JP2002358627A - Magnetic recording medium and magnetic storage element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic recording medium whose high frequency characteristics is improved and to provide a magnetic storage element wherein the perpendicular squareness ratio is 1 and the transition area of the magnetic domain is clear and as a result, the magnetization of a fine area can be stably maintained. SOLUTION: The magnetic recording medium or the magnetic storage device is characterized in that a perpendicular magnetization film containing both B and O and formed by mutually laminating Pt layers or Pd layers and Co layers is formed on a single crystalline substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hard disk,
A magnetic recording medium used for a magnetic tape, a floppy (registered trademark) disk, a magneto-optical disk, etc., and a magnetic recording / reproducing apparatus for recording / reproducing information on / from the magnetic recording medium;
Also, the present invention relates to a magnetic storage element that performs storage by controlling the direction of magnetization of a magnetic material.

[0002]

2. Description of the Related Art In longitudinal magnetic recording, there has been a problem of thermal demagnetization in which recording magnetization decays with time as recording density increases. In recent years, attention has been paid to perpendicular magnetic recording as a method for solving this problem. CoCr alloys have been widely studied as magnetic materials for such perpendicular magnetic recording. However, since the perpendicular magnetic anisotropy of the CoCr alloy is smaller than the saturation magnetization, the perpendicular squareness ratio does not become 1. Therefore, there is a problem that a reversal magnetization region is generated in a long wavelength recording portion, which causes noise. In order to solve such a problem, it is known that it is appropriate to use a material having a large perpendicular magnetic anisotropy, such as an artificial lattice film in which a Co layer and a Pt layer or a Pd layer are laminated. However, such a laminated film has a problem that it has a large amount of transition noise and is not suitable for short-wavelength recording.

In order to solve this problem, Omori, one of the present inventors, has proposed that (a) Pt, A
u, Pd and other metals having a face-centered cubic structure, and (b) SiO ₂ ,
By using a composite film with an oxide such as Al ₂ O ₃ , a nitride such as TiN or BN, or a carbide such as TaC, the isolation of magnetic particles in the magnetic layer is improved, and as a result, transition noise is significantly reduced. (Japanese Patent Application No. 11-340277). Further, the present inventors have improved the isolation of magnetic particles in a perpendicular magnetic recording medium using such an artificial lattice film, rather than mixing B and O elements into the artificial lattice film of the Co layer and the Pt layer or the Pd layer. And disclosed that it is possible to significantly reduce transition noise (Japanese Patent Application No. 2000-200370).

[0004] In the perpendicular magnetic recording medium according to the above two inventions, the transition noise is remarkably reduced, and as a result, the short-wavelength recording is improved over the conventional laminated film. Therefore, there is room for further improvement in the above-described perpendicular magnetic recording medium so that the high-frequency characteristics are improved.

On the other hand, a magnetic storage element that performs storage by controlling the direction of magnetization of a minute region of a magnetic body has been studied (Japanese Patent Laid-Open No. 04-359152). One of the most important issues in a magnetic memory element is to stably maintain the magnetization of a minute region. When a perpendicular magnetic film is used in a magnetic storage element, it is required that the perpendicular squareness ratio is 1 and the transition region of the magnetic domain is clear, as in the perpendicular magnetic recording medium. However, in the prior art, when a CoCr alloy is used, there is a problem that the perpendicular squareness ratio does not become 1 because the perpendicular magnetic anisotropy is smaller than the saturation magnetization. When an artificial lattice film in which a Co layer and a Pt layer or a Pd layer are stacked is used, the perpendicular squareness ratio is 1, and although the above problem has been solved, the transition region of the magnetic domain is not clearly defined. Problems have arisen.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording medium having further improved high frequency characteristics. Another object of the present invention is to provide a magnetic memory element having a perpendicular squareness ratio of 1 and a clear transition region of a magnetic domain, and as a result, capable of stably retaining the magnetization of a minute region. I do.

[0007]

In order to achieve the above object, the present inventors include both B and O in an artificial lattice perpendicular magnetization film in which a Pt layer or a Pd layer and a Co layer are alternately stacked. Analysis of a known perpendicular magnetization film (Japanese Patent Application No. 2000-200370) revealed that minute inverted magnetic domains having a size of 0.1 to 0.2 μm were generated. It has been found that such a small inversion magnetic domain causes a decrease in high frequency characteristics, and that the presence of such a small inversion magnetic domain in the transition region of the magnetic domain makes the transition region of the magnetic domain unclear. Therefore, the object of the present invention can be achieved by suppressing minute switching domains in the known perpendicular magnetization film.

Based on the above findings, the present inventors diligently studied means for suppressing minute switching domains in the known perpendicular magnetization film. And although a glass substrate was used in the above-mentioned known perpendicular magnetization film, the orientation of the artificial lattice perpendicular magnetization film was uniform over the entire surface by using a single crystal substrate instead of the glass substrate, and the distribution of perpendicular anisotropy was obtained. Became uniform, and the unexpected finding that the reversal magnetic domain can be suppressed was obtained. As a result, high frequency characteristics are improved,
It is possible to obtain a magnetic recording medium with further improved high-frequency characteristics as compared with the related art. Further, the transition region of the magnetic domain becomes clear, and a magnetic storage element capable of stably holding the magnetization of the minute region can be obtained. Further, the present inventors have repeatedly studied,
The present invention has been completed.

That is, the present invention provides (1) a perpendicular magnetization film in which (a) a Pt layer or a Pd layer containing B and O and (b) a Co layer containing B and O are alternately laminated. Is a film formed on a single-crystal substrate, (2) the single-crystal substrate is a cubic (111) -oriented single-crystal substrate, (3) The magnetic recording medium according to (2), wherein the cubic (111) oriented single crystal substrate is an oxide single crystal substrate. (4) An oxide single crystal The substrate is
(3) The magnetic recording medium of (3), which is made of MgO, NiO or SrTiO ₃ , (5) a cubic (111) oriented single crystal substrate using a semiconductor single crystal substrate. 2) the magnetic recording medium, (6)
The magnetic recording medium according to the above (5), wherein the semiconductor single crystal substrate is made of Si.

Further, according to the present invention, (7) an underlayer is formed on a single crystal substrate, and (a) B and O
(8) a magnetic recording medium comprising: a perpendicular magnetization film formed by alternately laminating a Pt layer or a Pd layer containing: and (b) a Co layer containing B and O; The magnetic recording medium according to the above (7), wherein the single crystal substrate is a cubic (111) oriented single crystal substrate.
(9) The magnetic recording medium of (8), wherein the cubic (111) oriented single crystal substrate is an oxide single crystal substrate, (10) the oxide single crystal substrate is formed of MgO, Ni
The present invention relates to the magnetic recording medium according to the above (9), which is made of O or SrTiO ₃ .

The present invention also provides (11) cubic (1)
(11) The magnetic recording medium according to (8), wherein the oriented single crystal substrate is a semiconductor single crystal substrate.
(11) The magnetic recording medium according to (11), wherein the semiconductor single crystal substrate is made of Si; and (13) the underlayer is made of an underlayer material containing a metal element having a face-centered cubic structure. (14) The magnetic recording medium according to (13), wherein the base material further contains both B and O, and (15) a metal element having a face-centered cubic structure. Are Pd, Pt, Au, Pd, Ag,
The magnetic recording medium according to (13), wherein the magnetic recording medium is Rh or Ir.

The present invention also provides (16) the above (1) to
(15) The magnetic recording medium according to any one of (15), a holder for holding the magnetic recording medium, a magnetic head for recording / reproducing information on / from the magnetic recording medium, and a magnetic head for recording / reproducing information on / from the magnetic recording medium. A magnetic recording device having moving means for moving the relative position and control means for controlling these components; (17) a magnetic head for recording and reproducing information is a thin film ring head; (16) The magnetic recording device according to the above (16), (18) the magnetic head for recording information is a thin film ring head, and the magnetic head for reproducing information is a magnetoresistive head. (16) The magnetic recording device according to (16), wherein the magnetic head for recording and reproducing information is a single-pole head. The magnetic recording apparatus according,
(20) The magnetic recording device according to (16), wherein the magnetic head for recording information is a single-pole head, and the magnetic head for reproducing information is a magnetoresistive head. (21) The magnetic recording device according to (16), wherein the magnetic recording medium and the magnetic head for recording and reproducing information record and reproduce information while contacting with each other. The magnetic recording apparatus according to (16), wherein the medium and a magnetic head for recording and reproducing information are arranged close to each other and record and reproduce information.

Further, the present invention relates to (23) (a) B and O
Wherein a perpendicular magnetization film formed by alternately laminating a Pt layer or a Pd layer containing B and a Co layer containing B and O is formed on a single crystal substrate. (24) The magnetic storage element according to (23), wherein the (24) single crystal substrate is a cubic (111) oriented single crystal substrate. (24) The magnetic memory element according to the above (24), wherein the crystal substrate is an oxide single crystal substrate, and (26) the magnetic storage element, wherein the oxide single crystal substrate is made of MgO, NiO or SrTiO _3. 25) A magnetic storage element.

The present invention also relates to (27) a cubic (1)
11) The magnetic memory element according to the above item (24), wherein the oriented single crystal substrate uses a semiconductor single crystal substrate.
(29) The magnetic memory element according to (27), wherein the semiconductor single crystal substrate is made of Si. (29) An underlayer is formed on the single crystal substrate, and (a) B and O (30) a magnetic storage element comprising: a perpendicular magnetization film formed by alternately laminating a Pt layer or a Pd layer containing B and (b) a Co layer containing B and O.
The magnetic memory element according to (29), wherein the single crystal substrate is a cubic (111) oriented single crystal substrate, wherein the (31) cubic (111) oriented single crystal substrate is:
(30) wherein the substrate is an oxide single crystal substrate.
(32) The oxide single crystal substrate is made of Mg
(31) The magnetic memory element according to (31), wherein the magnetic memory element is made of O, NiO or SrTiO ₃ , and (33) a cubic (111) oriented single crystal substrate using a semiconductor single crystal substrate. 30) a magnetic storage element;
4) The magnetic storage element according to (33), wherein the semiconductor single crystal substrate is made of Si.

(35) The magnetic storage element according to (29), wherein the underlayer is made of an underlayer material containing a metal element having a face-centered cubic structure.
(35) The magnetic memory element according to (35), wherein the base material further contains both B and O, wherein the metal element having the face-centered cubic structure is Pd, Pt, Au, Pd, A
g, Rh or Ir.
5) A magnetic storage element according to the present invention.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the magnetic recording medium or magnetic storage element according to the present invention will be described with reference to FIGS. As shown in FIG. 1, a magnetic recording medium or a magnetic storage element 1 according to the present invention includes a substrate 2, an adhesive layer 3 formed on the substrate 2, and a base layer 4 formed on the adhesive layer 3.
And a perpendicular magnetic film 5 formed on the underlayer 4 and a protective layer 6 formed on the perpendicular magnetic film 5. Further, as shown in FIG. 2, a soft magnetic layer 7 may be formed between the substrate 2 and the underlayer 4.

Each of the above layers will be described in detail below. Substrate 2
Is a feature of the present invention that it is a single crystal substrate. By using a single crystal substrate, the orientation of the perpendicular magnetization film formed thereon is uniform over the entire surface, so that there is an advantage that the distribution of the perpendicular anisotropy becomes uniform and the switching domain is suppressed. The structure and orientation of the crystal of the single crystal substrate are not particularly limited.
As the single crystal substrate used in the present invention, for example, A
Hexagonal single crystal substrate made of l ₂ O ₃ , Cr ₂ O ₃ , BeO or ZnO, or a material containing any of these compounds as a main component; MgO, LiF, SrTiO ₃ , C
A cubic single crystal substrate made of aF ₂ , BaF ₂ , SiC, Si or Ge, or a material containing any of these compounds as a main component may be used. In the present invention, it is particularly preferable to use a cubic (111) -oriented single crystal substrate. Among the cubic (111) -oriented single-crystal substrates, among others, oxide single-crystal substrates such as MgO, NiO, and SrTiO ₃ having a (111) orientation or semiconductor single-crystal substrates such as Si ( 11
1) It is preferable to use a substrate having an orientation.

The adhesive layer 3 is provided as desired in order to increase the bonding strength between the substrate 2 and the underlayer 4. The material of the adhesive layer 3 is not particularly limited, and may be appropriately selected depending on the types of the substrate 2 and the base layer 4. Specifically, examples of the adhesive layer 3 include a Pd, Pt, Au, Ag, Rh, Cu, or Ir layer. The thickness of the adhesive layer 3 is not particularly limited.
About nm is preferable.

The underlayer 4 is provided as desired. The underlayer 4 preferably has the same crystal orientation as the crystal orientation of the single crystal substrate. The underlying material constituting the underlying layer 4 is not particularly limited, but may be a single crystal substrate and a Co / Pd film (a film in which a Co layer and a Pd layer are alternately laminated) or a Co / Pt film (a Co layer and a Pt layer are alternately formed). It is preferable to keep the epitaxial relationship of the films stacked on the substrate. Specifically, a material containing a metal having a face-centered cubic structure is preferable. More specifically, such materials include Pd, Pt, Au,
Ag, Rh, Cu or Ir can be mentioned.
Further, it is also possible to use these alloys. These materials are particularly advantageous in that they are less susceptible to chemical changes such as oxidation and nitridation.

Further, the base material constituting the base layer 4 includes:
It is preferable that B element and O element are contained.
By containing element B and element O in the base material,
Since the isolation of the crystal grains of the underlayer is enhanced and the isolation of the crystal grains of the perpendicular magnetization film 5 formed on the underlayer 4 is also enhanced, the transition noise observed in the perpendicular magnetization film 5 is reduced, and S There is an advantage that the / N ratio can be improved.

Here, the contents of the B element and the O element in the underlayer 4 are about 1 to 30 atomic% for the B element.
About O element, about 0.1 to 30 atomic% is preferable. In order to sufficiently exhibit the above-mentioned advantages by containing the B element and the O element, the B element is contained in the base material by about 1 atomic% or more and the O element is contained by about 0.1 atomic% or more. Is preferred. On the other hand, the crystal grain size of the underlayer becomes non-uniform, and as a result, the crystal grain size of the perpendicular magnetization film 5 becomes non-uniform, and in order to avoid a decrease in S / N ratio, the B element is about 30 atomic% or less. , O element is about 30
It is preferable that about 10 atomic% or less be contained in the base material.

In the present invention, as shown in FIG. 2, a soft magnetic layer 7 may be formed immediately below the underlayer 4. It is known that a recording transition can be clearly written when a soft magnetic layer is disposed below the perpendicular magnetization film 5, but on the other hand, noise in the perpendicular magnetization film 5 often increases. Therefore, the soft magnetic layer 7
By providing the underlayer 4 between the vertical magnetization film 5 and the vertical magnetization film 5, noise generated in the vertical magnetization film 5 can be reduced. That is, the recording transition can be clearly written without increasing the noise in the perpendicular magnetization film 5 by adopting the structure shown in FIG. Here, “writing the recording transition clearly” means that the bleeding of the recording transition is reduced. The material used for the soft magnetic layer 7 is not particularly limited, and examples thereof include NiFe, CoZr, FeN, and NiFeT.

The thickness of the underlayer 4 is not particularly limited, but is preferably about 1 to 30 nm, preferably about 10 to 25 nm. In particular, when the soft magnetic layer 7 is provided immediately below the underlayer 4, the distance between the soft magnetic layer and the perpendicular magnetic film is so large that the effect of the soft magnetic layer on the perpendicular magnetic film is reduced. In order to prevent this and, on the other hand, obtain the noise reduction effect of the underlayer 4, the thickness of the underlayer 4 is preferably within the above range.

The perpendicular magnetization film 5 is composed of (a) P containing B and O
t (hereinafter also referred to as a PtBO layer) or a layer composed of Pd containing B and O (hereinafter also referred to as a PdBO layer), and (b) a layer composed of Co containing B and O (hereinafter referred to as a PdBO layer).
(Also referred to as a CoBO layer). 1 to 3, the perpendicular magnetization film 5 is formed by alternately stacking a CoBO layer having a thickness of about 0.4 nm and a PdBO layer having a thickness of about 0.6 nm. This is a preferred embodiment of the present invention and is not limited to this. For example, PdBO
A PtBO layer may be used instead of the layer.

By containing the B element and the O element in the perpendicular magnetization film 5, Pt particles or Pd
The crystallographic isolation of the particles and the Co particles is improved. The crystallographic isolation of the crystal particles causes magnetic isolation of the crystal particles. As a result, the perpendicular magnetization film 5
, The transition noise is reduced, and the S / N can be improved.

Here, the B element and O in the perpendicular magnetization film 5 are
The element content in each layer is about 1 for B element.
About 15 to 15 atomic%, and about O element about 0.1 to 10 atomic%. In order to sufficiently exhibit the above advantages by containing the B element and the O element, it is preferable that the B element is contained at about 1 atomic% or more and the O element is contained at about 0.1 atomic% or more. On the other hand, when the excess B element and O element enter the crystal grains, the perpendicular magnetic anisotropy deteriorates, and as a result, the perpendicular squareness ratio becomes 1 or less, and S
In order to avoid a decrease in the / N ratio, it is preferable that the B element is contained in about 15 atomic% or less and the O element is contained in about 10 atomic% or less.

The perpendicular magnetization film 5 may be divided into a plurality of portions by a dividing layer 8 as shown in FIG. By providing the dividing layer 8 in this manner, there is an advantage that the growth of crystal grains of the perpendicular magnetization film 5 is suppressed, and an increase in noise is suppressed even when the perpendicular magnetization film 5 is thick. Examples of the material forming the dividing layer 8 include Pd, Pt, Au, Ag, and R.
It is preferable to use a metal having a face-centered cubic structure such as h, Cu or Ir.

The thickness of the dividing layer 8 is preferably about 0.3 to 10 nm. In order to obtain a sufficient noise reduction effect, the thickness of the separation layer 8 is preferably about 0.3 nm or more. In order to perform sufficient recording during high-density recording, the thickness of the separation layer 8 is preferably about 10 nm or less. preferable.

In the perpendicular magnetization film 5, a CoBO layer and
When alternately stacking a PtBO layer or a PdBO layer, the number of layers is not particularly limited. However, each of the CoBO layer and the PtBO layer or the PdBO layer is approximately 20
It is preferable that the layers are stacked to a certain degree. Further, the number of layers of the dividing layer 8 is not particularly limited. However, two split layers 8 are provided and Co
It is preferable that the perpendicular magnetization film 5 composed of the BO layer and the PtBO layer or the PdBO layer be divided into three portions.

The protective layer 6 is formed on the perpendicular magnetization film 5. As a material of the protective layer 6, for example, C can be used. The thickness of the protective layer 6 is not particularly limited, but is preferably about 10 nm.

The magnetic recording medium or magnetic storage element according to the present invention can be easily manufactured by a method known per se. Specifically, for example, after performing a pretreatment such as cleaning the single crystal substrate by light etching or the like as desired, the above layers are formed on the single crystal substrate. The film formation method is not particularly limited. For example, physical vapor deposition (PV) such as sputtering or vacuum evaporation is used.
D), chemical vapor deposition (CVD), liquid phase epitaxy (LPE), and the like. In the present invention, it is particularly preferable to form a film by sputtering. At the time of film formation, the orientation of the crystal of the single crystal substrate, the orientation of the perpendicular magnetization film, and the orientation of the crystal of the underlayer when the underlayer is present,
Preferably they are identical.

A magnetic recording / reproducing apparatus according to the present invention includes the above-described magnetic recording medium according to the present invention, a holder for holding the magnetic recording medium, and a magnetic head for recording / reproducing information on / from the magnetic recording medium. It is characterized by comprising moving means for moving the relative position of the magnetic head and the magnetic recording medium, and control means for controlling these components. The magnetic head includes (a) a thin film ring head for recording and reproducing information, (b) a thin film ring head for recording information, and a magnetoresistive head for reproducing information; It is preferable to employ any one of a single pole head for recording and reproduction, (d) a single pole head for recording information, and a magnetoresistive head for reproducing information.

In the magnetic recording apparatus according to the present invention, the magnetic recording medium according to the present invention and a magnetic head for recording and reproducing information record or reproduce information while contacting each other. A feature is that the magnetic recording medium according to the present invention and a magnetic head for recording and reproducing information are arranged close to each other to record and reproduce information. The magnetic recording device according to the present invention may have a known structure as long as it has the above features.

[0034]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. [Example 1] An MgO (111) substrate was used as a single crystal substrate. The surface of such a substrate was cleaned by sputter etching before film formation. On the single crystal substrate, an underlayer (thickness: 10 nm) made of PdBO is further formed on top of Co.
BO layer (0.4 nm thick) and PdBO layer (0.6 nm thick)
and m) were alternately laminated by 20 layers to form an artificial lattice film by a sputtering method, thereby producing a magnetic recording medium according to the present invention. More specifically, as shown in FIG. 4, sputtering is performed in an (Ar + O ₂ ) atmosphere with Co and Pd metals (diameter 10 cm) used as sputter targets and B chips (1 cm square) placed on each target. A film was formed. As sputtering conditions, the sputtering gas pressure was 2 Pa
And the mass flow ratio of Ar and O ₂ (O ₂ / Ar) is 0.2
%.

Comparative Example 1 MgO (1) was used as a single crystal substrate.
11) Example 1 except that a 2.5-inch glass disk was used instead of the substrate, and an underlayer (20 nm in thickness) made of Pd was used instead of the underlayer made of PdBO.
And a magnetic recording medium was produced.

The magnetic properties of the magnetic recording media obtained in Example 1 and Comparative Example 1 are shown in the following table. FIG. 5 shows a magnetization curve of the magnetic recording medium. The magnetization curve was measured with a sample vibration magnetometer (VSM), and the magnetic field was applied in the direction perpendicular to the film surface. The perpendicular magnetic anisotropy of the magnetic recording medium according to the present invention was even larger than that of Comparative Example 1, and the coercive force was 4.2 kOe, which was larger than that of Comparative Example 1 (3.4 kOe).

[0037]

[Table 1]

After magnetic domains were formed on the magnetic recording media obtained in Example 1 and Comparative Example 1, the shape of the magnetic domains was observed using a deflection microscope. As a result, in the magnetic recording medium of Comparative Example 1, although the perpendicular squareness ratio was 1, the inverted magnetic domain having a size of 0.1 to 0.2 μm was 1 μm in the magnetic domain or in the transition region of the magnetic domain.
^{One to two} were observed per two. On the other hand, in the magnetic recording medium of Example 1, 0.1 to 0.2 μm observed in Comparative Example 1 was used.
No m-size reversed magnetic domains were observed at all.

FIG. 6 shows a high-resolution cross-sectional transmission electron microscope (TEM) image of the magnetic recording medium of Example 1. C
It was found that the oBO layer and the PdBO layer were heteroepitaxially grown on the MgO (111) substrate and were (111) oriented. In the present invention, since the orientation is uniform over the entire surface, the distribution of the perpendicular anisotropy becomes uniform, and the switching domain is suppressed. On the other hand, a cross-sectional transmission electron microscope (TEM) image and an electron diffraction pattern of the magnetic recording medium of Comparative Example 1 are shown in FIG. Since the electron diffraction pattern was a ring pattern, it was found that the crystal orientation of each crystal grain was random. This random orientation causes dispersion of the perpendicular anisotropy, and as a result, locally generates a reversed magnetic domain.

Example 2 As a single crystal substrate, MgO
NiO or SrTiO ₃ instead of the (111) substrate
(111) oriented oxide single crystal substrate, made of Si (1
11) A magnetic recording medium according to the present invention was manufactured in exactly the same manner as in Example 1 using an oriented single crystal semiconductor substrate. As a result, the same effect as in the first embodiment was obtained also in such a magnetic recording medium.

[Embodiment 3] Instead of PdBO, Pd, Pt, Au, Pd,
Implemented using a base material containing a metal element having a face-centered cubic structure of Ag, Rh, and Ir, or a base material containing both B and O as a metal element having a face-centered cubic structure of Pt, Au, Ag, Rh, and Ir A magnetic recording medium according to the present invention was produced in exactly the same manner as in Example 1. As a result, the same effect as in Example 1 was obtained.

[0042]

According to the present invention, it is possible to obtain a magnetic recording medium having substantially no fine reversed magnetic domains and further improved high-frequency characteristics. Further, according to the present invention, the vertical squareness ratio is 1,
In addition, the transition region of the magnetic domain is clear, and as a result, a magnetic storage element that can stably maintain the magnetization of the minute region is obtained.

[Brief description of the drawings]

FIG. 1 is a fragmentary fragmentary view showing a layer structure in an embodiment of a magnetic recording medium or a magnetic storage element according to the present invention.

FIG. 2 is a fragmentary fragmentary view showing a layer structure in another embodiment of the magnetic recording medium or the magnetic storage element according to the present invention.

FIG. 3 is a fragmentary fragmentary view showing a layer structure in another embodiment of the magnetic recording medium or the magnetic storage element according to the present invention.

FIG. 4 is a plan view showing a sputtering target used in an example.

5A shows a magnetization curve of the perpendicular magnetic recording medium obtained in Comparative Example 1. FIG. (B) shows a magnetization curve of the perpendicular magnetic recording medium obtained in Example 1.

6 shows a high-resolution cross-sectional transmission electron microscope (TEM) image of the perpendicular magnetic recording medium obtained in Example 1. FIG.

7 shows a cross-sectional transmission electron microscope (TEM) image and an electron diffraction pattern of the magnetic recording medium obtained in Comparative Example 1. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic recording medium or magnetic storage element according to the present invention 2 Substrate 3 Adhesive layer 4 Underlayer 5 Perpendicular magnetization film 6 Protective layer 7 Soft magnetic layer 8 minute fault

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 11/105 526 G11B 11/105 526C H01F 10/16 H01F 10/16 F-term (Reference) 5D006 BB01 BB08 CA01 CB01 CB07 DA08 EA03 FA09 5D075 EE03 FF06 FF12 FG10 FG13 5E049 AA04 AC03 AC05 BA12 CB02 DB02 DB12

Claims (25)

[Claims] 1. (a) Pt layer or Pd containing B and O
A magnetic recording medium characterized in that a perpendicular magnetization film formed by alternately stacking layers and (b) Co layers containing B and O is formed on a single crystal substrate. 2. The magnetic recording medium according to claim 1, wherein the single crystal substrate is a cubic (111) oriented single crystal substrate. 3. A cubic (111) -oriented single crystal substrate,
3. The magnetic recording medium according to claim 2, wherein the medium is an oxide single crystal substrate. 4. The magnetic recording medium according to claim 3, wherein the oxide single crystal substrate is made of MgO, NiO, or SrTiO ₃ . 5. A cubic (111) -oriented single crystal substrate,
3. The magnetic recording medium according to claim 2, wherein the medium is a semiconductor single crystal substrate. 6. The magnetic recording medium according to claim 5, wherein the semiconductor single crystal substrate is made of Si. 7. An underlayer is formed on a single-crystal substrate, and a (a) Pt layer or Pd layer containing B and O and (b) a Co layer containing B and O are further formed thereon. A magnetic recording medium comprising perpendicular magnetic films alternately stacked. 8. The magnetic recording medium according to claim 7, wherein the single crystal substrate is a cubic (111) oriented single crystal substrate. 9. A cubic (111) -oriented single-crystal substrate,
9. The magnetic recording medium according to claim 8, wherein the medium is an oxide single crystal substrate or a semiconductor single crystal substrate. 10. The magnetic recording medium according to claim 7, wherein the underlayer is made of an underlayer material containing a metal element having a face-centered cubic structure. 11. The magnetic recording medium according to claim 10, wherein the base material further contains both B and O. 12. The metal element having a face-centered cubic structure is Pd, P
The magnetic recording medium according to claim 10, wherein the magnetic recording medium is t, Au, Pd, Ag, Rh, or Ir. 13. (a) Pt layer or P containing B and O
A magnetic memory element, wherein a perpendicular magnetization film in which a d layer and (b) a Co layer containing B and O are alternately stacked is formed on a single crystal substrate. 14. The magnetic memory element according to claim 13, wherein the single crystal substrate is a cubic (111) oriented single crystal substrate. 15. The cubic (111) -oriented single-crystal substrate is an oxide single-crystal substrate.
5. The magnetic storage element according to 4. 16. An oxide single crystal substrate comprising MgO, NiO
Or claim 1, characterized in that it consists of SrTiO ₃
6. The magnetic storage element according to 5. 17. The cubic (111) -oriented single crystal substrate is a semiconductor single crystal substrate.
5. The magnetic storage element according to 4. 18. The magnetic memory device according to claim 17, wherein the semiconductor single crystal substrate is made of Si. 19. A base layer is formed on a single-crystal substrate, and further, (a) a Pt layer or Pd layer containing B and O and (b) a Co layer containing B and O thereon. A magnetic memory element, wherein perpendicular magnetic films are alternately stacked. 20. The magnetic memory device according to claim 19, wherein the single crystal substrate is a cubic (111) oriented single crystal substrate. 21. The magnetic memory device according to claim 20, wherein the cubic (111) -oriented single crystal substrate is an oxide single crystal substrate or a semiconductor single crystal substrate. 22. The magnetic memory element according to claim 19, wherein the underlayer is made of an underlayer material containing a metal element having a face-centered cubic structure. 23. The magnetic memory element according to claim 22, wherein the base material further contains both B and O. 24. The metal element having a face-centered cubic structure is Pd, P
23. The magnetic storage element according to claim 22, wherein the element is t, Au, Pd, Ag, Rh, or Ir. 25. A magnetic recording medium according to claim 1, a holder for holding the magnetic recording medium,
A magnetic head for recording and reproducing information on and from the magnetic recording medium, a moving unit for moving a relative position between the magnetic head and the magnetic recording medium, and a control unit for controlling these units. Magnetic recording and reproducing apparatus.