JP3441417B2 - Magnetic recording head and magnetic recording device using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording head and a magnetic recording apparatus using the same, and more particularly, the present invention records magnetic information in a state where a medium is heated by irradiating light. The present invention relates to a magnetic recording head that can eliminate the need for a coil for generating a recording magnetic field in optically assisted magnetic recording, and a magnetic recording apparatus using the same.

[0002]

2. Description of the Related Art A magnetic recording device for magnetically recording and reproducing information continues to develop as a large-capacity, high-speed, inexpensive information storage means. In particular, the development of hard disk drives (HDD) has been remarkable in recent years, and the recording density is 1 at the product level.
0 Gbpsi (Giga bits per squr
e Inch), the internal data transfer rate is 100 Mbp
s (Mega bits per second), and the cost per megabyte has dropped to a few yen / MB.
The densification of HDD has been progressing as a culmination of several elemental technologies such as signal processing, mechanical servo, head, medium, HDI, etc. In recent years, the thermal disturbance problem of the medium has become an obstacle to densification of HDD. It is becoming apparent.

Higher magnetic recording density is realized by miniaturizing the recording cell (recording bit) size. However, since the signal magnetic field strength from the medium is reduced by the miniaturization of the recording cell, a predetermined signal-to-noise ratio ( In order to secure S / N), reduction of medium noise is essential. The main cause of medium noise is the disorder of the magnetic transition portion, and the magnitude of the disorder is proportional to the magnetization reversal unit of the medium. A thin film made of polycrystalline magnetic particles (referred to as “multi-particle thin film” or “multi-particle medium” in the present specification) is used as the magnetic medium. When magnetic exchange interaction is exerted between particles, it is composed of a plurality of exchange-coupled magnetic particles.

Conventionally, for example, from several 100 Mbps to several G
At the recording density of bpsi, the noise reduction of the medium is
This has been achieved mainly by reducing the exchange interaction between magnetic particles and reducing the magnetization reversal unit. Latest 10Gbp
In the si-class magnetic medium, the magnetization reversal unit is magnetic particles 2-3.
It has been reduced to the number of particles, and in the near future, the magnetization reversal unit is expected to be reduced to one magnetic particle.

Therefore, in order to further reduce the magnetization reversal unit and secure a predetermined S / N in the future, it is necessary to reduce the size of the magnetic particle itself. If the volume of the magnetic particles is V, the magnetic energy of the particles is represented by KuV.
Here, Ku is the magnetic anisotropy energy density of the particles.
When V is reduced to reduce noise, KuV is reduced and the recorded information is disturbed by thermal energy near room temperature.
The heat agitation problem of becoming apparent.

According to the analysis by Shallok et al., The ratio of magnetic energy to thermal energy (kT; k: Boltzmann's constant, T: absolute temperature) of particles, KuV / kT, is not about 100. Spoil. The CoCr-based alloy Ku (2-
With 3 × 10 ⁶ erg / cc), it is becoming difficult to secure thermal agitation resistance as the particle size is reduced to reduce noise.

Therefore, in recent years, CoPt, FePd, etc. 10
Magnetic film materials exhibiting Ku of ⁷ erg / cc or more have been attracting attention, but another problem becomes apparent if Ku is simply increased in order to achieve both grain size reduction and thermal agitation resistance. It is a matter of recording sensitivity. That is, K of the medium magnetic film
When u is increased, the recording coercive force Hc0 of the medium (Hc0 = Ku /
It is defined as Isb, where Isb represents the net magnetization of the magnetic film of the medium) and the magnetic field required for saturation recording increases in proportion to Hc0.

The recording magnetic field generated from the recording head and applied to the medium depends on the recording magnetic pole material, the magnetic pole shape, the spacing, the type of the medium, the film thickness, etc., in addition to the current supplied to the recording coil. Considering that the size of the tip of the recording magnetic pole is reduced with the increase in the number of the magnetic poles, the magnitude of the generated magnetic field is limited.

For example, even in the combination of the single magnetic pole head having the largest magnetic field generated and the soft magnetic backing perpendicular medium, the magnitude of the recording magnetic field is limited to about 10 kOe (Oe: Oersted) at most. On the other hand, in order to obtain sufficient thermal agitation resistance with a particle size of about 5 nm, which is required for future high density and low noise media,
It is necessary to employ a magnetic film material exhibiting a Ku of 10 ⁷ erg / cc or more, but in that case, the magnetic field required for recording on the medium near room temperature is slightly higher than 10 kOe, and recording cannot be performed. Therefore, if the Ku of the medium is simply increased, the problem that the recording itself cannot be performed becomes apparent.

As described above, in the magnetic recording using the conventional multi-particle type medium, there is a trade-off relationship between the noise reduction, the thermal disturbance resistance, and the recording sensitivity, which limits the recording density. It became an essential issue to decide.

As a method of solving this problem, an optically assisted magnetic recording system is considered. In an optically assisted magnetic recording method using a multi-particle medium, it is desirable to use magnetic particles that are fine enough to reduce noise sufficiently and to use a recording layer that exhibits a high Ku near room temperature in order to secure thermal agitation resistance. . In a medium having such a large Ku, the magnetic field required for recording exceeds the magnetic field generated by the recording head and recording is impossible near room temperature. On the other hand, in the optically assisted magnetic recording method, a medium heating means using a light beam or the like is arranged in the vicinity of the recording magnetic pole, and the medium is locally heated at the time of recording, and Hc0 of the heating portion is set to the recording magnetic field from the head. It is reduced below and recorded.

[0012]

The important points in realizing this basic concept are: (1) The recording magnetic field is supplied at the timing before the medium is cooled during or immediately after the heating to complete the recording. (2) To prevent re-inversion of recording magnetization due to the effect of thermal agitation until the medium is sufficiently cooled after recording is completed. (3) Adjacent tracks are heated by thermal agitation by heating adjacent tracks. This is to selectively heat only a minute area of the width of the recording magnetic pole so as not to destroy it.

However, if the existing semiconductor laser and the induction type magnetic head are combined, it is difficult to sufficiently bring the semiconductor laser and the magnetic head close to each other. As a result, when the medium heated by the semiconductor laser reaches under the magnetic head, the medium is cooled and Ku again rises, which makes magnetic recording difficult.

Further, in order to increase the density of magnetic recording, the recording head becomes finer and it is necessary to prepare it by microfabrication. However, this process is more complicated and costly than the conventional coil manufacturing process. Further, as the recording head is miniaturized, it becomes difficult to maintain information on the recording medium due to thermal agitation.

On the other hand, if the existing semiconductor laser device is used as the heating source, the beam spot size is large, and therefore, if the recording density is increased, cross writing or cross erase with respect to adjacent recording bits or adjacent tracks may occur. there were.

The present invention has been made on the basis of the recognition of such problems. That is, an object of the present invention is to provide a magnetic recording device capable of heating a medium with a sufficiently small light spot and at the same time sufficiently bringing a laser beam and a recording magnetic flux close to each other to perform optically assisted magnetic recording on the medium. Especially.

[0017]

In order to solve the above problems, a magnetic recording head of the present invention and a magnetic recording apparatus using the same include a semiconductor light emitting element, a ferromagnetic material, and a strain generating means. , Heating the recording medium by the light emitted from the semiconductor light emitting element to lower the coercive force of the recording portion,
A magnetic recording device capable of recording magnetic information on the recording medium by applying a recording magnetic field from the minute magnetic material to the recording portion with a reduced coercive force, wherein the ferromagnetic material is generated by the distortion generating means. By applying a strain to and changing the magnetization direction of the ferromagnetic body by the inverse magnetostriction effect,
It is characterized in that the magnetic information is recorded.

Here, a minute opening may be provided between the semiconductor light emitting device and the recording medium, and the recording medium may be irradiated with near-field light emitted through the minute opening.

Further, the strain generating means may apply the strain to the ferromagnetic material by utilizing a piezo effect. The strain generating means may have four electrodes so as to surround the periphery of the ferromagnetic body, and the magnetization direction of the ferromagnetic body can be reversed according to the voltage applied to the four electrodes. .

Further, the strain generating means may have the same semiconductor material as that of the semiconductor light emitting element as a main part.

Further, the main part of the distortion generating means is
It may be formed integrally with the light reflection layer of the semiconductor light emitting element.

Further, a diffraction grating may be provided between the semiconductor light emitting element and the recording medium.

The semiconductor light emitting device is made of InAlG.
It may have a light emitting layer made of an aN-based compound semiconductor.

In the present specification, "InAlGaN
"Based compound semiconductor" means In_xAl _yGa_zN (x ≦
1, y ≦ 1, z ≦ 1, x + y + z = 1)
The composition ratios x, y and z within the respective ranges.
In addition, semiconductors of all compositions shall be included. For example, I
nGaN (x = 0.4, y = 0, z = 0.6) is also “nitrided
"Semiconductor". Furthermore, with Group 3 elements
Replace some In, Al, Ga with B (boron)
A part of N, which is a group 5 element, is As (arsenic) or P
Those replaced with (phosphorus) are also included. this
At this time, the above-mentioned three elements (In, Al,
Ga) is included, and as a Group 5 element
Always contains N (nitrogen).

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Ferromagnetic materials used in magnetic cores generally have a magnetic easy axis in which magnetization is oriented easily,
In the absence of an external magnetic field, the magnetization tends to this easy axis. Since this easy axis direction changes due to stress (inverse magnetostriction effect), it is possible to change the magnetization direction by applying stress to the magnetic core.

In the present invention, a unique structure is adopted in which stress is applied to the magnetic core by the piezo element formed integrally with the light emitting element.

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a conceptual diagram showing a specific example of a main part configuration of a magnetic recording apparatus according to a first embodiment of the present invention. That is, FIG. 3A is a perspective view of a main part of the recording head of the optically assisted magnetic recording device.
FIG. 3B is a side view of the tip portion.

The recording head 1A of this embodiment comprises a piezo effect element 11, a SiO ₂ insulating layer 12 having a thickness of 0.05 μm arranged thereon, and a ferromagnetic substance of 60% N.
It comprises a magnetic recording head portion 13 made of an i-permalloy piece, a minute opening 14 provided in the vicinity of the head portion, and a laser diode 15 in which these magnetic head portions are arranged.

The laser diode 15 can have, for example, a "double hetero structure" in which the active layer is sandwiched from the upper and lower sides by the cladding layer. Then, a portion above the waveguide portion at the end portion thereof is removed, and the piezo effect element 11 is provided here. That is,
The piezo effect element 11 is provided close to the laser light while not substantially affecting the waveguide of the laser diode 15.

The permalloy piece constituting the magnetic recording head portion 13 is grown in the magnetic field in the direction indicated by the arrow A in the figure, and the magnetization is directed in this direction in the non-added state. The size is, for example, 0.1 micron ×
It is about 0.1 micron × 0.1 micron. Thickness 0.
Since the 1-micron permalloy piece 13 has a domain wall width of 0.1 micron, it cannot have a domain wall inside and leaks a large magnetic field to the outside.

The piezo effect element 11 is composed of a laminated body in which AlGaN layers and InGaN layers are alternately laminated in the direction shown by an arrow S in FIG.
It can be ^-11 (m / V) or more. AlGaN
The layer thickness of the layer and the InGaN layer is, for example, several tens to several hundreds.
It can be on the order of nanometers, and the number of layers is 50 to 1
It may be about 00 pairs. In addition, the piezo effect element 11
The size of is, for example, 10 microns x 10 microns x 10
It can be on the order of microns.

Electrodes 17 are provided on both ends of the piezo effect element 11.
A and 17B are provided, and by applying a voltage of about 10 V, they are relatively extended in the direction of arrow S by about 10 ⁻⁵ . This extension is the extension of the permalloy piece 13 via the SiO ₂ insulating film 12. Magnetostriction constant of permalloy is 2 × 1
Since 0 ^-5, the axis of easy magnetization of Permalloy This elongation changes the direction of arrow B. An applied voltage of 10 V may cause dielectric breakdown in a normal piezo element, but there is no such concern in an AlGaN / InGaN system.

The laser diode 15 can be formed of an AlInGaN-based material like the piezo effect element 11. For example, the laser diode 15 is sequentially formed on the sapphire substrate 10 by A.
It can be formed by epitaxially growing an lInGaN-based material. Then, when a current is injected through the electrodes 18A and 18B, the laser light L is emitted. Laser 1
A reflection layer made of, for example, a dielectric material or a metal is formed on the emission end face of 5, and a minute opening portion 14 is provided so as to be aligned with the optical axis of the laser light. The laser light emitted from the laser diode 15 generates near-field light by the minute opening 14. In the present specification, the “near-field light” may include evanescent waves.

In order to effectively utilize the heating of the recording medium by the near-field light, it is necessary to bring the opening 14 and the magnetic head portion close to each other. In the conventional optically-assisted magnetic recording head, when the magnetic head is brought close to the laser diode, the waveguide structure of the laser diode is destroyed.
Proximity placement was not easy. In the present invention, the magnetostriction effect is used to significantly reduce the magnetic head portion, and the piezo effect element 11 is formed of the same material system as the laser diode 15, so that the same substrate and the same material system are used. It became possible to form.

The magnetic recording medium M is arranged so as to face the optically assisted magnetic recording head 13. The recording medium M has a high K
It has a recording layer having a magnetic material of u. At the time of recording, the recording medium M travels in the direction of the arrow R, and the minute opening 1
After the recording layer M1 is sufficiently heated by the near-field light generated from No. 4, the recording layer M1 approaches the permalloy piece 13.

The magnetization direction of the permalloy piece 13 is the direction of arrow A in the unloaded state, and since the magnetization direction is inclined with respect to the magnetic recording medium M provided facing this, the recording layer M1. It is not possible to apply an effective recording magnetic field to the magnetic recording medium and no magnetic transition occurs. On the other hand, when strain is applied by the piezo effect element 11, the magnetization direction changes to the arrow B, so that the leakage magnetic field from the permalloy piece 13 is applied to the recording layer, and the magnetization transition can be caused. . That is, by changing the magnetization direction of the Perloy piece 13 by the piezo effect element 11,
It is possible to write magnetic information by controlling the presence or absence of the magnetic transition of the recording layer.

(Second Embodiment) Next, the second embodiment of the present invention will be described.
The embodiment will be described.

FIG. 2 is a conceptual diagram showing a main part of the optically assisted magnetic recording apparatus according to this embodiment.
Is a perspective view of an essential part of the recording head portion, and FIG. 7B is a top view of the tip portion thereof.

The recording head 1B of this embodiment uses a part of the edge emitting laser diode near the end face as a piezo effect element.

That is, in FIG. 2, the piezo effect element portion 21 is integrally provided near the end face of the laser diode 25. This is because, for example, when the laser diode 25 is formed of an AlGaInN-based material and an epitaxial layer is stacked in the direction of the arrow S, a part of the clad layer or outside the clad layer is AlGaN / I.
A DBR layer of nGaN may be inserted. The DBR layer thus formed acts as a light reflection layer in the main part of the laser diode. On the other hand, this DBR layer has the
By providing the electrodes 27A and 27B and independently applying a voltage in the stacking direction, the piezoelectric effect element portion 21 can be operated. The size of the piezo effect element portion 21 can be, for example, about 10 microns × 10 microns × 10 microns.

Here, the tip of the electrode 27A is buried inside the semiconductor layer, and is disposed so as to face the electrode 27B with the DBR structure constituting the piezo effect element portion 21 interposed therebetween. In addition to the specific example shown, the electrode 27A may be formed on the surface indicated by the arrow EL. When the electrode 27A is formed here, the electric field strength with respect to the piezo effect element portion 21 is lowered, but a voltage can be applied.

On the piezo effect element portion 21, a single crystal iron (Fe) piece 23A and a minute permanent magnet 23B are provided in series via a MgO thin film 22 for increasing the piezo effect. The size of the single crystal iron piece 23 is, for example, 0.
It can be about 2 microns × 0.3 microns × 0.05 microns. Since the domain wall width of iron is about 0.2 μm, the domain wall cannot exist inside the single crystal iron piece 23A, and a large magnetic field leaks to the outside. The easy axis of magnetization of single crystal iron is the <001> direction, but in the case of this example, the magnetization is in the direction of arrow A in the figure due to the shape anisotropy.

Since the magnetostriction coefficient of iron (Fe) is 2 × 10 ⁻⁶ and the piezoelectric constant of the piezo effect element section 21 is 10 ⁻¹¹ or more, a voltage of about 1 V should be applied to the piezo effect element section 21. Thus, as in the case of the first embodiment, the easy axis of magnetization of the single crystal iron piece 23A can be changed in the direction of arrow B.

Here, if the magnetization direction of the permanent magnet 23B is set to the direction of the arrow P, by applying a voltage to the piezo effect element portion 21, it is aligned with the magnetization direction of the single crystal iron piece 23A, and the recording medium M is recorded. A recording magnetic field is applied.

Also in this embodiment, the laser light emitted from the laser diode 25 produces near-field light in the minute aperture 24. The recording medium is heated by the near-field light and then a recording magnetic field leaking from the single crystal iron piece 23A is applied to write magnetic information.

In the present embodiment, by using the minute single crystal iron piece 23A as the magnetic pole for supplying the recording magnetic field, the size of the magnetic pole tip can be made extremely small. Therefore, it is possible to significantly reduce the recording bit size as compared with the conventional technique and to significantly increase the recording density.

(Third Embodiment) Next, the third embodiment of the present invention will be described.
The embodiment will be described.

FIG. 3 is a perspective view of a main part of the recording head of the optically assisted magnetic recording apparatus according to this embodiment.

In the recording head 1C of this embodiment, a side effect type laser diode 35 has a piezo effect element portion 31 formed near the end face thereof.

The laser diode 35 is formed by stacking epitaxial layers in the direction of arrow S in FIG. Then, similarly to the one shown in FIG. 2, AlGaN is partially formed on the cladding layer or outside the cladding layer.
/ InGaN DBR layer is inserted. The DBR layer thus formed acts as a light reflection layer in the main part of the laser diode. On the other hand, this DBR layer has the electrode 37A near the end face as shown in the figure.
And 37B and by independently applying a voltage in the stacking direction, the piezoelectric effect element section 31 can be operated. Also in this specific example, the tip portion of the electrode 37A is embedded inside the semiconductor layer, and a voltage is applied to the piezoelectric effect element portion 31 so as to face the electrode 37B.

The laser light is emitted from the upper surface of the laser diode 35. Then, by forming a layer of a dielectric material or a metal on the emitting portion and forming a slit-shaped minute opening 36 or a diffraction grating, near-field light can be produced.

On the AlGaN / InGaN superlattice structure piezo effect element portion 31 having a size of about 1 micron × 1 micron × 1 micron, a size of 0.2 micron × 0.
Single crystal iron piece 33A of about 3 microns x 0.05 microns
And a minute permanent magnet 33B is provided.

The piezo effect element section 31 includes the electrodes 3 facing each other.
It has 7A and 37B and extends in the direction of arrow S by applying a voltage. Since the domain wall width of single crystal iron (Fe) is about 0.2 μm as described above, the domain wall cannot exist inside the domain wall, and a large magnetic field leaks to the outside. The easy axis of magnetization of single crystal iron is <001>, but in this case, the magnetization is in the direction of arrow A due to shape anisotropy. The magnetostriction coefficient of iron is 2 × 10 as described above.
It is about ^-6 , and the piezoelectric constant of the piezo effect element portion 31 is 1
Since it is 0 to ¹¹ or more, considering the direction of magnetization, the easy axis of magnetization can be changed in the direction of arrow B by applying a voltage of about 0.1 V to the piezo effect element section 31.

A recording medium (not shown) is provided so as to face the minute opening 36, and magnetic information is written by the recording magnetic field leaking from the single crystal iron piece 33A after being heated by the near-field light from the minute opening 36.

In this embodiment, the permanent magnet 33B is mounted to generate a change in magnetic energy when a voltage is applied, as in the second embodiment.

Further, in this embodiment, the minute opening 3
Instead of 6, a diffraction grating can be used.

FIG. 4 is a conceptual diagram showing such a diffraction grating. That is, as shown in the figure, the diffraction grating D is formed centering on the output portion E of the laser light. With such a diffraction grating, solid immersion
A lens (solid immersion lense) can be formed and a condensing function as a Fresnel lens can be obtained.

(Fourth Embodiment) Next, the fourth embodiment of the present invention will be described.
The embodiment will be described.

FIG. 5 is a perspective view of the main part of the recording head of the optically assisted magnetic recording apparatus according to this embodiment.

The recording head 1D of the present embodiment is provided with a piezo effect element which also functions as a laser reflection mirror on the end face of an edge emitting laser diode. That is, this recording head has an AlN / InN piezo effect element / reflective window structure 41 having a size of about 3 microns × 3 microns × 1 micron. In this structure, AlN layer and In
The stacking direction of the N layers is the direction of arrow S.

The laser diode 45 is an edge emitting laser. A part of the piezo effect element / reflecting window structure 41 is provided so as to cover the front of the light emitting end face of the laser diode 45. Therefore, the structure of the DBR (distributed Bragg reflecto) has a high reflectance for laser light.
With the r) structure, an action as a reflecting surface of the laser resonator can be obtained. For this purpose, the AlN layer and the InN layer may be determined according to the wavelength of the laser light. Further, a minute opening 44 is provided at the laser light emitting portion.

A notch-like step is provided in a part of the structure portion 41, and a 0.1 μm × 0.1 μm layer is formed on this surface via a SiO ₂ insulating layer 42 having a film thickness of 0.05 μm. 1
60% Ni, which is a ferromagnetic substance of micron x 0.1 micron
A magnetic head portion 43 made of permalloy is provided.

The magnetization direction of the permalloy forming the magnetic head portion 43 is provided obliquely with respect to the optical axis of the laser light in the unloaded state. Since the permalloy having a thickness of 0.1 μm has a domain wall width of 0.1 μm, it cannot have a domain wall inside, and a large magnetic field leaks to the outside as in the first embodiment described above. .

The piezoelectric constant of the piezo effect element portion 41 is 10
^-11(M / V) or more and between the electrodes 46A and 46B
Relative to the horizontal direction by applying a voltage of 1V
To 10 ^-5Just grow. This elongation is SiO_TwoInsulation film 42
The permalloy 43 extends through the. This permalloy
Has a magnetostriction constant of 2 × 10^-5Because of this,
The easy axis of magnetization of permalloy is in the depth direction of the figure. Pie
The minute opening 44 formed in the groove is a laser diode.
A near field is generated from the laser light generated by the cord 45.
It

In order to effectively utilize the heat generated by the near field, it is necessary to bring the minute opening 44 and the magnetic head 43 close to each other. In the conventional magnetic recording element, when the magnetic head portion is brought close to the light emitting element, the waveguide structure is destroyed, and the approach is not easy.

In this embodiment, the magnetostrictive effect is used to reduce the size of the magnetic head portion, and the reflection window and the piezo effect element are made of the same material as the laser, so that the same substrate is used.
It was made possible by forming it on the element.

In the first to fourth embodiments described above, since the direction of the leakage magnetic field from the magnetic head is constant, only one of recording and erasing can be performed. Two heads may be used for recording and erasing. Alternatively, when erasing, there is also a method of erasing the record by increasing the light output.

(Fifth Embodiment) Next, the fifth embodiment of the present invention will be described.
The embodiment will be described.

FIG. 6 is a perspective view of the main part of the recording head of the optically assisted magnetic recording apparatus according to this embodiment. The recording head 1E of the present embodiment is capable of applying magnetic fields in both positive and negative directions from the magnetic head portion 53 by further improving the structure described above with respect to the fourth embodiment and providing four electrodes 57A to 57D. is there.

That is, the recording head 1E has a 3 micron × 3 micron × 1 micron AlN / InN piezo effect element / reflective window structure 51, and a SiO2 insulating layer 52 having a film thickness of 0.05 micron thereon. Provided 0.1
Magnetic head 5 made of 60% Ni permalloy, which is a ferromagnetic substance of micron x 0.1 micron x 0.1 micron
3, a minute opening 54 close to the head portion, and an AlInGaN laser diode 55 in which these magnetic head portions are arranged. The recording medium (not shown) has a minute opening 54.
Are arranged to face each other.

The magnetization of the magnetic head portion 53 is directed in the direction A perpendicular to the optical axis of the laser light in the unloaded state. Permalloy with a thickness of 0.1 micron has a domain wall width of 0.1
As described above, since it is micron, it cannot have a domain wall inside and a large magnetic field leaks to the outside.

The piezoelectric effect element portion 51 is provided with four counter electrodes 57A to 57D so as to surround the magnetic head portion 53. These four electrodes are used as two sets of opposing electrodes. At this time, if the voltages applied to the two sets of electrodes are adjusted, the piezo effect element portion extends obliquely with respect to the laser optical axis, and the shift direction of the easy axis of magnetization can be determined.

FIG. 7 is a conceptual diagram showing the relationship between the voltages applied to the four electrodes and the magnetization direction of the magnetic head portion 53 when viewed from above. When no voltage is applied, the magnetization of the magnetic head portion 53 is in the direction perpendicular to the laser optical axis, that is, in the direction substantially parallel to the medium surface, as shown in FIG.

On the other hand, as shown in FIG. 7B, the adjacent (57A, 57C) sides are adjacent (57).
B, 57D) side is negative and faces (57
A, 57D) apply a voltage so as to have a larger potential difference than (57B, 57C) facing each other, and the piezo effect element portion extends diagonally in the diagonal direction of (57A, 57D). , The magnetization of the magnetic head portion 53 shifts as shown in the figure, and when the voltage is subsequently applied as shown in Fig. 7C, the magnetization of the magnetic head portion 53 shifts further. The recording medium.

On the other hand, in the state where no voltage is applied (see FIG.
When a voltage is applied from (a)) as shown in FIG. 7D, the piezo effect element portion extends obliquely in the diagonal direction of (57B, 57C). As a result, the magnetization of the magnetic head portion 53 shifts as shown in the figure. Subsequently, when a voltage is applied as shown in FIG. 7D, the magnetization of the magnetic head portion 53 shifts further and moves away from the recording medium.

That is, by adjusting the voltages of the four electrodes 57A to 57D, it is possible to generate two types of positive and negative magnetic fields generated from the magnetic head portion 53. Since the magnetization direction can be selected to the front side or the depth side, recording / recording
It can be erased. Although this state is sufficient, there is also a method of reducing this intermediate state and further reducing the voltage difference on the same side to zero. In this case, the light output may be constant. Minute openings 54 formed in the piezo effect element / reflection window structure 51
The generation of the near field from the laser light generated by the laser diode 55 is the same as in the other embodiments.

The recording head described in relation to the first to fifth embodiments above is incorporated in, for example, a recording / reproducing integrated magnetic head assembly, and is realized as a heat-assisted magnetic recording device.

FIG. 8 is a main part perspective view illustrating the schematic structure of such a magnetic recording apparatus. That is, the thermally-assisted magnetic recording device 150 of the present invention is a device using a rotary actuator. In the figure, the longitudinal recording or perpendicular recording magnetic disk 200 is mounted on a spindle 152 and rotated in the direction of arrow A by a motor (not shown) responsive to a control signal from a drive device controller (not shown). The magnetic disk 200 may have a recording layer for longitudinal recording or perpendicular recording, and may have a “keepered medium” structure having a soft magnetic layer laminated thereon. In the magnetic disk 200, a head slider 153 for recording / reproducing information stored in the magnetic disk 200 is attached to the tip of a thin film suspension 154. Here, the head slider 153 mounts the recording head portion described above with respect to the first to fifth embodiments near the tip thereof.

When the magnetic disk 200 rotates, the medium facing surface (ABS) of the head slider 153 is held with a predetermined flying height above the surface of the magnetic disk 200.

The suspension 154 is connected to one end of an actuator arm 155 having a bobbin portion for holding a drive coil (not shown). A voice coil motor 156, which is a kind of linear motor, is provided at the other end of the actuator arm 155. The voice coil motor 156 is composed of a drive coil (not shown) wound around the bobbin of the actuator arm 155, and a magnetic circuit composed of a permanent magnet and a facing yoke that are arranged to face each other so as to sandwich the coil.

The actuator arm 155 has a fixed shaft 1
It is held by ball bearings (not shown) provided at two positions above and below 57, and can be freely rotated and slid by a voice coil motor 156.

FIG. 9 is a block diagram illustrating the overall structure of the magnetic recording apparatus of the present invention. In FIG. 9, Io is a light emitting element drive input, Is is a signal input, Os is a signal output, 2
Reference numeral 01 is a light emitting element drive circuit system, 202 is a light emitting element built in the head, 203 is an ECC (error correction code) addition circuit system, 204 is a modulation circuit system, 205 is a recording correction circuit system,
Reference numeral 206 denotes a piezo effect element portion built in the head, 207
Is a medium, 208 is a reproducing element portion built in the head, 20
Reference numeral 9 is an equivalent circuit system, 210 is a decoding circuit system, 211 is a demodulation circuit system, and 212 is an ECC circuit system.

The magnetic recording apparatus of the present invention has a block structure in which a light emitting element drive input Io, a light emitting element drive circuit system 201, and a light emitting element 202 are added to the conventional magnetic disk apparatus. The feature is that a unique recording head portion as illustrated is provided.

The light emitting element drive input may be a DC voltage supply to the laser element, and the light emitting element may be DC driven without providing a light emitting element drive circuit system. Pulsed driving may be performed in synchronism with the output of the modulation circuit. Although pulse driving complicates the circuit configuration, it is preferable for prolonging the life of the laser. The ECC addition circuit system 203 and the ECC circuit system 212 may not be provided. Mode of modulation and demodulation,
The recording correction method can be freely selected.

For information input to the medium, light irradiation from the light emitting element section 202 and a recording magnetic field modulated by the recording signal from the piezo effect element section 206 are applied to the medium position where Hc0 is lowered by this light irradiation. Especially. The point that the recorded information is formed as a magnetic transition sequence on the medium surface is the same as in the conventional magnetic recording device. At this time, according to the present invention, as described above with reference to FIGS. 1 to 7, since the laser beam for heating and the tip of the magnetic recording head can be extremely close to each other, the heating and the magnetic writing can be performed at the optimum timing. Can be done at. That is, it is possible to perform ultrahigh-density magnetic recording at ultrahigh speed.

The reproducing element section 208 detects the leakage magnetic field from the medium generated from the magnetization transition train as a signal magnetic field. The reproducing element section is typically a GMR type, but a normal AMR (an
An isotropic magnetoresistance type may be used, and a TMR (tunneling magnetoresistance) type may be adopted in the future.

The recording medium used in the magnetic recording apparatus of the present invention is not limited to a so-called hard disk, and any other medium capable of magnetic recording such as a flexible disk or a magnetic card can be used.
It is also possible to use a combination of an optical disk and a magnetic disk.

Further, the magnetic recording apparatus of the present invention may be one that carries out only magnetic recording, or one that carries out recording / reproduction. The positional relationship between the magnetic head and the medium may be so-called “floating traveling type” or “contact traveling type”. Further, it may be a so-called "removable" type magnetic recording device in which the recording medium is removable from the magnetic recording device.

The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples.

For example, the material and structure of the laser diode or the piezo effect element can be appropriately selected by those skilled in the art from known techniques and similarly used to obtain the same various effects.
For example, a so-called surface emitting element may be used as the laser diode.

As the magnetic material forming the magnetic head portion, various known materials other than permalloy and iron can be appropriately selected and used in the same manner.

In addition, the present invention can be variously modified and implemented without departing from the scope of the invention.

[0094]

As described above, according to the present invention, it is possible to provide a magnetic recording apparatus equipped with an optically assisted magnetic recording head that does not require a coil. As a result, the semiconductor laser as the heating source and the magnetic head as the magnetic writing means can be arranged close to each other. If both are arranged close to each other, it becomes possible to write magnetic information after the recording medium is heated and before it is cooled.
A medium with u can be used. As a result, even if the recording bit size is reduced, the problem of data loss due to thermal agitation disappears, and the recording density can be significantly increased as compared with the conventional case.

Further, in the present invention, since the near-field light is used as the heating source, the heating region can be extremely limited. As a result, it is possible to reduce the track size and the recording bit size while preventing cross writing and cross erasing, and it is possible to realize magnetic recording with a higher density than before.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a main part of an optically assisted magnetic recording apparatus according to a first embodiment of the present invention, and FIG. 1 (a) is a perspective view of a main part of a recording head part thereof. (B) is a side view of the tip.

FIG. 2 is a conceptual diagram showing a main part of an optically assisted magnetic recording device according to a second embodiment of the present invention, and FIG. 2 (a) is a perspective view of the main part of the recording head part. (B) is a top view of the tip.

FIG. 3 is a perspective view of a main part of a recording head of an optically assisted magnetic recording device according to a third embodiment of the invention.

FIG. 4 is a conceptual diagram showing a diffraction grating.

FIG. 5 is a perspective view of a main part of a recording head of an optically assisted magnetic recording device according to a fourth embodiment of the invention.

FIG. 6 is a perspective view of a main part of a recording head of an optically assisted magnetic recording device according to a fifth embodiment of the invention.

FIG. 7 is a conceptual diagram showing the relationship between the voltage applied to the four electrodes and the magnetization direction of the magnetic head portion 53 when viewed from above.

FIG. 8 is a perspective view of a main part illustrating a schematic configuration of a magnetic recording device.

FIG. 9 is a block diagram illustrating the overall configuration of a magnetic recording device.

[Explanation of symbols]

1A to 1E Recording heads 11, 21, 31, 41, 51 Piezo effect element portions 12, 22, 32, 42, 52 Insulating films 13, 23, 33, 34, 35 Ferromagnetic materials 14, 24, 34, 44, 54 Micro aperture 17, 27, 37, 47, 57 Electrode (for piezo effect element) 18, 28, 38, 48, 58 Electrode (for laser diode) 150 Thermally assisted magnetic recording device 152 Spindle 153 Head slider 154 Suspension 155 Actuator arm 156 Voice coil motor 160 Magnetic head assembly 200 Medium (magnetic recording disk) Io Light emitting element drive input Is Signal input Os signal output 201 Light emitting element drive circuit system 202 Light emitting element section 203 ECC (error correction code) addition circuit system 204 Modulation circuit system 205 Recording correction circuit system 206 Piezo element section 20 Medium 208 read element 209 equivalent circuit system 210 decode circuitry 211 demodulator circuit system 212 ECC circuit system

Claims (7)

(57) [Claims] 1. A semiconductor light emitting element, a ferromagnetic material, and a strain generating means, wherein the recording medium is heated and heated by the light emitted from the semiconductor light emitting element to coercive force of the recording layer of the recording medium. And a magnetic recording head capable of recording magnetic information on the recording medium by applying a recording magnetic field from the ferromagnetic material to the recording layer having a reduced coercive force, wherein the distortion generating means is The semiconductor light emitting element has the same semiconductor material as a main portion, the main portion of the strain generating means is integrally formed with a light reflection layer of the semiconductor light emitting element, and the ferromagnetic material is generated by the strain generating means. A magnetic recording head, wherein the magnetic information is recorded by applying strain to a body and changing a magnetization direction of the ferromagnetic body by an inverse magnetostriction effect. 2. A micro aperture is provided between the semiconductor light emitting device and the recording medium, and the near-field light emitted through the micro aperture is applied to the recording medium. 1. The magnetic recording head according to 1. 3. The magnetic recording head according to claim 1, wherein the distortion generating means applies the distortion to the ferromagnetic material by utilizing a piezo effect. 4. The strain generating means has four electrodes surrounding the ferromagnetic material, and the magnetization direction of the ferromagnetic material can be reversed according to the voltage applied to the four electrodes. The magnetic recording head according to claim 3, wherein 5. The magnetic recording head according to claim 1, wherein the semiconductor light emitting device is provided with a diffraction grating. 6. The magnetic recording head according to claim 1, wherein the semiconductor light emitting element has a light emitting layer made of an InAlGaN compound semiconductor. 7. A magnetic recording apparatus comprising the magnetic recording head according to claim 1.