KR100976013B1 - Magnetic recording and reproducing apparatus - Google Patents

Abstract

The present invention provides a magnetic recording and reproducing apparatus capable of reliably recording magnetic signals only in a recording area of a recording target of a magnetic recording medium having a high surface recording density, and the magnetic recording and reproducing apparatus 10 includes a track portion and a gap. At least a part of the portions corresponding to the track portions of the track patterns alternately arranged in the cross track direction are recording regions 22 having a width substantially equal to the width Tw of the track portions, and portions between the recording regions 22 are non-recorded. A recording area of the magnetic recording medium 12, comprising a vertical recording magnetic recording medium 12 which is an area 24 and a vertical magnetic recording head 12 for applying a recording magnetic field to the recording area 22; The anisotropic magnetic field of (22) is characterized by Hk (T) and the recording magnetic field strength of the recording magnetic field 14 on the upper surface of the recording area 22 as Fw (T).

(Equation 1)

Description

Magnetic recording and playback device {MAGNETIC RECORDING AND REPRODUCING APPARATUS}

The present invention provides a magnetic recording medium having a portion corresponding to the track portion or a portion thereof having a width substantially equal to the width of the track, and a portion between the recording regions being a non-recording region, and a magnetic head for recording data thereto. A magnetic recording and reproducing apparatus.

Background Art [0002] Conventionally, magnetic recording media such as hard disks have been remarkably improved by improving the material of the recording layer, miniaturizing head processing, and the like.

Further, a magnetic recording and reproducing apparatus having a vertical recording type magnetic recording medium for increasing surface recording density by orienting magnetic particles so as to be magnetized in a direction perpendicular to the surface, and a vertical recording type magnetic head for recording data thereto It is becoming.

In addition, a magnetic recording medium has been proposed in which a portion corresponding to the track portion or part thereof is a recording area having a width substantially equal to the width of the track, and a portion between the recording areas is a non-recording area.

For example, a discrete track medium in which the recording layer is formed with an uneven pattern corresponding to the track pattern, and the recording area which is the convex portion of the recording layer is in the shape of the track portion, or the shape where the recording area is the convex portion of the recording layer in the circumferential direction. Magnetic recording media, such as in-pattern media, are proposed (for example, Japanese Patent Laid-Open No. 2006-048860).

Further, for example, an ion implantation process or a treatment with a reaction gas is applied to a portion corresponding to either the recording area or the non-recording area of the recording layer, and the non-recording area and the saturation magnetization amount in which the saturation magnetization is substantially lost. A magnetic recording medium is also proposed, which is divided into a recording area having the same (see, for example, Japanese Unexamined Patent Publication No. 2006-286085 and Japanese Unexamined Patent Publication No. 2002-359138).

In this way, the presence of the non-recording area between the recording areas is expected to suppress erroneous information recording to another recording area in the neighborhood of the recording area to be recorded, crosstalk between adjacent recording areas, and the like. Such a technique is expected to further improve the surface recording density thereafter.

In a magnetic recording medium having a high surface recording density such as a vertical recording type, it is considered preferable to use a material having a large anisotropic magnetic field as the material of the recording area. By employing a material having a large anisotropic magnetic field as the material of the recording area, it is possible to suppress the recording of an erroneous magnetic signal to another recording area adjacent to the recording area of the recording object.

However, as the surface recording density of the magnetic recording medium increases, the width of magnetic poles of the magnetic head decreases, and the strength of the recording magnetic field applied to the magnetic recording medium tends to decrease. In this way, a material having a large anisotropic magnetic field is used as the material of the recording area, and in some cases, magnetic signals cannot be recorded in the recording area to be recorded because the strength of the recording magnetic field is reduced.

It is also possible, for example, to increase the strength of the recording magnetic field by increasing the magnetic pole width of the magnetic head. However, there is a case where a problem of incorrect magnetic signal recording to another recording area in the neighborhood of the recording area to be recorded occurs. there was.

SUMMARY OF THE INVENTION The present invention has been made in view of these problems, and an object thereof is to provide a magnetic recording and reproducing apparatus capable of reliably recording magnetic signals only in a recording area of a recording target of a magnetic recording medium having a high surface recording density.

In the process of reaching the present invention, the inventors performed a simulation by setting parameters related to the magnetic recording medium to various values. Therefore, in the case of a magnetic recording medium in which a portion corresponding to the track portion or a portion thereof is a recording area and a portion between the recording areas is a non-recording area, the inventors consider that even if the anisotropic magnetic field of the recording area is smaller than a conventional value, If the anisotropic magnetic field Hk of the recording area of the recording medium and the recording magnetic field strength Fw of the recording magnetic field on the upper surface of the recording area satisfy a predetermined relationship, the original magnetic signal can be recorded in the recording area of the recording object. It has also been found that the recording of a wrong magnetic signal can be suppressed to another recording area adjacent to the recording area to be recorded.

As described above, according to the present invention, in the case of a magnetic recording medium in which a portion corresponding to a track portion and a portion thereof is a recording area and a portion between the recording areas is a non-recording area, even if the surface recording density is high, the anisotropic magnetic field of the recording area is conventionally considered. It has been found that it can be made smaller, and the magnetic recording and reproducing apparatus which can reliably record the magnetic signal only in the recording area of the recording object is realized, and the surface recording density such as the vertical recording type is high (for example, 300Gbpsi). In the case of the above-described magnetic recording medium, a material having a large anisotropic magnetic field as the material of the recording layer is based on a concept different from the conventional art, which was common knowledge.

That is, the said object can be achieved by the following this invention.

(1) At least a portion of the track portion and the gap portion corresponding to the track portion of the track pattern alternately arranged in the cross track direction is a recording area having a width substantially equal to the width of the track portion, and the portions between the recording areas are non- And a vertical recording magnetic head for applying a recording magnetic field to the recording area, wherein the anisotropic magnetic field in the thickness direction of the recording area of the magnetic recording medium is Hk (T); A magnetic recording and reproducing apparatus according to claim 1, wherein the recording magnetic field strength of the recording magnetic field on the upper surface of the recording area is Fw (T).

(2) The magnetic recording and reproducing apparatus according to (1), wherein the recording magnetic field strength Fw (T) is 1.1 to 1.3 and satisfies the following expression (2).

(3) In (1), the magnetic field recording apparatus characterized in that the recording magnetic field strength Fw (T) is 1.3 to 1.6, and satisfies the following expression (3).

(4) At least a portion of the track portions and the gap portions corresponding to the track portions of the track pattern alternately arranged in the cross track direction are recording regions having a width substantially equal to the width of the track portions, and portions between the recording regions are non- A magnetic recording medium of a vertical recording type as a recording area, and a magnetic head of a vertical recording type for applying a recording magnetic field to the recording area, wherein an anisotropic magnetic field in the thickness direction of the recording area of the magnetic recording medium is Hk (T). And the recording magnetic field strength of the recording magnetic field on the upper surface of the recording area is Fw (T), and the anisotropic magnetic field Hk and the recording magnetic field strength Fw are represented by the following Equations 4, 5, 6, A magnetic recording and reproducing apparatus characterized by being limited to any one of Equations (7) and (8).

(5) In (4), the anisotropic magnetic field (Hk) and the recording magnetic field strength (Fw) is limited to any one of the following equations (9), (10), (11), (12) and (13) Magnetic recording and reproducing apparatus.

In addition, in this application, "a track pattern in which track parts and gap parts are arranged alternately in a cross track direction" includes a track pattern in which the track parts are concentric or arc-shaped, and a track pattern in which the track parts are spirally spiraled.

In addition, in this application, "a recording area in which at least part of the portions corresponding to the track portion has a width substantially equal to the width of the track portion" means that the entire track portion is a recording region and the recording region is in the shape of a track portion, and a portion of the track portion. Is a recording area and the recording area has a shape obtained by dividing the track portion in the circumferential direction. In addition, when the recording area has a shape in which the track portion is divided in the circumferential direction, not only the portion corresponding to the gap portion of the track pattern but also the portion between the recording regions divided into the circumference portion in the track portion is a non-recording region.

In the present application, the term "cross track direction" is used in the sense of a direction substantially parallel to the direction of the track width or the direction of the gap width.

In addition, in this application, the term "recording area" is used to mean a region having magnetizing reversal by applying a recording magnetic field and having the ability to keep the recorded magnetic signal reproducible.

In the present application, the term "non-recording area" is used in the sense that the ability to hold a magnetic signal is lower than that of the recording area, or a region that has substantially no ability to hold a magnetic signal so that it can be reproduced. More specifically, a non-recording area means that in a state where a magnetic signal is recorded on a magnetic recording medium, a magnetic field generated from the area is smaller than a magnetic field generated from the recording area, and there is substantially no magnetic field generated from the area. It means an area. In addition, the non-recording area may be configured to separate the recording area from the nonmagnetic material, or may be configured to separate the recording area into a material that is capable of disregarding magnetic influences or a magnetic material having a lower capacity than the recording area. It may be a void.

In addition, in the present application, the term "magnetic recording medium" is not limited to a hard disk, a floppy (registered trademark) disk, etc., which use only magnetism for recording and reproducing magnetic signals, and the like. It is used to include a magneto-optical recording medium and a thermal assist type recording medium that uses magnetism and heat together.

According to the present invention, it is possible to reliably record a magnetic signal only in a recording area of a recording target of a magnetic recording medium having a high surface recording density.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described in detail with reference to drawings.

As shown in Fig. 1, the magnetic recording and reproducing apparatus 10 according to the embodiment of the present invention records / reproduces a magnetic signal for the vertical recording type magnetic recording medium 12 and the magnetic recording medium 12. To this end, the magnetic recording medium 12 is provided with a vertical recording magnetic head 14 provided to be able to float near the surface of the magnetic recording medium 12.

In addition, the magnetic recording medium 12 has a center hole 12A, is fixed to the chuck 16 at the center hole 12A, and is free to rotate with the chuck 16. In addition, the magnetic head 14 is mounted near the tip of the arm 18, and the arm 18 is rotatably attached to the base 20. As a result, the magnetic head 14 is operated in an arc track along the cross track direction Dc (diameter direction) of the magnetic recording medium 12 in close proximity to the surface of the magnetic recording medium 12.

The magnetic recording medium 12 is a substantially disc-shaped discrete track media, and as shown in FIG. 2, a plurality of server areas SA set at appropriate intervals in the circumferential direction and a plurality of data partitioned into these server areas SA. It is divided into an area DA. The track pattern of the data area DA is a pattern in which concentric arc-shaped track portions having a predetermined track width Tw and gap portions having a predetermined gap width Gw are alternately arranged in the cross track direction Dc.

As shown in Figs. 3 and 4, the magnetic recording medium 12 corresponds to the track portion of the recording area 22, and the portion corresponding to the gap between the recording areas 22 represents the recording area 22. As shown in Figs. It is a non-recording area 24 for magnetic separation. Moreover, it is preferable that track width Tw is 30-60 nm. In addition, the gap width Gw is preferably 20 to 50 nm.

The magnetic recording and reproducing apparatus 10 records the anisotropic magnetic field of the recording area 22 of the magnetic recording medium 12 as Hk (T), and the recording magnetic strength on the upper surface of the recording area 22 of the recording magnetic field of the magnetic head 14. The following formula (1) is satisfied as Fw (T).

(Equation 1)

Other configurations are not considered to be important for the understanding of the present embodiment, and thus description thereof will be omitted as appropriate.

The magnetic recording medium 12 has a substrate 30, a soft magnetic layer 32, an alignment layer 34 and a recording layer 36, and these layers are formed on the substrate 30 in this order.

As the material of the substrate 30, nonmagnetic materials such as glass, Al alloy coated with NiP, Si, and Al ₂ O ₃ can be used.

The soft magnetic layer 32 is 50-300 nm in thickness. As the material of the soft magnetic layer 32, Fe alloy, Co amorphous alloy, ferrite, or the like can be used. In addition, the soft magnetic layer 32 may have a laminated structure of a soft magnetic layer and a nonmagnetic layer.

The alignment layer 34 has a thickness of 2 to 40 nm. As the material of the alignment layer 34, a nonmagnetic CoCr alloy, a laminate of Ti, Ru, Ru and Ta, MgO, and the like can be used.

The recording layer 36 is formed with an uneven pattern corresponding to the track pattern in the data area DA, and the recording element 36A, which is a convex portion of the uneven pattern, is the recording area 2. Specifically, the recording layer 36 is divided into a plurality of recording elements 36A, and the recording elements 36A are formed in the shape of the track portion in the data area DA. 3 and 4 illustrate this. The recording layer 36 is formed in a server pattern SA in a predetermined server pattern (not shown). The recording magnetic field strength Fw is the strength of the recording magnetic field of the magnetic head 14 on the upper surface of the recording element 36A.

The recording layer 36 has a thickness of 6 to 30 nm. The anisotropic magnetic field Hk in the thickness direction of the recording layer 36 is preferably 1.2 to 2.1T, more preferably 1.4T to 1.6T. As the material of the recording layer 36, an alloy containing Co and Cr, such as a CoCrPt alloy, an alloy containing Co and Pt, an alloy containing Co and Pd, an alloy containing Fe and Pt, an Fe and Co containing alloy, the ferromagnetic particles such as CoPt in the oxide materials such as those of the laminated body, SiO ₂ can be used in which the material or the like contained in a matrix. The recording layer 36 is oriented to magnetize in a direction perpendicular to the surface of the magnetic recording medium 12.

The side of the recording element 36A may also be tapered in a direction inclined toward the surface of the magnetic recording medium 12. In this case, the track width Tw and the gap width Gw are the widths at positions on the upper surface of the recording layer 36.

On the other hand, the filler 38 is filled in the recesses between the recording elements 36A corresponding to the gap portions. The filler 38 filling the recess portion constitutes the non-recording area 24. The material of the filler 38 is SiO ₂ , Al ₂ O ₃ , TiO ₂ , MgO, ZrO ₂ , oxides such as ferrite, nitrides such as AlN, carbides such as SiC, DLC (diamond like carbon), Cu or Cr A nonmagnetic metal, resin material, etc. can be used. The upper surface of the recording element 36A and the filler material 38 is almost flat.

In addition, although the protective layer and the lubricating layer may be formed in this order on the recording layer 36 and the filler 38, since these layers are not considered important for understanding of this embodiment, illustration and description are abbreviate | omitted here. .

In addition, although a base layer or an antiferromagnetic layer may be formed between the board | substrate 30 and the soft magnetic layer 32, since these layers are also not considered important for understanding this embodiment, illustration and description are abbreviate | omitted here. .

The magnetic head 14 has a recording head portion 40 and a reproduction head portion 42 as shown in FIG.

The recording head portion 40 has a main magnetic pole 26 for applying a recording magnetic field to the recording area 22 and a magnetic head 14 relative to the drive of the magnetic recording medium 12 in front of the main magnetic pole 26. The auxiliary magnetic pole 44 provided on the front side in the advancing direction) and the rear side of the main magnetic pole 26 (the rear side in the advancing direction of the magnetic head 14 relative to the driving of the magnetic recording medium 12). The provided trailing shield 26 and the excitation coil 48 are provided. In addition, the arrow in the right direction in FIG. 5 and the arrow in the upper direction in FIG. 3 indicate the advancing direction of the magnetic recording medium 12.

The reproduction head section 42 is provided on the front side of the recording head section 40. The playhead section 42 includes an MR element 50, a leading shield 52 provided on the front side of the MR element 50, and an intermediate shield provided between the MR element 50 and the auxiliary magnetic pole 44. 54).

The main magnetic pole 26 has a shape in which the leading end closer to the magnetic recording medium 12 is narrower than the proximal end in the circumferential direction of the track portion. It is preferable that the main magnetic pole width Pw of the leading cross track direction Dc of the main magnetic pole 26 is 30-60 nm. Materials of the main magnetic pole 26 include alloys containing Co, alloys containing Fe, alloys containing Fe and Co, alloys containing Fe and Ni, alloys containing Fe and N, containing Fe and Al Soft magnetic materials such as alloys can be used. The magnetic gap between the lower surface of the main magnetic pole 26 and the upper surface of the recording layer 36 is preferably 6 to 15 nm.

3 shows a cross section near the tip of the main magnetic pole 26 with respect to the magnetic head 14, and schematically illustrates the external shape of the main magnetic pole 26 viewed from the direction perpendicular to the surface of the magnetic recording medium 12. As shown in FIG. It is shown as an enemy. In addition, hatching of the magnetic recording medium 12 in FIG. 3 is for distinguishing between the recording area 22 and the non-recording area 24, and does not show a cross section. 3, the shape of the tip of the main magnetic pole 26 as seen from the direction perpendicular to the surface of the magnetic recording medium 12 is rectangular, but the shape of the tip of the main magnetic pole 26 is greater than that of the front side. It may be long nearly trapezoidal. In this case, the above-described main magnetic pole width Pw (width of the tip of the main magnetic pole 26) is the maximum width (length of the long side on the rear side).

The MR element 50 is a TMR element, a GMR element, or the like. It is preferable that the reproduction head width Rw in the crosstrack direction Dc at the tip of the MR element 50 is 20 to 60 nm.

Next, the operation of the magnetic recording and reproducing apparatus 10 will be described.

The magnetic recording and reproducing apparatus 10 includes an anisotropic magnetic field Hk (T) of the recording area 22 of the magnetic recording medium 12 and a recording magnetic field of the recording magnetic field of the magnetic head 14 on the upper surface of the recording area 22. The intensity Fw (T) satisfies the above expression (1).

Therefore, even if the anisotropic magnetic field of the recording area 22 (Hk (anisotropic magnetic field of the recording layer 36)) is smaller than that previously assumed, the original magnetic signal can be recorded in the recording area 22 to be recorded. In addition, it is possible to suppress the recording of an erroneous magnetic signal in another recording area 22 adjacent to the recording area 22 as the recording object.

If the recording magnetic field strength Fw (T) is 1.3 or less, the original magnetic signal is recorded in the recording area 22 of the recording object, and the recording magnetic field 22 is recorded in another recording area 22 adjacent to the recording area 22 of the recording object. In order to increase the effect of suppressing the recording of the wrong magnetic signal, it is preferable that the anisotropic magnetic field Hk (T) and the recording magnetic field strength Fw (T) satisfy the following expression (2).

(Equation 2)

When the recording magnetic field strength Fw (T) is 1.3 or more, the original magnetic signal is recorded in the recording area 22 of the recording object, and the other recording area 22 adjacent to the recording area 22 of the recording object is recorded. It is preferable that the anisotropic magnetic field Hk (T) and the recording magnetic field strength Fw (T) satisfy the following expression (3) in order to increase the effect of suppressing the recording of the wrong magnetic signal in the < RTI ID = 0.0 >

(Equation 3)

The basis of Equation 1, Equation 2, and Equation 3 will be described later in detail in the column of Simulation Example described later.

The anisotropic magnetic field Hk and the recording magnetic field strength Fw may be limited to any one of the following equations (4), (5), (6), (7) and (8).

(Equation 4)

(5)

(6)

(Equation 7)

(Equation 8)

By doing in this way, the anisotropic magnetic field Hk of the recording area 22 (recording layer (A) is the same as when the anisotropic magnetic field Hk (T) and the recording magnetic field strength Fw (T) satisfy the above expression (1). Even if the anisotropic magnetic field of 36) is smaller than a previously assumed value, the original magnetic signal can be recorded in the recording area 22 of the recording object, and the other neighboring regions of the recording area 22 of the recording object can be recorded. Recording of a wrong magnetic signal into the recording area 22 can be suppressed.

The anisotropic magnetic field Hk and the recording magnetic field strength Fw may be limited to any one of the following formulas (9), (10), (11), (12) and (13).

(Equation 9)

(Equation 10)

(Equation 11)

(Equation 12)

(Equation 13)

By doing in this way, the anisotropic magnetic field Hk (T) and the recording magnetic field strength Fw (T) are intrinsic to the recording area 22 to be recorded, similarly to the case where the equations (2) and (3) are satisfied. The magnetic signal can be recorded, and the effect of suppressing the recording of the wrong magnetic signal in another recording area 22 adjacent to the recording area 22 as the recording object can be enhanced.

The basis of the ranges of the equations (4) to (13) will also be described in detail in the section of the simulation example described later.

In the above embodiment, as the material of the filler 38, oxides such as SiO ₂ , Al ₂ O ₃ , TiO ₂ , MgO, ZrO ₂ , ferrite, nitrides such as AlN, carbides such as SiC, DLC, Cu, Cr and Although the same non-magnetic metal, resin material, and the like are exemplified, as long as the material is chemically stable and the material capable of holding a magnetic signal is substantially lower than the recording area, or has a material substantially not capable of maintaining a magnetic signal to be reproducible, a filler ( The material of 38) is not specifically limited. For example, as the material of the filler 38, a magnetic material having a lower capacity than the recording area may be used so that other nonmagnetic materials and magnetic influences can be ignored.

In the above embodiment, the filler 38 is provided in the non-recording area 24, but the ion implantation process or the reaction gas is applied to a portion corresponding to either the recording area or the non-recording area of the recording layer. Thus, a non-recording area in which the saturation magnetization is substantially lost and a recording area having a saturation magnetization amount may be formed.

In addition, in the above embodiment, the magnetic recording medium 12 is provided with a filler 38 in the non-recording area 24 so that the surface thereof is almost flat, but the surface of the magnetic recording medium 12 has an uneven pattern of the recording layer 36. Alternatively, even in the case of the uneven pattern imitating this, when the stable head floating height is obtained, the non-recording area 24 may be a concave portion without providing the filler 38 in the non-recording area 24.

Further, in the above embodiment, the magnetic recording medium 12 is a single-sided recording type in which a recording layer 36 is formed on one side of the substrate 30, but a double-sided recording type magnetic recording medium in which a recording layer is formed on both sides of the substrate. The present invention can also be applied.

Further, in the above embodiment, the magnetic recording medium 12 is a discrete track media in which the recording area 22 is in the shape of a track part. However, the present invention also relates to a patterned media in which the recording area 22 is divided into track parts in the circumferential direction. Is applicable.

Further, in the above embodiment, the track pattern of the magnetic recording medium 12 is a pattern in which the track portion is a concentric circular arc shape, but the present invention is also applicable to the magnetic recording medium of the track pattern in which the track portion is a spiral shape.

In addition, in the above embodiment, the recording layer 36 is divided into a plurality of recording elements 36A. However, as shown in FIG. 6, the lower surface of the substrate 60 side is continuous and the upper surface of the non-recording area 24 is shown. A magnetic recording medium 64 having a recording layer 62 of a concave-convex pattern recessed on the side of the substrate 60 rather than an upper surface of the recording area 22, as shown in FIG. 7, of the concave-convex pattern of the substrate 70. Magnetic recording medium 74 having a continuous recording layer 72 formed by imitating the surface, recording formed by dividing the upper surface of the convex portion and the upper surface of the concave portion of the surface of the uneven pattern of the substrate 80 as shown in FIG. The present invention is also applicable to the magnetic recording medium 84 having the layer 82. 6 to 8, the recording magnetic field strength Fw is the intensity of the recording magnetic field of the magnetic head 14 on the upper surface of the portion of the recording layers 62, 72, and 82 disposed in the recording area 22. In addition, in FIG. to be.

Simulation Example A

Six types of simulation models A1 and A2 in which the track width Tw, the gap width Gw, the main stimulus width Pw, and the reproduction head width Rw in the above embodiment are set to the values shown in the example of Table A. , A3, A4, A5 and A6 were created.

In addition, the values of the recording magnetic field strengths Fw (T) of the recording magnetic field of the magnetic head 14 on the upper surface of the recording area 22 were set to different values with respect to these simulation models A1 to A6. Specifically, for the simulation models A1, A2, A3, A4, A5, and A6, the recording magnetic field strengths Fw (T) were set to 1.1T, 1.2T, 1.3T, 1.4T, 1.5T, and 1.6T, respectively. .

The anisotropic magnetic field Hk (T) of the recording area 22 of the magnetic recording medium 12 (the anisotropic magnetic field Hk of the recording layer 36) is 1.2 to 2.1T for each simulation model A1 to A6. A simulation was performed in which magnetic signals were recorded in the recording area 22 to be recorded in the recording magnetic field set by a plurality of values at intervals of 0.1T in the range and the main magnetic pole 26 was emitted. The simulation of this recording process was performed by the Landau-Lifishts-Gilbert (LLG) equation.

In addition, the center of the cross track direction Dc of the main magnetic pole 26 was set so that the recording object may be located just above the center of the cross track direction Dc of the recording area 22. The value of the recording magnetic field strength Fw (T) is a value at the center of the cross track direction Dc of the upper surface of the recording area 22 to be recorded.

Other conditions were set as follows. These conditions are common to the simulation models A1 to A6.

Thickness of the recording layer 36: 8 nm

Saturation magnetization amount of the recording layer 36: 1.0T

Thickness of the soft magnetic layer 32: 80 nm

Saturation magnetization of the soft magnetic layer 32: 1.5T

Saturation magnetization of the main stimulus 26: 2.3T

Length Pt of the main magnetic pole 26 in the circumferential direction of the medium: 140 nm

Magnetic gap between the main pole 26 and the recording area 22: 10 nm

Exchange constant between particles constituting the recording layer 36: 1 × 10 ⁻⁷ erg / cm

Anisotropic dispersion (dispersion range of easy magnetization axis of recording layer 36): ± 5 °

In addition, a simulation was performed to reproduce the magnetic signal from the recording area 22 to be recorded, and the S / N ratio (dB) was calculated.

In addition, the center of the cross track direction Dc of the MR element 50 was also set to be located directly above the center of the cross track direction Dc of the recording area 22 to be recorded. In addition, the magnetic gap between the MR element 50 and the recording area 22 was set to 10 nm. In addition, the simulation of the regeneration process was performed using the Lindholm distribution function as a sensitivity function of the MR element 50.

Table 2 and FIGS. 9 to 14 show calculation results of the S / N ratios of the reproduction signals of the simulation models A1 to A6. In addition, the value of the S / N ratio shown in Table 2 and FIGS. 9-14 is the simulation model B6 of simulation example B in which the absolute value of S / N ratio was the largest among this simulation example A and the simulation examples B and C mentioned later. The maximum value of the absolute value of the S / N ratio (the value of the S / N ratio when Hk = 1.8T in the simulation model B6) is normalized as 0.0 dB. It is the same about Table 5 of FIG. 5 and FIG. 17-FIG. 22 of Simulation Example B mentioned later, and Table 8 of FIG.

As shown in Table 2 and FIGS. 9 to 14, for any of the simulation models A1 to A6, the anisotropic magnetic field Hk (T) of the recording area 22 of the magnetic recording medium 12 is set at a predetermined value. The S / N ratio was maximum, and even if the anisotropic magnetic field (Hk (T)) was smaller than this, the S / N ratio tended to be small.

When the anisotropic magnetic field Hk (T) of the recording area 22 is small, the S / N ratio is reduced because the magnetic signal is accidentally recorded in another neighboring recording area 22 of the recording area 22 to be recorded. I think. On the other hand, when the anisotropic magnetic field Hk (T) of the recording area 22 is large, it is considered that the recording of the original magnetic signal to the recording area 22 to be recorded is incomplete, resulting in a small S / N ratio.

Moreover, when the anisotropic magnetic field Hk (T) became smaller than the predetermined lower boundary value or larger than the predetermined upper boundary value, the S / N ratio tended to decrease rapidly. The relationship between the value of the recording magnetic field strength Fw (T) of each simulation model and the value of the anisotropic magnetic field Hk (T) of the recording area 22, which is the boundary between the lower side and the upper side, where the S / N ratio decreases rapidly. 3 and FIG. 15.

In addition, the anisotropic magnetic field of the recording area 22, which is a boundary between the lower and upper sides of the value of the recording magnetic field strength Fw (T) of each simulation model and the S / N ratio is smaller than the maximum value of or close to the value of each simulation model ( Table 4 and Table 16 show the relationship between the values of Hk (T)).

Simulation Example B

For the simulation example A, six types of simulation models B1 in which the track width Tw, the gap width Gw, the main magnetic pole width Pw, and the reproduction head width Rw are set to the values shown in column B of Table 1, B2, B3, B4, B5 and B6 were created. For these simulation models B1, B2, B3, B4, B5 and B6, the recording magnetic field strengths Fw (T) were respectively 1.1T, 1.2T, 1.3T, 1.4T, 1.5T, It set to 1.6 T. The other conditions were set on the same conditions as simulation example A. FIG.

In addition, the anisotropic magnetic field Hk (T) of the recording area 22 of the magnetic recording medium 12 also has a 0.1T interval in the range of 1.2 to 2.1T for each simulation model B1 to B6, similarly to the simulation example A. A plurality of values were set and a simulation was performed in which magnetic signals were recorded in the recording area 22 of the recording object in the recording magnetic field generated by the main magnetic pole 26.

In addition, as in the simulation example A, a simulation of reproducing the magnetic signal from the recording area 22 to be recorded was performed, and the S / N ratio (dB) was calculated.

Table 5 and FIGS. 17 to 22 show the results of calculating the S / N ratios of the reproduction signals of the simulation models B1 to B6.

In the same manner as in Simulation Example A, in any of the simulation models B1 to B6, the anisotropic magnetic field Hk (T) of the recording area 22 of the magnetic recording medium 12 is set to a predetermined value and the S / N ratio is maximized. Even if the anisotropic magnetic field Hk (T) is smaller than this, the S / N ratio tends to be small.

Moreover, when the anisotropic magnetic field Hk (T) became smaller than the predetermined lower boundary value or larger than the predetermined upper boundary value, the S / N ratio tended to decrease rapidly. The relationship between the value of the recording magnetic field strength Fw (T) of the simulation model and the value of the anisotropic magnetic field Hk (T) of the recording area 22, which is the boundary between the lower and upper sides where the S / N ratio is sharply reduced. 6 and FIG. 23.

In addition, the anisotropic magnetic field of the recording area 22, which is a boundary between the lower and upper sides of the value of the recording magnetic field strength Fw (T) of each simulation model and the S / N ratio is smaller than the maximum value of or close to the value of each simulation model ( The relationship between the values of Hk (T)) is shown in Table 7 and FIG. 24.

Simulation Example C

Six simulation models C1, C2, and C, in which the track width Tw, the gap width Gw, the main stimulus width Pw, and the playhead width Rw are set to values shown in column C of Table 1 with respect to the simulation example A. C3, C4, C5 and C6 were created. For these simulation models C1, C2, C3, C4, C5 and C6, the recording magnetic field strengths (Fw (T)) were respectively 1.1T, 1.2T, 1.3T, 1.4T, 1.5T, Set to 1.6T. Other conditions were set under the same conditions as in Simulation Example A.

In addition, the anisotropic magnetic field (Hk (T)) of the recording area 22 of the magnetic recording medium 12 is also 0.1T interval in the range of 1.2 to 2.1T with respect to each simulation model C1 to C6, similarly to the simulation example A. A plurality of values were set, and a simulation was performed in which magnetic signals were recorded in the recording area 22 to be recorded in the recording magnetic field generated by the main magnetic pole 26.

In addition, as in the simulation example A, the simulation of reproducing the magnetic signal from the recording area 22 as the recording object was performed, and the S / N ratio (dB) was calculated.

The calculation results of the S / N ratios of the simulation models C1 to C6 are shown in Table 8 and FIGS. 25 to 30.

In the same manner as in Simulation Example A, in any of the simulation models C1 to C6, the anisotropic magnetic field Hk (T) of the recording area 22 of the magnetic recording medium 12 has a predetermined value and the S / N ratio is maximized. Even if the anisotropic magnetic field Hk (T) was smaller than this, the S / N ratio tended to be small.

Moreover, when the anisotropic magnetic field Hk (T) became smaller than the predetermined lower boundary value or larger than the predetermined upper boundary value, the S / N ratio tended to decrease rapidly. The relationship between the value of the recording magnetic field strength Fw (T) of each simulation model and the value of the anisotropic magnetic field Hk (T) of the recording area 22, which is the boundary between the lower side and the upper side, where the S / N ratio decreases rapidly. 9 and FIG. 31.

In addition, the anisotropic magnetic field of the recording area 22, which is a boundary between the lower and upper sides of the value of the recording magnetic field strength Fw (T) of each simulation model and the S / N ratio is smaller than the maximum value of or close to the value of each simulation model ( Table 10 and FIG. 32 show the relationship between the values of Hk (T)).

As shown in FIG. 15, FIG. 23, and FIG. 31, in any of simulation examples A, B, and C, the S / N ratio decreases rapidly with respect to the increase or decrease of the value of the recording magnetic field strength Fw (T) of each simulation model. The value of the anisotropic magnetic field Hk (T) of the recording area 22, which is the lower boundary, tends to increase or decrease linearly. In addition, the value of the anisotropic magnetic field Hk (T) of the recording area 22, which is an upper boundary where the S / N ratio decreases rapidly, also increases or decreases the value of the recording magnetic field strength Fw (T) of each simulation model. There was a tendency to increase or decrease primarily. In addition, the upper boundary almost coincided with simulation examples A, B, and C. FIG. On the other hand, the boundary on the lower limit side was almost identical in Simulation Examples B and C, but in Simulation Example A, it was slightly different from Simulation Examples B and C.

The area between the straight line approximating the lower boundary and the straight line approximating the upper boundary, and the overlapping regions in FIGS. 15, 23, and 31 for Simulation Examples A, B, and C are shown in FIG. It was an area between a straight line approximating the boundary on the lower limit side and a straight line approximating the boundary on the upper limit side.

As shown in Table 1, in the simulation example A, the track width Tw and the gap width Gw are smaller than the simulation examples B and C, and the main stimulus width Pw and the reproduction head width Rw are the simulation examples B, Since it is wider than C, it is thought that the noise resulting from the reproduction magnetic field of the neighboring recording area 22 of the recording area 22 to be recorded is increased, which is the result. Thus, the value of the recording magnetic field strength Fw (T) and the anisotropic magnetic field Hk (in the region between the straight line approximating the lower boundary of FIG. 15 and the straight line approximating the upper boundary) of the simulation example A with the most severe conditions. By limiting the value of T)), the S / N ratio of a value larger than the S / N ratio of the rapidly decreasing range is surely obtained.

The straight line which approximated the boundary of the lower limit side of FIG. 15 concerning Simulation Example A is as follows.

In addition, the straight line which approximated the boundary of an upper limit side is as follows.

Accordingly, the anisotropic magnetic field Hk (T) of the recording area 22 of the magnetic recording medium 12 and the recording magnetic field strength Fw (T) of the recording head 14 on the upper surface of the recording area 22 are the above. When the expression (1) is satisfied, the S / N ratio of a value larger than the S / N ratio in the rapidly decreasing range is surely obtained.

In addition, in FIG. 15 regarding the simulation example A, the anisotropic magnetic field Hk and the recording magnetic field strength Fw are expressed by the following equation by focusing on five regions of 0.1 (T) intervals of 1.1 to 1.6 with the recording magnetic field strength Fw. Similarly, even when limited to the ranges of 4, 5, 6, and 8, an S / N ratio of a value larger than the S / N ratio of a rapidly decreasing range can be reliably obtained.

(Equation 4)

(5)

(6)

(Equation 7)

(Equation 8)

As shown in Figs. 16, 24, and 32, in any of the simulation examples A, B, and C, S / N with respect to the increase or decrease of the value of the recording magnetic field strength Fw (T) of each simulation model. The value of the anisotropic magnetic field Hk (T) of the recording area 22, whose ratio is lower than the maximum value of each simulation model or a value close thereto, tended to increase or decrease linearly. In addition, the magnetic field strength Fw of the recording field 22, which is the upper boundary where the S / N ratio becomes smaller than the maximum value or the value close to each simulation model, is 1.2T or more. Further, in the range of 1.3T or less, there was a tendency to increase or decrease with respect to the increase or decrease of the value of the recording magnetic field strength Fw (T) of each simulation model. The value of the anisotropic magnetic field Hk (T) of the recording area 22, which is the upper boundary where the S / N ratio becomes smaller than the maximum value or the value close to each simulation model, has a recording magnetic field strength Fw of 1.2T or less. In the range of and over 1.3T was almost constant. In addition, although the boundary of an upper side and the boundary of a lower limit were substantially identical in simulation examples B and C, in simulation example A, it was different from simulation examples B and C.

The area between the straight line approximating the lower boundary and the straight line approximating the upper boundary is the region overlapping in FIGS. 16, 24, and 32 for Simulation Examples A, B, and C. It was an area | region between the straight line which approximated the boundary of a lower limit, and the straight line which approximated the boundary of an upper limit.

The straight line which approximated the boundary of the lower limit side of FIG. 16 concerning simulation example A is as follows.

In addition, the straight line approximating the boundary on the upper limit side has the following formula in the range where the recording magnetic field strength Fw is 1.3T or less.

In addition, in the range where the recording magnetic field strength Fw is 1.3T or more, the following equation is obtained.

Accordingly, the anisotropic magnetic field Hk (T) of the recording area 22 of the magnetic recording medium 12 and the recording magnetic field strength Fw (T) of the recording head 14 on the upper surface of the recording area 22 are the above. When Equations 2 and 3 are satisfied, the S / N ratio of the maximum value or the value close thereto is surely obtained.

In addition, the recording magnetic field strength Fw in FIG. 16 according to the simulation example A focuses on five regions at intervals of 0.1 (T) of 1.1 to 1.6, followed by anisotropic magnetic field Hk and recording magnetic field strength Fw. The same applies to the limits of the formulas (9), (10), (11), (12) and (13), and the S / N ratio of the maximum value or the value close thereto is surely obtained.

(Equation 9)

(Equation 10)

(Equation 11)

(Equation 12)

(Equation 13)

In addition, in the simulation examples A to C, the values of the thickness of the recording layer 36, the magnetic gaps of the main magnetic poles 26 and the recording region 22, and the magnetic gaps of the MR elements 50 and the recording region 22 are determined. Even if it varies, the S / N ratio of the reproduction signal hardly changes. For example, the thickness of the recording layer 36 is 6-30 nm, the magnetic gap of the main magnetic pole 26 and the recording area 22 is 6-15 nm, and the MR element 50 and the recording area 22 are formed. If the values of the magnetic gaps are in the range of 6 to 15 nm, even if these values fluctuate, the values of the S / N ratios of the reproduction signals of the respective simulation models hardly fluctuate.

Finally, an example of a measuring method of the recording magnetic field strength Fw will be described. First, the relationship between the magnitude of the recording current energized by the recording head portion to generate the recording magnetic field in the recording head portion and the output by the reproduction magnetic field generated by the recording layer magnetized at the recording current of that magnitude are obtained. Specifically, in a state in which the recording layer of the magnetic recording medium is magnetically alternatingly erased, a recording current having a sufficiently small value is supplied to the recording head portion to apply a recording magnetic field to the recording layer to magnetize the recording layer. At this time, it is preferable to magnetize the recording layer so that recording bits having the same polarity (magnetization direction) are continuous in the circumferential direction by 200 nm or more in the recording area of the recording layer. For example, when the shortest recording bit length 1T is 20 nm, it is preferable to record a signal of 10T or more in the recording layer. Then, the reproducing magnetic field generated by the magnetized recording layer is detected by the reproducing head section, and the output by the reproducing magnetic field is measured. As the output by the reproducing magnetic field, for example, a potential difference generated in the MR element of the reproducing head portion by the regenerating magnetic field or a value obtained by amplifying the potential difference at a constant ratio may be measured. In addition, the same measurement is repeated while increasing the magnitude of the write current little by little. Since the recording magnetic field strength Fw is proportional to the magnitude of the recording current, the magnetization of the recording layer increases with increasing magnitude of the recording current until the recording layer is magnetically saturated, as shown in FIG. In addition, the output by the reproducing magnetic field emitted by the recording layer also increases. On the other hand, when the magnitude of the recording current is greater than or equal to a predetermined value and the recording layer is magnetically saturated, the output by the reproducing magnetic field emitted by the recording layer becomes constant regardless of the magnitude of the recording current. In Fig. 33, Iw on the horizontal axis represents the magnitude of the write current, and Iws represents the lower limit of the write current that magnetically saturates the recording layer. In addition, Vout of the horizontal axis represents the potential difference which arises in a reproduction head part by a regeneration magnetic field, or the value which amplified the said potential difference by a fixed ratio.

Next, the saturation magnetic field Hs of the recording layer of the magnetic recording medium is measured. The saturation magnetic field Hs is a lower limit value of the external magnetic field that magnetically saturates the magnetic material constituting the recording layer in the hysteresis loop obtained by applying an external magnetic field to the magnetic material constituting the recording layer. The saturation magnetic field Hs of the recording layer provided in the magnetic recording medium can be measured using, for example, a magnetic Kerr effect.

As described above, the recording magnetic field strength Fw is proportional to the magnitude of the recording current. In addition, when the magnitude of the recording current is Iws, it is assumed that a recording magnetic field having a magnitude of Hs is applied to the recording layer of the magnetic recording medium. Therefore, the recording magnetic field strength Fw can be calculated by the following equation based on Iw, Iws and Hs.

In addition, in order to measure the relationship between the magnitude Iw of the recording current and the magnitude Vout of the output by the reproducing magnetic field, it is necessary to adjust the magnitude of the recording current passing through the recording head portion as described above. On the other hand, in the general magnetic recording and reproducing apparatus, the magnitude of the recording current is kept constant, and the magnitude of the recording current cannot be adjusted. In such a case, the magnetic head and the magnetic recording medium are separated from the magnetic recording and reproducing apparatus, and the magnetic head and the magnetic recording medium are separated by a measuring device that can adjust the magnitude of the recording current passing through the recording head. What is necessary is to measure the relationship between magnitude (Iw) and Vout with a large output by the reproducing magnetic field.

(Industrial availability)

The present invention can be used in a magnetic recording / reproducing apparatus having a magnetic recording medium in which a portion corresponding to the track portion or a portion thereof has a width substantially equal to the width of the track portion, and a portion between the recording regions is a non-recording region.

1 is a perspective view schematically showing a schematic structure of a magnetic recording and reproducing apparatus according to an embodiment of the present invention;

2 is a plan view schematically showing a schematic structure of a magnetic recording medium of the magnetic recording and reproducing apparatus according to the embodiment of the present invention;

3 is a plan view schematically showing an enlarged structure of a magnetic head and a magnetic recording medium of the magnetic recording and reproducing apparatus according to the embodiment of the present invention;

4 is a cross-sectional view along a cross track direction schematically showing an enlarged structure of a magnetic head and a magnetic recording medium of the magnetic recording and reproducing apparatus according to the embodiment of the present invention;

Fig. 5 is a sectional view along a circumferential direction of a track section schematically showing an enlarged structure of a magnetic head and a magnetic recording medium of the magnetic recording and reproducing apparatus according to the embodiment of the present invention;

6 is a cross-sectional view along the cross track direction schematically showing another example of the structure of the magnetic recording medium according to the embodiment of the present invention;

7 is a sectional view along a cross track direction schematically showing another example of the structure of the magnetic recording medium according to the embodiment of the present invention;

8 is a sectional view along a cross track direction schematically showing another example of the structure of the magnetic recording medium according to the embodiment of the present invention;

9 is a graph showing a relationship between anisotropic magnetic field and S / N ratio in a recording area according to simulation model A1;

10 is a graph showing a relationship between anisotropic magnetic field and S / N ratio in a recording area according to simulation model A2;

11 is a graph showing the relationship between anisotropic magnetic field and S / N ratio in a recording area according to simulation model A3;

12 is a graph showing a relationship between anisotropic magnetic field and S / N ratio in a recording area according to simulation model A4;

13 is a graph showing a relationship between anisotropic magnetic field and S / N ratio in a recording area according to simulation model A5;

14 is a graph showing a relationship between anisotropic magnetic field and S / N ratio in a recording area according to simulation model A6;

FIG. 15 is a graph showing the relationship between the value of the recording magnetic field strength and the value of the anisotropic magnetic field of the recording area which is a boundary at which the S / N ratio is sharply reduced in Simulation Example A;

FIG. 16 is a graph showing the relationship between the value of the recording magnetic field strength and the value of the anisotropic magnetic field of the recording area which is the boundary at which the S / N ratio is smaller than the maximum value or the value close to the simulation example A;

17 is a graph showing a relationship between anisotropic magnetic field and S / N ratio in a recording area according to simulation model B1;

18 is a graph showing the relationship between anisotropic magnetic field and S / N ratio in the recording area for simulation model B2;

19 is a graph showing a relationship between anisotropic magnetic field and S / N ratio in a recording area according to simulation model B3;

20 is a graph showing a relationship between anisotropic magnetic field and S / N ratio of a recording area according to simulation model B4;

21 is a graph showing the relationship between the anisotropic magnetic field and the S / N ratio of the recording area for simulation model B5;

22 is a graph showing the relationship between the anisotropic magnetic field and the S / N ratio of the recording area for simulation model B6;

23 is a graph showing the relationship between the value of the recording magnetic field strength and the value of the anisotropic magnetic field of the recording area which is a boundary at which the S / N ratio is sharply reduced in Simulation Example B;

24 is a graph showing the relationship between the value of the recording magnetic field strength and the value of the anisotropic magnetic field of the recording area which is the boundary at which the S / N ratio is smaller than the maximum value or the value close to the simulation example B;

25 is a graph showing a relationship between anisotropic magnetic field and S / N ratio in a recording area according to simulation model C1;

26 is a graph showing the relationship between the anisotropic magnetic field and the S / N ratio of the recording area in simulation model C2;

27 is a graph showing the relationship between the anisotropic magnetic field and the S / N ratio of the recording area according to the simulation model C3;

28 is a graph showing the relationship between anisotropic magnetic field and S / N ratio in the recording area according to simulation model C4;

29 is a graph showing the relationship between the anisotropic magnetic field and the S / N ratio of the recording area according to the simulation model C5;

30 is a graph showing the relationship between the anisotropic magnetic field and the S / N ratio of the recording area in simulation model C6;

Fig. 31 is a graph showing the relationship between the value of the recording magnetic field strength and the value of the anisotropic magnetic field of the recording area which is the boundary at which the S / N ratio is sharply reduced in Simulation Example C;

32 is a graph showing the relationship between the value of the recording magnetic field strength and the value of the anisotropic magnetic field of the recording area which is the boundary at which the S / N ratio is smaller than the maximum value or the value close to the simulation example C;

33 is a graph schematically showing the relationship between the magnitude of the recording current and the output of the reproduction magnetic field emitted by the recording layer.

* Explanation of symbols for the main parts of the drawings

10: magnetic recording and reproducing apparatus 12: magnetic recording medium

12A: center hole 14: magnetic head

16: chuck 18: cancer

22: recording area 30: substrate

32: soft magnetic layer 34: alignment layer

36: recording layer 40: recording head portion

42: playhead 44: auxiliary stimulation

Claims (5)

Vertical recording in which at least a portion of the track portion and the gap portion corresponding to the track portion of the track pattern alternately arranged in the cross track direction is a recording area having a width equal to the width of the track portion, and a portion between the recording areas is a non-recording area. And a vertical recording magnetic head for applying a recording magnetic field to the recording area, wherein anisotropic magnetic field in the thickness direction of the recording area of the magnetic recording medium is Hk (T), and an upper surface of the recording area. A magnetic recording and reproducing apparatus according to Equation 1, wherein the recording magnetic field strength of the recording magnetic field is < RTI ID = 0.0 > Fw (T). ≪ / RTI > (Equation 1)

The method of claim 1, And the recording magnetic field strength Fw (T) is 1.1 ≦ Fw ≦ 1.3, and satisfies the following expression (2). (Equation 2)

The method of claim 1, And the recording magnetic field strength Fw (T) is 1.3 ≦ Fw ≦ 1.6, and satisfies the following expression (3). (Equation 3)

Vertical recording in which at least a portion of the track portion and the gap portion corresponding to the track portion of the track pattern alternately arranged in the cross track direction is a recording area having a width equal to the width of the track portion, and a portion between the recording areas is a non-recording area. A magnetic recording medium having a vertical recording type magnetic head for applying a recording magnetic field to the recording area, wherein anisotropic magnetic field in the thickness direction of the recording area of the magnetic recording medium is Hk (T); The recording magnetic field strength of the recording magnetic field on the upper surface is Fw (T), and the anisotropic magnetic field Hk and the recording magnetic field strength Fw are represented by the following equations (4), (5), (6), (7) and A magnetic recording and reproducing apparatus characterized by being limited to any of the formulas (8). (Equation 4)

(5)

(6)

(Equation 7)

(Equation 8)

The method of claim 4, wherein And the anisotropic magnetic field (Hk) and the recording magnetic field strength (Fw) are limited to any one of the following equations (9), (10), (11), (12) and (13). (Equation 9)

(Equation 10)

(Equation 11)

(Equation 12)

(Equation 13)

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