JPH1116147A - Intrasurface magnetic recording medium and magnetic storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain a stable recording state even when high density recording is performed and also to enhance a leakage magnetic flux density from the surface of a medium by forming a recording bit in the direction where the magnetization of the medium is made approximately in parallel to the medium surface and in the direction approximately orthogonal to the direction of a recording track and forming an auxiliary bit that is approximately reverse to the recording bit in the magnetization direction on the both end parts of the recording track direction. SOLUTION: A medium is formed by providing a base film 0602 consisting of Cr or an alloy comprising Cr, a magnetic film 0603 consisting of an alloy comprising Co and a protective film 0604 comprising C in turn on a disk like substrate 0601. The magnetic characteristic of this medium makes a ratio of coersive force Hc(⊥) measured by impressing a magnetic field approximately in parallel to the medium surface and in the direction approximately orthogonal to the recording track direction of coersive force Hc(//) measured by impressing the magnetic field in the recording track direction as 1<(Hc(⊥)/Hc(//))<=2. Consequently, a signal can be recorded and reproduced in a high density, and the recording density per square inch can be made to >=2 gigabits.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium such as a magnetic drum, a magnetic tape, a magnetic disk, and a magnetic card, and a magnetic storage device, and more particularly, to an ultra-high density recording of 2 gigabits or more per square inch. The present invention relates to a magnetic recording medium and a magnetic storage device using the magnetic recording medium.

[0002]

2. Description of the Related Art With the spread of personal computers,
2. Description of the Related Art With the development of a highly information-oriented society, there is a demand for increasing the capacity of a magnetic disk device as an external storage device. For this reason, it is essential to increase the areal recording density of the magnetic disk drive.

Almost all of the products of the current magnetic disk drive are of the longitudinal magnetic recording type. FIG. 2 is a schematic diagram of the magnetization state when information is recorded by this method. Considering recording at a density of 250 kFCI in order to increase the areal recording density, the bit length in the recording track direction is 100 n.
m. The current size of magnetic particles is about 15 on average
Since it is nm, about seven magnetic particles bear magnetization in the recording track direction.

In the recording magnetization state shown in FIG. 2, a magnetic pole is generated between adjacent recording bits, and the transition portion is disturbed by the influence of magnetic interaction. Is difficult to form. In order to avoid this problem, a perpendicular magnetic recording system (Japanese Patent Publication No. 58-91) and a transversal magnetic recording system (Japanese Patent Application Laid-Open No. 7-249201) have been proposed which maintain a stable recording magnetization state even at a high density. Further, in the conventional longitudinal magnetic recording medium, since magnetization is alternately directed in the circumferential direction, the coercive force measured by applying an external magnetic field substantially in the circumferential direction is substantially smaller than the external magnetic field. It has a value about 1.2 to 1.5 times larger than the coercive force measured by applying the force in the radial direction.

[0005]

FIGS. 3 and 4 are schematic diagrams of recording magnetization states when signals are recorded by the perpendicular magnetic recording method and the transversal magnetic recording method, respectively. When signals are recorded by these methods, magnetizations are opposite to each other at transition portions of recording bits adjacent to each other in the recording track direction, so that an extremely magnetostatic recording magnetization state can be maintained. However, it is easy to create a closed magnetic path inside the medium,
Since the amount of magnetic flux leaking into the space is small, it is necessary to reduce the flying height of the magnetic head in order to detect a large signal.
When the magnetic head flies low, the magnetic head collides with the surface of the medium or the like, thereby deteriorating the sliding resistance and causing a problem relating to the reliability of the magnetic disk drive.

According to the present invention, there is provided an in-plane magnetic recording medium suitable for a magnetic recording system which maintains a stable recording state even at the time of high-density recording and has a high leakage magnetic flux density from the medium surface, that is, a large reproduction output. A magnetic storage device is provided.

[0007]

An object of the present invention is to provide an in-plane magnetic recording medium in which recording bits are formed in a direction substantially parallel to the medium surface and substantially perpendicular to the recording track direction.
This is achieved by forming auxiliary bits having magnetization directions substantially opposite to those of the recording bits at both ends in the recording track direction.

FIG. 1 shows a schematic diagram of the magnetization state when a signal is recorded on the magnetic recording medium of the present invention. In each transition portion of the recording bit 101 and the auxiliary bit 102 adjacent in the recording track direction, the magnetizations are opposite to each other.
An extremely stable recording magnetization state can be maintained magnetostatically. On the other hand, in the transition portion between the recording bit and the auxiliary bit in the direction orthogonal to the recording track direction, the magnetization direction is reversed, and a magnetic pole is generated at this transition portion, and the magnetic flux leaking into the space increases. Although the figure shows that the auxiliary bits are completely recorded, as an extreme example, it is not necessary to completely form the auxiliary bits because a magnetic pole is generated at the transition portion microscopically even in the AC erased state. Absent. The easy axis of magnetization of the medium is
It need not be completely parallel to the media plane. When the magnetization of the medium is divided into a component parallel to the medium surface (film surface) and a component perpendicular to the medium surface,
The present invention is achieved by recording a component parallel to the film surface so as to face the above-described direction. Even in a method called conventional in-plane recording as shown in FIG. 2, magnetization of a perpendicular component can be observed at a transition portion between recording bits. Similarly, in the magnetic recording method of the present invention, it is considered that the magnetization of the perpendicular component is generated at the transition portion between the recording bit and the auxiliary bit, and at the same time, the magnetization is disturbed.

The above-described recording magnetization state can be realized on a medium as shown in FIG. Co is contained directly or on a disk-shaped substrate 601 made of an Al-Mg alloy substrate plated with Ni-P or a ceramic substrate such as glass or via a base film 602 made of Cr or an alloy containing Cr. Magnetic film 60 made of alloy
3. A protective film 604 containing at least C is sequentially formed.
At this time, if a base film is provided, there is no problem even if a film not described here is provided between the base film and the substrate for the purpose of controlling the crystal orientation and improving the adhesion. When the disk-shaped substrate mentioned here is used, the recording track direction in the recording magnetization state is a circumferential direction.

The magnetic properties of the medium were measured by applying a magnetic field in a direction substantially parallel to the medium surface and substantially perpendicular to the recording track direction, and by measuring the coercive force Hc (⊥) by applying a magnetic field in the recording track direction. Ratio of coercive force Hc (//) Hc (⊥) / Hc
It is important that (//) be 1 or more and 2 or less in order to stabilize the recording bit.

If the coercive force ratio Hc (⊥) / Hc (//) is smaller than 1, the disturbance of magnetization increases at the transition between the recording bit and the auxiliary bit, and the medium noise increases, which is not preferable. . On the other hand, the coercive force ratio Hc (⊥) / Hc
If (//) is larger than 2, the degree of demagnetization due to the re-recording phenomenon at the time of writing information is undesirably increased. Considering these phenomena, the coercive force Hc (⊥) measured by applying a magnetic field in a direction substantially parallel to the medium surface and substantially perpendicular to the recording track direction, and the coercive force Hc measured by applying a magnetic field in the recording track direction (//) ratio Hc (⊥) / Hc (//)
Is more preferably not less than 1.05 and not more than 1.6.

The substrate may be subjected to texturing. When the substrate temperature is increased, Hc (//) is generally 1.2 to 1.0 in comparison with Hc (⊥) when the substrate temperature is increased.
It is about five times larger. However, by setting the substrate temperature to room temperature, Hc (⊥) can be made higher than Hc (//) as in the medium of the present invention. Furthermore, texturing for anti-adhesion of the magnetic head slider is not performed in the circumferential direction,
Even if it is formed radially, Hc (⊥) can be made higher than Hc (//).

In the present invention, the recording bits are formed by directing the magnetization in a direction substantially perpendicular to the recording track direction, but the deviation may be in the range of -45 degrees to +45 degrees. In a magnetic disk drive, due to the influence of the yaw angle of the magnetic head,
The magnetization of the medium may deviate from the direction perpendicular to the recording track in the range of -45 degrees to +45 degrees in the plane. However, the gist of the present invention is that the in-plane component of the magnetization of the medium becomes parallel at the transition between the recording bits, and auxiliary bits whose magnetization directions are substantially opposite to the recording bits in the plane at both ends of the recording track. Since formation is important, the direction of magnetization relative to the recording track does not matter.

In order to form the recording magnetization state of the present invention, four magnetic poles are arranged in a direction substantially perpendicular to the recording track direction, and each magnetic pole is magnetically coupled with an adjacent magnetic pole to form three magnetic poles. A write-only recording head element having a magnetic core is used. At this time, in the center magnetic core (main magnetic pole) formed by the two center magnetic poles and the magnetic cores (auxiliary magnetic poles) arranged at both ends, the in-plane components of the recording magnetic field formed by the respective magnetic poles are substantially opposite to each other. The recording operation is performed so that

As shown in FIG. 5, this recording operation can be performed by reversing the winding directions of the coils of the magnetic core (main magnetic pole) 501 'at the center and the magnetic cores (auxiliary magnetic poles) 501 "at both ends. As for the recording head element, four magnetic poles are arranged in a direction substantially perpendicular to the recording track direction, but in the range of -45 degrees to +45 degrees from the direction perpendicular to the recording track for the same reason as described above. It may be shifted.

A signal from the recording bit formed in this manner is applied to a reproducing head element (MR) utilizing a magnetoresistance effect using a magnetic material such as permalloy having a structure as shown in FIG.
Head element 701 can be used for detection. When an MR head element is used, the width of the MR head element in the direction perpendicular to the recording track direction (reproduction track width) is made smaller than the track width of the recording bit formed by the main magnetic pole, and the transition with the auxiliary bit is performed. It is more preferable that the MR head element is not applied to the portion because the medium noise is not strongly detected. The track width of the recording bit is
It is determined by the width and gap length of the main magnetic pole of the recording head element. Therefore, it is preferable that the track width of the MR head element is equal to or smaller than the sum of the width of the main pole and the gap length.

The recording head element and the MR head element are formed on one magnetic head slider. FIG. 10 (a)
FIG. 3 is a diagram showing a relative positional relationship between a recording head element and an MR head element in a magnetic head slider of the present invention, as viewed from a surface facing a medium surface. The recording head core is the center 2
It comprises one main magnetic pole 1001 and two auxiliary magnetic poles 1002 arranged on both sides thereof. 1003 is an MR head element, and 1004 is a shield film. Midpoint 100 of the line connecting the centers 1005 and 1006 of the two main poles
7 (hereinafter referred to as the center of the recording head) and a perpendicular line 1009 drawn from a straight line 1008 passing through the centers of the two main magnetic poles.
And the angle θ formed by a straight line 1011 connecting the center 1007 of the recording head and the center 1010 of the MR head element is −45 degrees or more.
It is preferable to be in the range of +45 degrees. If the relative position between the recording head element and the MR head element is out of this range, it is difficult to accurately position the MR head element on the recording bit formed by the recording head element.

Further, in order to detect a signal with high sensitivity,
As shown in FIG. 8, a magnetic flux introduction unit that sucks a magnetic flux leaking from the medium immediately above the transition between the recording bit and the auxiliary bit.
Preferably, 801 is arranged. This magnetic flux introduction part 801
Is composed of a soft magnetic material so that the magnetic flux can be efficiently
It can be led to the head element 802.

In order to limit the magnetic flux leakage from the medium, FIG.
When both sides of the MR element portion 902 are sandwiched between shields 903 made of a film having a high magnetic permeability as shown in FIG.
It is particularly preferable in that it can detect only the leakage magnetic flux from directly below the section and enhance the resolution.

The relative positional relationship between the magnetic flux introduction portion of the MR head element and the recording head element is preferably as shown in FIG. FIG. 10B is a diagram showing the relative positional relationship between the recording head element and the magnetic flux introduction portion of the MR head element in the magnetic head slider of the present invention, as viewed from the surface facing the medium surface. The recording head core is the center 2
It comprises one main magnetic pole 1021 and two auxiliary magnetic poles 1022 arranged on both sides thereof. 1023 is a magnetic flux introduction part of the MR head element, and 1024 is a shield film. A perpendicular line 1029 drawn from a midpoint 1027 (hereinafter referred to as the center of the recording head) of a line connecting the centers 1025 and 1026 of the two main magnetic poles to a straight line 1028 passing through the centers of the two main magnetic poles; A straight line 10 connecting the center 1027 of the head and the center 1030 of the magnetic flux introduction part of the MR head element
31 is preferably in the range of -45 degrees to +45 degrees. If the relative positions of the recording head element and the MR head element are out of this range, it will be difficult to accurately position the MR head element on recording bits formed by the recording head element.

In order to form the recording magnetization state according to the present invention, a considerably more complicated recording head structure is required as compared with the prior art.
To simplify this, in an in-plane magnetic recording system in which recording bits are formed in a direction substantially perpendicular to the recording track direction as shown in FIG. 12, the recording bit 1201 is located at one end in the recording track direction. Auxiliary bits 1202 that are substantially opposite in the plane may be formed. When only one auxiliary bit is used, only one magnetic pole is generated.Therefore, the leakage magnetic flux is slightly reduced as compared with the case where the auxiliary bit is provided on both sides, but a sufficiently large output is obtained as compared with the conventional transversal magnetic recording method. . Also, in this case, the recording bit is formed in a direction substantially perpendicular to the recording track direction. However, in the same manner as described above, the recording bit is shifted within a range of -45 degrees to +45 degrees from the direction perpendicular to the recording track. It does not matter. The track width of the auxiliary bits does not necessarily need to be smaller than the track width of the recording bits. In order to stabilize the auxiliary bits, it is preferable that the width is the same. To increase the track density, it is preferable to reduce the track width of the auxiliary bits.

The structure of a recording head for forming such a recording magnetization state can be simplified as shown in FIG.

With the combination of the longitudinal magnetic recording medium of the present invention and a magnetic head as described above, a magnetic storage device having a recording density of 2 gigabits per square inch or more can be achieved.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1] FIG. 1 is a schematic diagram showing the magnetization state of a longitudinal magnetic recording medium of the present invention during signal recording. At both ends of the recording bit 101 magnetized in a direction substantially perpendicular to the recording track direction, auxiliary bits 102 magnetized in a direction substantially opposite to the recording bit in a plane. Such a recorded magnetization state is shown in FIG.
The recording head can be formed by a recording head as shown in FIG. The recording head core 501 has four magnetic poles arranged in a direction substantially perpendicular to the recording track direction, and has a central core (main magnetic pole) 501 ′ and cores (auxiliary magnetic poles) 501 ″ at both ends.
In, the winding direction of the coil 502 is reversed. A recording current flows from a current source 503 to generate a recording magnetic field 504. With this magnetic field, the recording bit 505 and the auxiliary bit 506 having a substantially opposite magnetization in the plane thereof are formed.
Although the schematic diagram of this recording head is described in an easy-to-understand manner in order to show the principle, it is more preferable to use a thin-film head in practical use.

The above-described recording magnetization state can be realized on a medium as shown in FIG. A base film 6 made of at least Cr or an alloy containing Cr is formed on a disk-shaped substrate 601 made of an Al-Mg alloy substrate plated with Ni-P or a ceramic substrate such as glass.
02, and a magnetic film 6 made of an alloy containing Co is provided thereon.
03, a protective film 604 containing at least C is sequentially formed.

Here, it is particularly important that the magnetic characteristics of the medium include the coercive force Hc (⊥) measured by applying a magnetic field in a direction substantially parallel to the medium surface and substantially perpendicular to the recording track direction, and the recording track direction. Hc measured by applying a magnetic field to
(//) The ratio Hc (⊥) / Hc (//) is to be 1 or more and 2 or less. More preferably, the coercive force Hc (⊥) measured by applying a magnetic field in a direction substantially parallel to the medium surface and substantially perpendicular to the recording track direction and the coercive force Hc (//) measured by applying a magnetic field in the recording track direction. ) Ratio Hc (⊥) / Hc (//) is not less than 1.05 and not more than 1.6.

Information recorded by the magnetic recording method of the present invention can be read by a reproducing head as shown in FIG. Since a magnetic pole is generated at the transition between the recording bit 703 and the auxiliary bit 704, the magnetic flux 702 leaks into the space. When the reproducing head composed of the MR element 701 is moved just above the recording bit, the magnetoresistance of the MR element changes according to the direction of the magnetic flux leakage from the recording bit. At this time,
If a constant current is passed through the MR element, a change in the direction of the leakage magnetic flux can be detected as a change in voltage. It is more preferable to make the track width of the MR element narrower than the width of the recording bit so that the MR element does not cover a transition portion between the auxiliary bit and the auxiliary bit because the medium noise is not strongly detected.

In order to detect a signal with high sensitivity,
It is desirable to use a reproducing head having a structure as shown in FIG. Magnetic flux leakage 803 from the medium is recorded bit 804
The density is highest immediately above the transition between the bit and the auxiliary bit 805.
The head is positioned so that the magnetic flux introducing portion 801 for absorbing the magnetic flux is disposed at this position, and a large amount of magnetic flux is supplied to the MR element 8.
02, a high reproduction output can be obtained. As the MR element, it is preferable to use a GMR element utilizing a giant magnetoresistance effect in addition to a normal MR element such as Permalloy, since a large reproduction output can be obtained.

It is particularly preferable to limit the leakage magnetic flux from adjacent recording bits at the time of reproduction so that only the leakage magnetic flux directly below the reproduction head is detected, in order to increase the resolution. For this purpose, as shown in FIG. 9, it is effective to sandwich both sides of the MR element portion with a shield 903 made of a film having a high magnetic permeability.

The recording head and the reproducing head described above are
As viewed from the sliding surface, as shown in FIG. 10 (b), they are arranged on one slider base. At this time, the center 10 of the recording head
27 and the center 10 of the magnetic flux introduction part 1023 of the MR head element
30 and an angle θ formed by a perpendicular 1029 to the arrangement of the main magnetic poles of the recording head is −45 degrees to +4 degrees.
It is preferable to arrange each element so as to be in a range of 5 degrees.

A recording / reproducing test was performed on the present invention and the conventional longitudinal recording medium by the longitudinal magnetic recording method for forming the above-mentioned recording magnetization state. As a result, the dependence of the reproducing output on the recording density as shown in FIG. Obtained. The reproduction output is standardized with a 5 kFCI signal as 100%. As recording conditions,
The recording bit width (track width) was 800 nm and the auxiliary bit width was 200 nm. The reproduction condition is shield interval 2
A normal reproducing element as shown in FIG. 7 was used as the MR element, and the reproducing track width was 700 nm. The coercive force Hc measured by applying a magnetic field in a direction substantially parallel to the medium surface of the magnetic recording medium of the present invention and substantially perpendicular to the recording track direction.
(⊥) is 2500 Oe, the coercive force Hc (//) measured by applying a magnetic field in the recording track direction is 2200 Oe, and the ratio Hc (⊥) / Hc (//) of these coercive forces is 1.14. is there. On the other hand, Hc (⊥) of the medium used in the comparative example is 2200O
e, Hc (//) is 2500 Oe, and this ratio Hc (⊥)
/ Hc (//) is 0.88. It can be seen that in the longitudinal magnetic recording method for forming the above-described recording magnetization state, the magnetic recording medium of the present embodiment can record and reproduce to a higher density.

[Second Embodiment] In order to form the recording magnetization state shown in the first embodiment, a considerably complicated head structure is required as compared with the prior art. To simplify this, the recording bit 1 is set in a direction substantially orthogonal to the recording track direction as shown in FIG.
In the in-plane magnetic recording method for magnetizing 201, an auxiliary bit 1202 that is substantially opposite to the recording bit in the plane may be formed at one end in the recording track direction. When only one auxiliary bit is used, charging occurs only on one side, so the leakage magnetic flux is slightly reduced as compared with the case where there are auxiliary bits on both sides, but a sufficiently large output can be obtained compared with the conventional transversal magnetic recording method. .

The structure of the recording head for forming the recording magnetization state as in this embodiment can be simplified as shown in FIG. The recording head core 1301 has three magnetic poles arranged in a direction substantially perpendicular to the recording track direction.
The winding direction of the coil 1302 is reversed between the core forming 305 and the core forming the auxiliary bit 1306. A recording current is passed from a current source 1303 to generate a recording magnetic field 1304.
Generate. Due to this magnetic field, the recording bit 1305 and the auxiliary bit 130 having a substantially opposite magnetization in the plane with the recording bit 1305.
6 is formed. The track width of the auxiliary bit need not necessarily be smaller than the track width of the recording bit, and may be the same. To stabilize the auxiliary bits,
It is preferable that the track widths of the auxiliary bits and the recording bits be the same. When it is desired to increase the track density, the track width of the auxiliary bits may be reduced.

As shown in FIGS. 14 and 15, a signal having the same structure as in the first embodiment can be used for signal reproduction.

In a magnetic storage device using an in-plane magnetic recording medium for recording signals by the magnetic recording method described above,
The recording density per square inch can correspond to 2 gigabits or more, and a high-density magnetic storage device having a storage capacity three times or more that of a conventional magnetic storage device can be realized. Further, in the embodiments, examples of a disk-shaped magnetic recording medium and a magnetic storage device using the same have been described, but the present invention relates to a tape-shaped or card-shaped magnetic recording medium having a magnetic layer only on one side, It goes without saying that the present invention can be applied to a magnetic storage device using a magnetic recording medium.

[0036]

According to the present invention, there is provided an in-plane magnetic recording medium in which a recording bit is formed by a magnetic field from a magnetic head so that the magnetization of the medium is oriented substantially parallel to the medium surface and substantially perpendicular to the recording track direction. A signal can be recorded and reproduced at a high density by forming an auxiliary bit having a magnetization direction substantially opposite to that of the recording bit in the plane at one end or both ends. Four or three magnetic poles are arranged in a direction substantially perpendicular to the recording track direction with this medium, and each magnetic pole is magnetically coupled to an adjacent magnetic pole to form three or two magnetic cores. By combining the recording head element described above with a read-only head utilizing the magnetoresistive effect, it is possible to realize a magnetic storage device having a recording density per square inch of 2 gigabits or more.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a recording magnetization state by a magnetic recording device of the present invention.

FIG. 2 is a schematic diagram of a recording magnetization state by a conventional in-plane magnetic recording device.

FIG. 3 is a schematic diagram of a recording magnetization state by a conventional perpendicular magnetic recording device.

FIG. 4 is a schematic diagram of a recording magnetization state according to a conventional in-plane transversal magnetic recording method.

FIG. 5 is a schematic diagram illustrating an example of a recording head according to the invention.

FIG. 6 is a sectional view showing an example of the medium of the present invention.

FIG. 7 is a schematic view showing an example of a reproducing method in the magnetic recording device of the present invention.

FIG. 8 is a schematic view showing an example of a reproducing method in the magnetic recording device of the present invention.

FIG. 9 is a schematic view showing an example of a reproducing method in the magnetic recording device of the present invention.

FIG. 10 is a plan view showing an example of an arrangement of head members as viewed from a sliding surface of the magnetic head of the present invention.

FIG. 11 is a diagram showing the recording density dependency of the reproduction output in the magnetic recording device of the present invention.

FIG. 12 is a schematic diagram of a recording magnetization state by the magnetic recording device of the present invention.

FIG. 13 is a schematic diagram illustrating an example of a recording head according to the invention.

FIG. 14 is a schematic view showing an example of a reproducing method in the magnetic recording device of the present invention.

FIG. 15 is a schematic view showing an example of a reproducing method in the magnetic recording device of the present invention.

[Explanation of symbols]

101: recording bit, 102: auxiliary bit, 201: recording bit, 301: recording bit, 401: recording bit,
501: recording head core, 501 ': main magnetic pole, 501 "
... Auxiliary magnetic pole, 502 ... Coil, 503 ... Current source, 504
... Recording magnetic field, 505 recording bit, 506 auxiliary bit, 601 601 ′ substrate, 602 602 ′ base film, 603 603 ′ magnetic film, 604 604 ′ protective film, 701 MR element 702: leakage magnetic flux, 703 ...
Recording bit, 704: auxiliary bit, 801: magnetic flux introduction unit, 802: MR element, 803: leakage magnetic flux, 804: recording bit, 805: auxiliary bit, 901: magnetic flux introduction unit,
902: MR element, 903: shield, 904: magnetic flux leakage, 905: recording bit, 906: auxiliary bit, 100
DESCRIPTION OF SYMBOLS 1 ... Main magnetic pole, 1002 ... Auxiliary magnetic pole, 1003 ... MR head element, 1004 ... Shield, 1005 ... Center of main magnetic pole, 1006 ... Center of main magnetic pole, 1007 ... Center of recording head, 1008 ... Center of two main magnetic poles Straight line, 10
Perpendicular to 09 ... 1008, 1010 ... center of MR head element, 1011 ... straight line connecting 1007 and 1010, 1
021 ... Main magnetic pole, 1022 ... Auxiliary magnetic pole, 1023 ... MR
Magnetic flux introduction part of head element, 1024 ... shield, 102
5: Center of main magnetic pole, 1026: Center of main magnetic pole, 1027
... the center of the recording head, 1028 ... a straight line passing through the centers of the two main magnetic poles, 1029 ... the normal to 1028
... Center of magnetic flux introduction portion of MR head element, 1031...
A straight line connecting 27 and 1030, 1201 ... recording bit,
1202: auxiliary bits, 1301: recording head core, 1
302: coil, 1303: current source, 1304: recording magnetic field, 1305: recording bit, 1306: auxiliary bit, 1
401 MR element, 1402 leakage magnetic flux, 1403 recording bit, 1404 auxiliary bit, 1501 magnetic flux introduction part, 1502 MR element, 1503 leakage magnetic flux, 150
4 ... recording bit, 1505 ... auxiliary bit.

Continuing on the front page (72) Inventor Tetsuya Kanbe 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Inside the Hitachi, Ltd. Central Research Laboratory (72) Inventor Ichiro Tamai 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Inside

Claims (5)

[Claims] An in-plane magnetic recording medium in which recording bits are formed by a magnetic field from a magnetic head so that the magnetization of the medium is oriented substantially parallel to the surface of the medium and in a direction substantially orthogonal to the recording track direction. The ratio Hc (⊥) / Hc of the coercive force Hc (⊥) measured by applying a magnetic field in a direction substantially perpendicular to the recording track direction and the coercive force Hc (//) measured by applying a magnetic field in the recording track direction (//) is 1 or more and 2 or less, a longitudinal magnetic recording medium. 2. The longitudinal magnetic recording medium according to claim 1, wherein a coercive force Hc (⊥) measured by applying a magnetic field in a direction substantially parallel to the medium surface and substantially perpendicular to the recording track direction and the recording track direction. An in-plane magnetic recording medium, wherein a ratio Hc (⊥) / Hc (//) of a coercive force Hc (//) measured by applying a magnetic field is 1.05 or more and 1.6 or less. 3. The longitudinal magnetic recording medium according to claim 1, wherein said magnetic recording medium has a magnetic layer formed directly or via a base on a disk-shaped substrate, and said recording track direction. Is a circumferential direction of the disk-shaped substrate. 4. A longitudinal magnetic recording medium according to claim 1, wherein said longitudinal magnetic recording medium is magnetized in a direction substantially parallel to the medium surface and substantially perpendicular to said recording track direction. A magnetic storage device comprising: a recording head element for forming a bit; and a reproducing head element utilizing a magnetoresistance effect for reproducing a signal from the recording bit. 5. A magnetic storage device according to claim 4, wherein at least one end or both ends of said recording track has a magnetization direction substantially parallel to a medium surface and substantially equal to a magnetization direction of said recording bit. A magnetic storage device comprising means for forming a reverse auxiliary bit.