vacuum deposition method, a CVD method, a laser ablation method, or the like. The thickness is preferably 50 nm or less in the above range from the viewpoint of the spacing between the recording head (not shown) and the soft magnetic backing layer 12, and in terms of magnetic flux leakage from the magnetic flux control layer 101, the thickness is 1 It is preferably larger than / 3.

The superconducting material used for the magnetic flux control layer 101 is not particularly limited, but YBa ₂ Cu ₃ O _7-δ (0 <δ <1), Bi ₂ Sr ₂ CaCu ₂ O having a superconducting critical temperature Tc of 90K to 125K. ₈ , oxide superconductors such as Bi ₂ Sr ₂ Ca ₂ Cu ₃ O ₁₀ and Ti ₂ Ba ₂ Ca ₂ Cu ₃ O ₁₀ , Nb ₃ Ge and Nb ₃ Al are preferable.

  Since the perpendicular magnetic recording medium 100 is cooled to the superconducting critical temperature Tc and the magnetic flux control layer 101 is in a superconducting state and is a complete diamagnetic material, the magnetic flux from the recording head can pass through the magnetic flux control layer 101. Therefore, the soft magnetic backing layer 12 cannot be reached. That is, the magnetic flux from the recording head spreads over a wide range. According to the present embodiment, a part of the magnetic flux control layer 101 is heated to change to a normal state. As a result, since the magnetic flux can pass only through the region in the normal conduction state, the magnetic flux can be concentrated in the region and the magnetic flux can be concentrated in the recording layer 16.

  Hereinafter, a recording / reproducing method of the perpendicular magnetic recording medium 100 of the present embodiment will be described.

  FIG. 28 is a diagram showing a state of recording on the perpendicular magnetic recording medium according to the present embodiment. A composite magnetic head 110 disposed to face the perpendicular magnetic recording medium 100 includes a main magnetic pole 111, a recording coil 113 that excites the main magnetic pole 111, and a return yoke 112 that is magnetically connected to the main magnetic pole 111. A recording head, a reproducing head composed of a magnetosensitive element 115 such as an MR element, a shield 114, and the like, and a laser light source 117 such as a semiconductor laser are connected, the tip is narrowed down, and a light beam LB is applied to the surface of the perpendicular magnetic recording medium 100. It is comprised from the optical fiber 116 etc. which irradiate. The magnetic head 110 and the perpendicular magnetic recording medium 100 are housed in a thermostat or thermostat (not shown) and maintained in an atmosphere having a critical temperature Tc or lower.

  When recording information on the perpendicular magnetic recording medium 100, in addition to applying a recording magnetic field, the magnetic flux from the recording head 110 is changed by changing the region of the magnetic flux control layer 101 below the main magnetic pole 111 and the return yoke 112 to the normal conduction state. The recording layer 16 is magnetized so as to be refluxed between the recording head 110 and the soft magnetic underlayer 12. Specifically, the surface of the perpendicular magnetic recording medium 100 is irradiated with an optical fiber on the upstream side of the perpendicular magnetic recording medium 100 moving in the arrow direction Mv, and the magnetic flux control layer 101 is heated to the critical temperature Tc or higher by heat conduction. By heating, the region 101a in the normal conduction state is formed. The output and wavelength of the light beam are appropriately selected depending on the temperature of the perpendicular magnetic recording medium 100 and the heating temperature. For example, the power is set to several mW or less and the beam diameter is set to 1 μm or less.

  Here, since heating is performed with only one beam, the region 101a in the normal conduction state is in the normal conduction region 101a downstream from the boundary portion 101c with the superconducting state 101b in the upstream region. Accordingly, since the magnetic flux control layer 101 immediately below the main magnetic pole 111 and the return yoke 112 is in a normal conduction state and in a nonmagnetic state, for example, the magnetic flux from the main magnetic pole 111 is recorded layer 16a-magnetic flux control layer 101-soft. It flows to the return yoke 112 through the magnetic backing layer 12 -the magnetic flux control layer 101 -the recording layer 16b. As a result, the recording layer 16a facing the main magnetic pole 111 is magnetized.

  FIG. 29 is a diagram for explaining the state of the magnetic flux control layer as viewed from the composite magnetic head side shown in FIG. The perpendicular magnetic recording medium 100 moves in the arrow direction Mv, and the upstream side is shown to be the right side of the figure. Further, tracks Tkn-1 to Tkn + 1 formed on the recording layer 16 are also shown.

  Referring to FIG. 29, the magnetic flux control layer 101 is heated by the light beam LB irradiated by the optical fiber, and a normal conduction region 101a is formed in a part of the superconducting region 101b with the boundary 101c as a boundary. The The region 101a in the normal conduction state is greatly widened in the track width direction on the upstream side and becomes narrower toward the downstream side. In the region facing the main magnetic pole 111, the track width direction is set to be substantially equal to the track width. Is done. Therefore, the magnetic flux from the main magnetic pole 111 passes through the recording layer 16 with the track width direction being limited, and does not affect the magnetization of the adjacent tracks Tkn−1 and Tkn + 1. As a result, erasure of adjacent tracks can be prevented, and the track density can be improved.

  In addition, in the case of one beam in the longitudinal direction of the track, the magnetic flux cannot be narrowed down to the extent of the 1-bit magnetization region sandwiched by the magnetization transition region because the region 101a in the normal conduction state has a spread. Therefore, the magnetic flux density, that is, the recording magnetic field is strengthened, and the writing performance such as the overwrite characteristic and the NLTS characteristic is improved.

  Note that laser light may be condensed on the surface of the perpendicular magnetic recording medium 100 using a microlens instead of the optical fiber.

  Returning to FIG. 28, when reproducing the information recorded on the perpendicular magnetic recording medium 100, the magnetosensitive element of the reproducing head detects the leakage magnetic field from the magnetized recording layer 16 as in the conventional perpendicular magnetic recording medium. To do. In the case where only the reproducing operation is performed, the magnetic flux control layer 101 may be in a normal conduction state.

  The main magnetic pole 111 and the return yoke 112 may be separated from each other, and another optical fiber may be provided between the main magnetic pole 111 and the return yoke 112 to irradiate two light beams for the main magnetic pole and the return yoke. . Specifically, the light beam for the return yoke is set so that a large-diameter normal conduction region as shown in FIG. 29 is formed, and the normal conduction state is formed by heating with the main magnetic pole light beam. Is set to about the thickness x width of the main magnetic pole 111. Further, the main pole 111 and the return yoke 112 are separated from each other to separate the normal state region for the return yoke and the normal state region for the main pole. With such a configuration, the magnetic flux density from the main magnetic pole 111, that is, the recording magnetic field can be further increased, and the recording magnetic field gradient can be made steep.

  Hereinafter, the effect of the perpendicular magnetic recording medium according to the present embodiment was obtained by calculation.

  FIG. 30A is a diagram illustrating a state in which magnetic flux is applied from the main magnetic pole of the recording head to the perpendicular magnetic recording medium of the example according to the present embodiment, and FIG. 30B is a diagram illustrating the main of the recording head in the perpendicular magnetic recording medium according to the comparative example. It is a figure which shows a mode that a magnetic flux is applied from a magnetic pole. For convenience of explanation, the protective film 18 and the lubricating layer 19 are omitted.

  Referring to FIG. 30A, in the perpendicular magnetic recording medium according to the example, when the normal conduction region formed in the magnetic flux control layer 101 by heating is a region equivalent to or narrower than the main magnetic pole 111, it is formed by the mirror image effect. It is considered that the virtual magnetic pole MP1 with respect to the main magnetic pole 111 is formed on the surface of the soft magnetic backing layer 12 because the magnetic flux is narrowed down to the normal conduction region. Therefore, the magnetic flux MF1 is concentrated in the recording layer 16. The spacing is a distance SP between the main magnetic pole 111 and the virtual magnetic pole MP1.

  On the other hand, referring to FIG. 30B, the perpendicular magnetic recording medium according to the comparative example does not include a magnetic flux control layer between the soft magnetic backing layer 12 ′ and the recording layer 16 ′. Is spread toward the soft magnetic backing layer 12 ′, and the virtual magnetic pole MP2 is symmetrical between the main magnetic pole 111 and the soft magnetic backing layer surface 12a ′ from the surface 12a ′ symmetrically with respect to the surface 12a ′ of the soft magnetic backing layer 12 ′. It is formed downward by a distance SP. Therefore, the distance between the main magnetic pole 111 and the virtual magnetic pole MP2 is 2 × SP.

  The relationship between the signal-to-noise ratio (S / Nm) including the linear recording density dependency and the spacing is assumed as shown in the following table. When the rate of change of S / Nm in the table below is negative, it indicates that S / Nm decreases with increasing spacing.

<Linear recording density><Change rate of S / Nm per 1 nm of spacing>
200 kFCI -0.1 dB / nm
370 kFCI -0.3 dB / nm
480 kFCI -0.4 dB / nm
As described above, when the calculation is performed using the relationship between S / Nm and the linear recording density based on the spacing between the main magnetic pole 111 and the virtual magnetic poles MP1 and MP2, the following results are obtained. Here, it was assumed that the distance SP = 50 nm. The increase in S / Nm in the table below indicates the increase in S / Nm of the example relative to the comparative example, and the positive value indicates that the S / Nm is higher in the example than in the comparative example.

<Linear recording density><Increase in S / Nm>
200 kFCI 5 dB
300 kFCI 10 dB
400 kFCI 15 dB
500 kFCI 20 dB
600 kFCI 25 dB
From the above table, it can be seen that the S / Nm is greatly improved in the examples. Therefore, by providing the magnetic flux control layer 101 between the soft magnetic backing layer 12 and the recording layer 16, S / Nm can be improved and high density recording can be achieved.

  The recording layer 16 of this embodiment is the same as the recording layer 16 described in the first or second embodiment, but the perpendicular magnetic recording medium 100 according to this embodiment is used at a critical temperature Tc or lower. For example, since the critical temperature Tc of a superconducting material found at present is a low temperature of about 120 K or lower, the degree of demagnetization due to thermal stability is small. Therefore, the volume limit of the magnetic particles is relaxed compared to the conventional perpendicular magnetic recording medium, the magnetic particles constituting the recording layer 16 can be further miniaturized, and the medium noise can be reduced more easily. it can.

  Note that the nonmagnetic intermediate layer 15 shown in FIG. 1 described in the first embodiment may be laminated between the magnetic flux control layer 101 and the recording layer 16. Since the ferromagnetic material constituting the recording layer 16 is difficult to epitaxially grow on the magnetic flux control layer 101, the provision of the nonmagnetic intermediate layer 15 improves the crystallinity and crystal orientation of the recording layer 16 and further increases the medium noise. Can be reduced. Further, the seed layer 13 and the underlayer 31 shown in FIGS. 1 and 2 may be provided between the magnetic flux control layer 101 and the nonmagnetic intermediate layer 15. The crystallinity and crystal orientation of the recording layer 16 can be further improved.

As an example according to this embodiment, glass substrate / CoNbZr film (120 nm) / YBa ₂ Cu ₃ O _7-δ film (20 nm) / Ta film (1 nm) / Ru film (2 nm) / (Co ₇₆ Cr ₉ Pt ₁₅ ) 90 vol%-(SiO ₂ ) 10 vol% film (10 nm) / carbon film (4 nm) / AM3001 film (1.5 nm) were formed. The AM3001 film was formed by a pulling method, and the other films were formed by a sputtering method. The numerical value in the parenthesis represents the film thickness.

  As a modification of the present embodiment, a perpendicular magnetic recording medium in which a magnetic flux control layer made of a superconducting material is provided on a recording layer will be described.

  FIG. 31 is a schematic cross-sectional view of a perpendicular magnetic recording medium according to a modification of the seventh embodiment. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 31, the perpendicular magnetic recording medium 105 has a substrate 11 and a soft magnetic backing layer 12, a recording layer 16, a magnetic flux control layer 106, a protective film 18, and a lubricating layer 19 sequentially laminated on the substrate 11. It has a configuration.

  The magnetic flux control layer 106 provided on the recording layer 16 is formed in the same manner as the magnetic flux control layer 101 of the present embodiment, and the recording method is also the same. However, the output of the light beam LB and the beam size shown in FIGS. 28 and 29 are appropriately adjusted according to the type and film thickness of the superconducting material of the magnetic flux control layer 106.

  When reproducing the perpendicular magnetic recording medium according to this modification, a normal beam region is formed in the magnetic flux control layer 106 by irradiating a light beam in the same manner as the recording method shown in FIGS. Reproduction is performed by detecting a leakage magnetic field from the magnetization of 16 through a normal conduction region of the magnetic flux control layer 106 and detecting the magnetosensitive element of the reproducing head (not shown).

  According to this modification, the magnetic flux can be confined between the recording head and the recording layer 16, the recording magnetic field is high, and the recording magnetic field gradient can be increased.

  In this embodiment, the light beam is irradiated from the front surface of the perpendicular magnetic recording media 100 and 105, but may be irradiated from the back surface.

(Eighth embodiment)
A magnetic flux slit layer made of a superconducting material that fills a gap between adjacent tip-like nonmagnetic materials, and a tip-like nonmagnetic material made of a nonmagnetic material that is arranged substantially uniformly between the soft magnetic backing layer and the recording layer. A perpendicular magnetic recording medium according to an eighth embodiment of the present invention provided with

  FIG. 32A is a schematic sectional view of a perpendicular magnetic recording medium according to the eighth embodiment of the present invention, and FIG. 32B is a sectional view taken along line XX of FIG. 32A. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  32A and 32B, the perpendicular magnetic recording medium 140 includes a substrate 11 and a soft magnetic backing layer 12, a magnetic flux slit layer 141, a recording layer 16, a protective film 18, and a lubricating layer 19 on the substrate 11. It is the structure which laminated | stacked one by one.

  The magnetic flux slit layer 101 has a thickness of 2 nm to 10 nm, and is a complete diamagnetic material portion in which the gap between the tip-shaped nonmagnetic material 141a made of a nonmagnetic material and the adjacent tip-shaped nonmagnetic material 141a is filled with a superconductive material. 141b. The nonmagnetic material used for the tip-shaped nonmagnetic material 141a is selected from nonmagnetic materials such as Co, Cr, Ru, Re, Ri, Hf, and alloys thereof, and preferably has an hcp structure. When the recording layer 16 has an hcp structure, it can be epitaxially grown. The tip-shaped nonmagnetic material 141a has a size of, for example, 0.6 nm to 20 nm × 0.6 nm to 20 nm, and a gap GP between adjacent tip-shaped nonmagnetic materials 141a is configured to be 0.6 nm to 20 nm.

  In addition, examples of the superconducting material used for the complete diamagnetic part 141b include the same materials as those used for the magnetic flux control layer of the seventh embodiment.

  The magnetic flux slit layer 101 can be formed in substantially the same manner as the tip-like magnetic body of the sixth embodiment. That is, a non-magnetic film to be a tip-like non-magnetic body 141a is formed on the soft magnetic backing layer 12, a mask is prepared using an electron beam resist film and an electron beam batch projection exposure method, and etched to form a tip-like non-magnetic body. 141a is formed. Next, a superconducting material film is formed to cover the tip-shaped nonmagnetic material 141a, and is ground and planarized using a CMP method or the like until the tip-shaped nonmagnetic material 141a is exposed.

  The perpendicular magnetic recording medium 140 of this embodiment is used in an atmosphere having a critical temperature Tc or lower as in the seventh embodiment, and the complete diamagnetic part 141b is used in a superconducting state. The magnetic flux from the recording head cannot pass through the complete diamagnetic part 141b at all, but passes through the tip-like nonmagnetic substance 141a. Therefore, since the magnetic flux from the recording head is concentrated on the tip-shaped nonmagnetic material 141a, the magnetic flux can be concentrated on the recording layer 16.

  Note that the tip-shaped nonmagnetic material 141a may be formed using a soft magnetic material in terms of further concentrating the magnetic flux.

  Further, unlike the perpendicular magnetic recording medium according to the seventh embodiment, the perpendicular magnetic recording medium 140 according to the present embodiment can perform recording and reproduction without using a light beam, so that the configuration of the magnetic head is improved. It is preferable in terms of simplicity.

(Ninth embodiment)
A ninth magnetic storage device of the present invention provided with the perpendicular magnetic recording media according to the first to sixth embodiments will be described.

  FIG. 33 is a diagram showing a main part of the magnetic memory device according to the embodiment of the present invention. Referring to FIG. 33, the magnetic storage device 120 generally includes a housing 121. Inside the housing 121 is a hub 122 driven by a spindle (not shown), a perpendicular magnetic recording medium 123 fixed to the hub 122 and rotated, an actuator unit 124, and a radius of the perpendicular magnetic recording medium 123 attached to the actuator unit 124. An arm 125 and a suspension 126 which are moved in the direction are provided, and a perpendicular magnetic recording head 128 supported by the suspension 126 is provided.

  FIG. 34 is a schematic sectional view of a perpendicular magnetic recording head and a perpendicular magnetic recording medium. Referring to FIG. 34, the perpendicular magnetic recording head 128 is generally composed of a recording head 130 including a main magnetic pole 135 and a return yoke 136 and a reproducing head 131 using a GMR (Giant Magnet Resistive) element 133. The recording head 130 includes a main magnetic pole 135 made of a soft magnetic material for applying a recording magnetic field to the perpendicular magnetic recording medium 123, a return yoke 136 magnetically connected to the main magnetic pole 135, a recording magnetic field on the main magnetic pole 135, and the like. For example, a recording coil 138 for guiding. The reproducing head 131 includes a GMR element 133 sandwiched between a lower shield using a return yoke 136 and an upper shield 137.

  The recording head 130 applies a recording magnetic field in the perpendicular direction to the perpendicular magnetic recording medium 123 from the tip portion 135-1 of the main magnetic pole to form perpendicular magnetization in the recording layer (not shown). Note that the magnetic flux from the tip portion 135-1 of the main magnetic pole returns to the return yoke 136 through the soft magnetic underlayer (not shown). The soft magnetic material of the tip portion 135-1 of the main pole is preferably made of a high saturation magnetic flux density, for example, 50 at% Ni-50 at% Fe, FeCoNi alloy, FeCoAlO, or the like. Magnetic saturation can be prevented and a magnetic flux having a high magnetic flux density can be concentrated and applied to the recording layer 130.

  Further, the reproducing head 131 can sense the magnetic field in which the magnetization of the perpendicular magnetic recording medium 123 leaks, and obtain information recorded on the recording layer by the change in the resistance value of the GMR element 133 corresponding to the direction. Instead of the GMR element 133, a TMR (Ferromagnetic Tunnel Junction Magneto Resistive) element or a ballistic MR element can be used.

  The magnetic storage device 120 of this embodiment is characterized by a perpendicular magnetic recording medium 123. For example, the perpendicular magnetic recording medium 123 is a perpendicular magnetic recording medium according to the first to sixth embodiments and modifications thereof.

  The basic configuration of the magnetic storage device 120 is not limited to that shown in FIG. The perpendicular magnetic recording medium 123 used in the present invention is not limited to a magnetic disk but may be a magnetic tape.

  According to the present embodiment, the magnetic storage device 120 is configured such that the perpendicular magnetic recording medium 123 narrows the magnetic flux from the main magnetic pole 135 of the recording head 130 and concentrates it on the recording layer, thereby narrowing the track and reducing the linear recording density. Can be improved, and high-density recording is possible.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the present invention described in the claims. It can be changed.

  For example, in the magnetic storage device according to the ninth embodiment, the magnetic disk is described as an example of the perpendicular magnetic recording medium. However, the perpendicular magnetic recording medium of the present invention is not limited to the magnetic disk, and the substrate is PET or PEN. Further, a helical scan or lateral running type magnetic tape using a film made of polyimide may be used, or a card form may be used.

1 is a schematic cross-sectional view of a perpendicular magnetic recording medium according to a first embodiment of the invention. It is a schematic sectional drawing of the perpendicular magnetic recording medium based on the modification of 1st Embodiment. It is a schematic sectional drawing of the perpendicular magnetic recording medium which concerns on the 2nd modification of 1st Embodiment. FIG. 6 is a diagram showing the characteristics of perpendicular magnetic recording media according to Examples 1 and 2 and Comparative Example 1. 6 is a diagram showing S / Nm characteristics of perpendicular magnetic recording media according to Example 3 and Comparative Example 2. FIG. It is a schematic sectional drawing of the perpendicular magnetic recording medium based on the 2nd Embodiment of this invention. 6 is a schematic diagram of a TEM photograph in plan view of a recording layer of a perpendicular magnetic recording medium according to Example 4. FIG. 6 is a schematic diagram of a TEM photograph in plan view of a recording layer of a perpendicular magnetic recording medium according to Example 5. FIG. 10 is a schematic diagram of a TEM photograph in plan view of a recording layer of a perpendicular magnetic recording medium according to Comparative Example 3. FIG. FIG. 6 is a diagram showing the characteristics of perpendicular magnetic recording media according to Examples 4 and 5. It is a schematic sectional drawing of the perpendicular magnetic recording medium based on the 3rd Embodiment of this invention. It is a figure which shows the mode of recording of the perpendicular magnetic recording medium based on 3rd Embodiment. It is the figure which planarly viewed FIG. It is a figure which shows the mode of reproduction | regeneration of the perpendicular magnetic recording medium based on 3rd Embodiment. FIG. 13 is a plan view of FIG. 12. It is a figure which shows typically the film-forming apparatus which orientates an easy axis of magnetization by applying a magnetic field. It is a figure which shows typically the film-forming apparatus which injects a sputtered particle diagonally and orients an easy axis of magnetization. It is a schematic sectional drawing of the perpendicular magnetic recording medium based on the modification of 3rd Embodiment. It is a figure which shows the relationship between S / Nm of Example 6, and a soft-magnetic shielding layer film thickness. It is a figure which shows the relationship between the reproduction output fall rate of Example 6 and the soft-magnetic shielding layer film thickness in an adjacent track erase test. It is a figure which shows the relationship between S / Nm of Example 6, and a recording current. It is a figure which shows the relationship between S / Nm of Example 7, and a nonmagnetic layer film thickness. It is a schematic sectional drawing of the perpendicular magnetic recording medium based on the 4th Embodiment of this invention. It is a schematic sectional drawing of the perpendicular magnetic recording medium based on the 5th Embodiment of this invention. It is a schematic sectional drawing of the perpendicular magnetic recording medium based on the modification of 5th Embodiment. It is a schematic sectional drawing of the perpendicular magnetic recording medium based on the 6th Embodiment of this invention. It is a top view of the perpendicular magnetic recording medium based on 6th Embodiment. It is a top view of the perpendicular magnetic recording medium based on the modification of 6th Embodiment. It is a schematic sectional drawing of the perpendicular magnetic recording medium based on the 7th Embodiment of this invention. It is a figure which shows a mode that it records on the perpendicular magnetic recording medium based on 7th Embodiment. It is a figure for demonstrating the state of the magnetic flux control layer seen from the perpendicular magnetic recording-medium composite magnetic head side shown in FIG. It is a figure which shows a mode that a magnetic flux is applied to the perpendicular magnetic recording medium of the Example which concerns on this Embodiment from the main pole of a recording head. It is a figure which shows a mode that a magnetic flux is applied to the perpendicular magnetic recording medium which concerns on a comparative example from the main pole of a recording head. It is a schematic sectional drawing of the perpendicular magnetic recording medium based on the modification of 7th Embodiment. It is a schematic sectional drawing of the perpendicular magnetic recording medium based on the 8th Embodiment of this invention. It is XX sectional drawing of FIG. 32A. It is a figure which shows the principal part of the magnetic storage apparatus of the 9th Embodiment of this invention. 1 is a schematic cross-sectional view of a perpendicular magnetic recording head and a perpendicular magnetic recording medium.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Substrate 12 Soft magnetic backing layer 16 Recording layer 18 Protective film 19 Lubricating layer 100 Perpendicular magnetic recording medium 101 Magnetic flux control layer 110 Composite magnetic head 111 Main magnetic pole 113 Recording coil 116 Fiber 117 Laser light source

Claims (8)

A soft magnetic backing layer, and a recording layer provided above the soft magnetic backing layer,
A perpendicular magnetic recording medium in which a magnetic flux from a recording head flows through the recording layer to a soft magnetic backing layer and is magnetized.
A magnetic flux control layer including a superconductive material between the soft magnetic backing layer and the recording layer;
A perpendicular magnetic recording medium, wherein a normal conduction region is formed in a part of the superconducting magnetic flux control layer to pass the magnetic flux.   2. The perpendicular magnetic recording medium according to claim 1, wherein a part of the superconducting magnetic flux control layer is changed to form a normal conducting region.   2. The perpendicular magnetic recording medium according to claim 1, wherein the normal conducting region is made of a nonmagnetic material which is a normal conductor.   4. The perpendicular magnetic recording medium according to claim 3, wherein the normal-conducting region is substantially rectangular or substantially circular, and has a side or diameter in the range of 0.6 nm to 20 nm. The superconductive materials are YBa ₂ Cu ₃ O _7-δ , Bi ₂ Sr ₂ CaCu ₂ O ₈ , Bi ₂ Sr ₂ Ca ₂ Cu ₃ O ₁₀ , Ti ₂ Ba ₂ Ca ₂ Cu ₃ O ₁₀ , Nb ₃ Ge, and a perpendicular magnetic recording medium according to claim 1, wherein the Nb is one material or of the group consisting of ₃ Al. A perpendicular magnetic recording medium having a soft magnetic backing layer and a recording layer provided above the soft magnetic backing layer, and having a magnetic flux control layer containing a superconducting material between the soft magnetic backing layer and the recording layer. Heating a region of the magnetic flux control layer in a superconducting state;
Applying a recording magnetic field to the region,
A recording method of changing the region to a normal state by the heating.   The recording method according to claim 6, wherein the heating is performed by trading a light beam. The perpendicular magnetic recording medium according to any one of claims 1 to 5,
Heating means for selectively heating the surface of the perpendicular recording medium;
A magnetic storage device comprising recording means for recording information on the recording layer,
During recording, the heating means heats a part of the magnetic flux control layer in a superconducting state to change to a normal state, and passes the magnetic flux to the part of the normal state made by the recording means. And recording information on a recording layer.

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