JP2007293972A - Magnetic recording / reproducing head, magnetic recording / reproducing apparatus, and magnetic information recording / reproducing method - Google Patents

Abstract

An ultra-compact and light-weight magnetic recording / reproducing head capable of performing high-density recording and high-resolution reproduction with higher accuracy and lower power consumption at a low manufacturing cost, and a magnetic recording / reproducing apparatus including the same And a magnetic information recording / reproducing method.
In a magnetic recording / reproducing head 100, a laser light source 2 and a magnetic shield 3a are formed in parallel on a slider substrate 1 from the side facing the magnetic recording medium. On the magnetic shield 3a, the dielectric 4a, the recording element 5, the dielectric 4b, the magnetic sensor electrode layer 6a, the magnetic sensor 7, the magnetic sensor electrode layer 6b, and the magnetic shield 3b are laminated in this order. A protective film 8 is formed on the laser light source 2 and the magnetic shield 3 b, and bias layers 9 a and 9 b for applying a bias magnetic field to the magnetic sensor 7 are formed on the side of the magnetic sensor 7. The magnetic recording / reproducing apparatus of the present invention includes a magnetic recording / reproducing head 100.
[Selection] Figure 1

Description

  The present invention increases the temperature of a magnetic recording medium using near-field light while applying a recording magnetic field to record magnetic information on the magnetic recording medium, and increases the temperature of the magnetic recording medium using near-field light to perform magnetic recording. MAGNETIC RECORDING / REPRODUCING HEAD USED FOR OPTICAL-ASSISTED MAGNETIC RECORDING / REPRODUCING METHOD FOR REPRODUCING RECORDING INFORMATION RECORDED ON MEDIUM, MAGNETIC RECORDING / REPRODUCING DEVICE HAVING THE MAGNETIC RECORDING / REPRODUCING HEAD, AND The present invention relates to a magnetic information recording / reproducing method using.

In the field of magnetic recording represented by a hard disk, a recording medium, a recording head, the characteristics improve reproduction head, is achieved recording density exceeding 200 Gbit / inch ² in areal density, it is followed by a further increase in density. Various magnetic recording systems and magnetic reproduction systems have been proposed to cope with this improvement in recording density.

However, in the current magnetic recording system used for hard disks, the problem of thermal fluctuation of the magnetic recording medium has been pointed out, and it is difficult to keep magnetic information stably for a long time as the recording density increases. It is known to be. The problem of the above thermal fluctuation is that the magnetic anisotropy energy vK _u , which is the product of the volume v of the magnetic particles forming the magnetic bit of the magnetic recording medium and the magnetic anisotropy energy constant K _u , and the thermal energy kT (k : Boltzmann constant, T: expressed in relation to the temperature), magnetic anisotropy energy vK _u is the reduced to several tens of times the thermal energy kT, thermal fluctuations are known to be significant. In a high-density magnetic recording medium, it is necessary to use a material having a large K _u for the recording medium in order to solve the above-described thermal fluctuation problem. However, increasing the K _u simultaneously increases the coercive force H _c . It leads to enlargement. When the coercive force H _c is increased, will be increased magnetic field required for recording, which can be output from the recording head, since outweighs the upper limit of the writable magnetic field, the magnetic recording system using only conventional magnetic field There are limits.

As a method for recording magnetic information on a magnetic recording medium such high K _u, using a laser beam, temporarily lowers the coercivity H _c by heating the medium during recording, which is the heating An optically assisted magnetic recording method has been proposed in which an external magnetic field is applied to a portion to record magnetic information. According to such an optical-assisted magnetic recording method, recording with a relatively small magnetic field with respect to good thermal stability high K _u medium are possible, and stably hold the raised even information recording density Since this is possible, loss of recorded information can be prevented.

  Furthermore, in optically assisted magnetic recording, since the size of the recording bit is determined according to the size of the heating area on the recording medium, if the heating area is reduced, a minute recording bit can be formed even if the external magnetic field application area is large, High density recording can be achieved. For this reason, many optically assisted magnetic recording methods using near-field light that can make the spot diameter smaller than the light source wavelength of the laser beam that is a heating source have been proposed. In this patent document 1, near-field light is generated by using a cone-shaped probe whose surface is coated with a metal film or a probe having a minute opening formed at the tip of a cone, and performs optically assisted magnetic recording. A method is disclosed.

  On the other hand, in the optically assisted magnetic recording using near-field light, it is necessary to apply an external magnetic field for reversing the magnetization of the recording bit together with the medium heating by the near-field light. However, since the reach distance of the near-field light is very close to the near-field light generating element (less than the size of the minute shape that generates the near-field light), the magnetic bit is reversed in magnetization relative to the heating area on the magnetic recording medium. In order to apply an external magnetic field that is sufficiently large to generate a magnetic field, it is important to provide a magnetic field generation source in the immediate vicinity of the near-field light generating element.

  Next, as a magnetic reproduction method used for the current hard disk, a method called an optically assisted reproduction method has been proposed from the viewpoint of reading out magnetic information recorded on a magnetic recording medium with high resolution with high resolution. This is because a magnetic recording medium on which magnetic information is recorded is irradiated with a laser beam, the magnetic recording medium is locally heated to a temperature lower than that at the time of recording, and a leakage magnetic field generated from the heating area is detected using a magnetic sensor. This is a playback method that detects the above. At this time, the material and composition of the recording medium are adjusted so that a leakage magnetic field is not generated so much from the non-heated area of the magnetic recording medium, and a large leakage magnetic field is generated from the heating area. Thereby, in the magnetic sensor, the leakage magnetic field from the heating region can be detected relatively strongly, and crosstalk from adjacent tracks can be reduced. In such an optically assisted reproduction, an area to be reproduced (a large leakage magnetic field is generated) is determined according to the size of the heating area on the recording medium. Therefore, the heating area is set by using a near-field light source as a heating source. If the size is reduced, minute recording bits can be reproduced with high resolution.

  As an example of a configuration using such a near-field light source and a magnetic sensor, the following Patent Document 2 can be cited. This Patent Document 2 discloses a light that includes a coil that records information by applying a magnetic field around a laser beam exit, and a magnetic sensor that is disposed inside the coil and detects information recorded on a magnetic recording medium. An assist magnetic head is disclosed, and an optically assisted magnetic head including a plasmon exciter that enhances laser light emitted from a laser light exit or a light shield that has an opening that reduces the size is also disclosed. Patent Document 2 discloses that the distance between the laser light exit port and the spin valve film of the magnetoresistive sensor can be reduced to 2 to 3 μm, and assembly adjustment is facilitated. It is also described that it is possible to simultaneously track on the same narrow track.

JP-A-11-265520 JP 2003-203304 A

  In the recording / reproducing method in which both optically assisted magnetic recording and optically assisted reproduction as described above are performed using near-field light, a near-field light source is composed of a recording element and a magnetic sensor from the viewpoint of cost reduction and head weight reduction. It is desirable to share. That is, it is desirable that each of the laser light source and the near-field generation source be single. However, in the magnetic sensor used in the current hard disk, a magnetic shield having a thickness of about 500 nm to 3 μm is generally formed on both sides of the magnetic sensor (track length direction of the magnetic recording medium) in contact with the magnetic sensor. Is. On the other hand, the reach distance of near-field light emitted from a near-field light source is about the size of a minute shape that generates near-field light, and the near-field light source formed on the recording element is also used for light-assisted reproduction. For example, a magnetic shield of about 500 nm to 3 μm as applied to a conventional magnetic sensor is formed on a recording element because the shield is thick and the distance between the near-field generation source and the magnetic sensor is too large. The heating region of the magnetic recording medium heated by the single near-field generation source is naturally cooled before reaching the magnetic sensor as the medium moves, and there is a problem that optically assisted reproduction cannot be realized. Thus, when trying to realize optically assisted magnetic recording / reproducing using a single near-field light source, the conventional magnetic shield thickness has been problematic in that it naturally cools before reaching under the magnetic sensor. It has not been pointed out, and of course no solution has been shown.

  Patent Document 2 discloses an optically assisted magnetic head that can reduce the distance between the laser light exit port and the spin valve film of the magnetoresistive sensor. This distance is as large as 2 to 3 μm, which is much larger than the distance that the near-field light reaches, and is not a sufficient distance for performing light-assisted reproduction. In addition, in the optically assisted magnetic head disclosed in Patent Document 2, a coil for applying a magnetic field is connected to the laser beam exit port and the magnetoresistive sensor in order to bring the laser beam exit port close to the magnetoresistive sensor. In order to generate a sufficient recording magnetic field in the vicinity of the laser beam exit, as a result, the entire length of the coil is increased and the area of the region surrounded by the coil is increased. There was a problem of requiring large power consumption.

  Therefore, an object of the present invention is to enable efficient and accurate optically assisted magnetic recording and optically assisted reproduction even when a single near-field light source is used. High-resolution reproduction can be performed with high accuracy, and furthermore, a magnetic recording / reproducing head, a magnetic recording / reproducing apparatus, which can realize a magnetic recording / reproducing head that is low in manufacturing cost, ultra-compact and lightweight, Another object of the present invention is to provide a magnetic information recording / reproducing method using them. It is another object of the present invention to provide a magnetic recording / reproducing head and a magnetic recording / reproducing apparatus in which a near-field light generating portion does not leave a magnetic sensor even when the magnetic shield is thickened.

Means and effects for solving the problems

(1) The magnetic recording / reproducing head of the present invention uses a near-field light while applying a recording magnetic field to raise the temperature of the magnetic recording medium to record magnetic information on the magnetic recording medium, and uses the near-field light to record the magnetic information. A magnetic recording / reproducing head used in an optically assisted magnetic recording / reproducing system for reproducing recorded information recorded on a magnetic recording medium by raising the temperature of the medium, comprising a non-magnetic material, a pair of electrodes, and the pair of electrodes A recording element having a conductive constriction portion electrically connected to each of the recording element and a magnetic sensor for reproducing recorded information recorded on a magnetic recording medium, and when the constriction portion is irradiated with laser light Near-field light is generated using a local shape change portion formed in the constricted portion as a source, and when a current flows between the pair of electrodes, a magnetic field is generated using the constricted portion as a source, and the constricted portion and Position to sandwich the magnetic sensor Further comprising a pair of magnetic shield layer provided.

  According to the above configuration, the recording element made of a non-magnetic material that does not affect the magnetic sensor (no magnetic field is generated) when de-energized (during reproduction) is used, and the recording element that is the near-field light generation position is constricted. The local shape change part formed in the part can be arranged in the very vicinity of the magnetic sensor. Therefore, both optically assisted magnetic recording and optically assisted reproduction can be performed using a single near-field light whose source is the constriction. Therefore, an ultra-compact and lightweight magnetic recording / reproducing head can be realized at a low manufacturing cost. It is also excellent in that only one laser light source is used. Furthermore, a large power consumption is not required as compared with that of Patent Document 2. In addition, as described above, the near-field light generating unit can be disposed in the very vicinity of the magnetic sensor, so that the magnetic field generated by the magnetic sensor is kept in a state where natural cooling of the heating area of the magnetic recording medium heated by the near-field light is extremely small. Detection is possible, and efficient light-assisted reproduction can be realized. At the same time, since it is not necessary to heat the magnetic recording medium excessively, the power consumption of the laser light source can be reduced. Furthermore, the heating area of the magnetic recording medium is reduced, and high-resolution optically assisted reproduction can be realized. In addition, the possibility of erroneous erasure of the magnetic recording medium during optically assisted reproduction is reduced, and the medium design margin is increased. Further, as described above, since the irradiation intensity of the laser beam can be reduced, the magnetic sensor is not excessively heated, and a magnetic recording / reproducing head having a high magnetic field detection capability can be provided.

  Further, the pair of magnetic shields makes it difficult for the magnetic sensor to be affected by the surrounding stray magnetic field that becomes a noise source, and enables high-precision light-assisted reproduction. In addition, even if the magnetic shield is made thick, the near-field light generation location does not leave the magnetic sensor, so it cancels out the leakage magnetic field from the adjacent bit that becomes the noise source during magnetic signal reproduction and the stray magnetic field in the device A magnetic recording / reproducing head having a high effect can be provided.

(2) In the magnetic recording / reproducing head of (1), it is preferable that a dielectric layer is formed between the recording element and the magnetic sensor. As a result, an electrical short circuit between the recording element and the magnetic sensor can be prevented, and at the same time, the recording element and the magnetic sensor can be continuously formed on the same substrate by using a thin film forming method. Compared to the case of forming the magnetic recording / reproducing head, it is possible to realize a small and lightweight magnetic recording / reproducing head with no positional deviation and low manufacturing cost.

(3) In the magnetic recording / reproducing head of (2), the first magnetic sensor electrode layer and the second magnetic sensor electrode layer are formed so as to sandwich the magnetic sensor. More preferably, the first magnetic sensor electrode layer for energization is formed at a position such that the dielectric layer is sandwiched between the first shape layer and the local shape changing portion.

  According to the magnetic recording / reproducing head of (3), a high-efficiency electric field enhancement can be caused by the interaction between the local shape changing portion and the magnetic sensor when irradiated with laser light. High-intensity near-field light can be obtained. Therefore, since the amplified high-intensity near-field light can be irradiated onto the magnetic recording medium, high-intensity near-field light can be obtained even when the light from the laser light source is irradiated at a low output, further reducing the consumption of the laser light source. Electricity can be realized. Further, the magnetic sensor electrode layer can serve as an electrode for energizing the magnetic sensor and as a member for generating and enhancing near-field light. Accordingly, since the near-field light generation location can be arranged in the very vicinity of the magnetic sensor, efficient light-assisted reproduction is possible, and the member serving as an electrode for energizing the magnetic sensor and the near-field light are enhanced. There is an effect that the number of members can be reduced as compared with the case where the members that play a role are formed individually.

(4) In the magnetic recording / reproducing heads of the above (1) to (3), the local shape changing portion is closer to the magnetic sensor than the pair of electrodes in the narrowed portion connecting the pair of electrodes. It is preferable that it is formed in the part curved in the convex shape provided in.

  According to the magnetic recording / reproducing head of (4), it is possible to generate stronger near-field light on the protruding portion side of the local shape changing portion curved in the convex shape than on the concave portion side of the local shape changing portion. Therefore, coupled with the fact that the near-field light source and the magnetic sensor are formed close to each other, more efficient light-assisted reproduction can be performed.

(5) In the magnetic recording / reproducing head of (4), it is preferable that the maximum width of the region in the direction parallel to the surface of the magnetic recording medium of the near-field light is smaller than the radius of curvature of the protrusion. According to this, it is possible to irradiate near-field light on an extremely narrow area on the magnetic recording medium, so that higher density optically assisted magnetic recording and higher resolution optically assisted reproduction can be realized.

(6) In the magnetic recording / reproducing heads of (3) to (5) above, the distance between the local shape changing portion and the magnetic sensor electrode layer for energizing the magnetic sensor is 5 nm or more and 100 nm or less. preferable.

(7) In the magnetic recording / reproducing heads of (3) to (5) above, the distance between the local shape changing portion and the magnetic sensor electrode layer for energizing the magnetic sensor is 10 nm or more and 50 nm or less. Further preferred.

(8) In the magnetic recording / reproducing heads of (3) to (5), at least a part of the first magnetic sensor electrode layer is formed of a metal mainly composed of Au, Ag, and Al. preferable.

  According to the magnetic recording / reproducing heads of (6) to (8), the multiple interference effect of a stronger electric field between the local shape changing portion formed in the narrowed portion of the recording element and the first magnetic sensor electrode layer. Since (resonance effect) is obtained, particularly high-intensity near-field light can be obtained, and the magnetic sensor element capable of heating the recording medium more efficiently can be provided. That is, even when irradiated with a laser beam having a lower intensity, a high-intensity near-field light can be obtained, so that the power consumption of the laser light source can be further reduced. Further, as described above, since the irradiation intensity of laser light can be reduced, the magnetic sensor is not heated excessively, and a magnetic sensor element having a high magnetic field detection capability can be provided.

(9) In the magnetic recording / reproducing heads of the above (1) to (8), the magnetic sensor has a magnetization free phase in which the nonmagnetic layer is sandwiched between the nonmagnetic layer, the magnetization fixed layer, and the magnetization fixed layer. It is a spin-valve magnetoresistive element including a layer, and the magnetization free layer is preferably formed at a position closer to the recording element than the magnetization fixed layer. As a result, the heating area of the magnetic recording medium heated by the near-field light can be moved directly under the magnetization free layer of the magnetic sensor while suppressing the natural cooling of the heating area of the magnetic recording medium to a smaller level, thereby improving the efficiency of optically assisted reproduction. it can.

(10) In the magnetic recording / reproducing heads of (1) to (9), it is preferable that the recording element, the magnetic sensor, and the laser light source are formed on the same substrate. As a result, it is possible to stably irradiate the narrowed portion of the recording element without causing a positional shift between the laser light and the recording element and the magnetic sensor. Recording and optically assisted playback can be realized.

(11) In the magnetic recording / reproducing heads of the above (1) to (10), it is preferable that an acute angle is formed in the local shape changing portion. Thereby, since the size of the generated near-field light can be further reduced, more local heating can be realized.

(12) In the magnetic recording / reproducing heads of the above (1) to (11), one of the pair of magnetic shields protrudes along the opposing surface of the magnetic recording medium, and magnetic recording is performed on the pair of electrodes of the recording element. It is preferable to provide a protrusion that covers at least a part of the surface on the medium side. As a result, the distance between the pair of magnetic shields on the medium facing surface can be reduced, so that the magnetic field can be detected with higher spatial resolution.

(13) It is preferable that the magnetic recording / reproducing heads of (1) to (12) further include a light-shielding body for preventing the magnetic sensor from being irradiated with laser light. Thereby, the temperature rise of the magnetic sensor can be suppressed, and the light beam can be irradiated only in the vicinity of the constricted portion of the recording element. Thereby, efficient light-assisted reproduction using near-field light can be realized without impairing the magnetic field detection performance of the magnetic sensor.

(14) A magnetic recording / reproducing apparatus according to the present invention includes any one of the above magnetic recording / reproducing heads (1) to (13) and a magnetic recording medium on which magnetic recording / reproducing is performed by the magnetic recording / reproducing head. Yes. As a result, it is possible to provide a magnetic recording / reproducing apparatus capable of achieving the above-described magnetic recording / reproducing head and capable of high-density magnetic recording and high-resolution reproduction.

(15) In the magnetic recording / reproducing apparatus of (14), the magnetic sensor in the magnetic recording / reproducing head is disposed behind the recording element in the magnetic recording / reproducing head in the moving direction of the magnetic recording medium. It is preferable. As a result, the heating area of the magnetic recording medium can be efficiently moved directly below the magnetic sensor, and optically assisted magnetic recording and optically assisted reproduction can be efficiently realized using a single near-field light source. A magnetic recording / reproducing apparatus capable of high-density magnetic recording and high-resolution reproduction can be provided.

(16) In the magnetic information recording / reproducing method of the present invention, when magnetic information is recorded, the magnetic recording / reproducing head according to any one of claims 1 to 13 is brought close to the magnetic field on the magnetic recording medium. The magnetic recording medium is heated by irradiating the field light, and magnetic information is recorded by applying a magnetic field. When reproducing the magnetic information, the near-field light emitted from the same near-field light source as in the magnetic information recording is used. Irradiation onto the magnetic recording medium heats the magnetic recording medium to a temperature lower than that during the magnetic information recording, and reads out the magnetic information.

(17) As another aspect, in the magnetic information recording / reproducing method of the present invention, when magnetic information is recorded, the magnetic recording / reproducing head in the magnetic recording / reproducing apparatus according to claim 14 is placed close to the magnetic recording medium. The magnetic recording medium is heated by irradiating the near-field light from the field light source, and the magnetic information is applied to record the magnetic information. When reproducing the magnetic information, the same near-field light source is emitted from the same magnetic information recording. The magnetic information is read out by irradiating the near-field light onto the magnetic recording medium to heat the magnetic recording medium to a temperature lower than that during the magnetic information recording.

  According to the configurations of (16) and (17) above, highly accurate and efficient optically assisted reproduction can be realized.

<First Embodiment>
The magnetic recording / reproducing head according to the first embodiment of the present invention will be described below with reference to the drawings. 1A is a side sectional view of the magnetic recording / reproducing head according to the first embodiment of the present invention, and FIG. 1B is a medium facing surface of the magnetic recording / reproducing head of FIG. 1A (FIG. 1A). FIG. FIG. 2 is a perspective view showing a main part of the magnetic recording / reproducing head of FIG. 1, partially transparent. FIG. 3 is a plan view showing a recording element in the magnetic recording / reproducing head of FIGS. 4A and 4B are diagrams showing the magnetic sensor and the magnetic shield in the magnetic recording / reproducing head of FIGS. 1 and 2, wherein FIG. 4A is a side sectional view of the vicinity of the medium facing surface, and FIG. It is a figure which shows the lower end surface of (a).

  As shown in FIG. 1A, in a magnetic recording / reproducing head 100 according to this embodiment, a laser light source 2 and a magnetic shield 3a are formed in parallel on the slider base 1 from the side facing the magnetic recording medium. . On the magnetic shield 3a, the dielectric 4a, the recording element 5, the dielectric 4b, the magnetic sensor electrode layer 6a, the magnetic sensor 7, the magnetic sensor electrode layer 6b, and the magnetic shield 3b are laminated in this order. Further, a protective film 8 is formed on the laser light source 2 and the magnetic shield 3b. Further, bias layers 9a and 9b for applying a bias magnetic field to the magnetic sensor 7 are formed on both sides of the magnetic sensor 7 and sandwiched between the magnetic sensor electrode layers 6a and 6b and along the magnetic recording medium facing surface. Has been.

  The slider substrate 1 has a tapered portion 1a at the end for receiving the air flow generated by the movement of the magnetic recording medium and causing the magnetic recording / reproducing head 100 to float on the magnetic recording medium. On the surface of the slider 1 facing the magnetic recording medium, the air flow between the magnetic recording / reproducing head 100 and the magnetic recording medium 5 is controlled when the magnetic recording / reproducing head 100 floats on the magnetic recording medium. In order to adjust the flying height of the magnetic recording / reproducing head 100 to about 5 to 10 nm, an ABS (Air Bearing Surface) surface processing shape 10 formed in a convex shape is applied (see FIG. 1B). These tapered portion 1a and ABS surface processed shape 10 are generally used in a slider of a recording / reproducing head used in a conventional hard disk device. The magnetic recording / reproducing head 100 is used by being arranged such that the taper portion 1a side is the leading side (air inflow side) with respect to the moving direction of the magnetic recording medium.

For the slider substrate 1, a substrate selected from GaAs, GaN, and Al ₂ O ₃ is used for epitaxial growth of the laser light source 2. As a modification, the slider base 1 may be made of any material as long as the laser light source 2 can be grown thereon. Or, using common ALTIC used in the slider body of the hard disk (Al 2 O ₃ · _TiC) substrate as a slider body 1, this, may be used by bonding a substrate a laser light source 2 is epitaxially grown Absent.

The laser light source 2 is a semiconductor for easily realizing optically assisted magnetic recording and optically assisted reproduction by irradiating a part of a constricted portion 5a described later with a laser beam 11 as propagating light to generate near-field light. It is a laser light source, and a general edge emitting laser can be used. For example, a blue-violet laser using GaN having a light source wavelength of about 405 nm or a red laser using GaAs having a light source wavelength of about 600 nm to 850 nm can be used. In the case of using a blue-violet laser, for example, using a GaN or _Al 2 _{O 3} as the slider body 1, in the case of using _Al 2 _{O 3} to the substrate on which the formation of the GaN buffer layer, eg, n-type GaN contact A layer in which an n-type AlGaN clad layer, an n-type GaN guide layer, an InGaN quantum well active layer, a p-type AlGaN layer, a p-type GaN guide layer, and a p-type AlGaN clad layer are sequentially laminated can be used. In the case of using a red laser, for example, a slider substrate 1GaAs is used, on which, for example, n-type AlGaAs as an n-type cladding layer, GaAs as an active layer, and p-type AlGaAs as a p-type cladding layer are laminated. Can be used. The laser light source 2 is designed so that the position of the active layer that emits the laser light 11 is disposed immediately above the portion of the narrowed portion 5a where the laser light 11 is to be irradiated. As the laser light source 2, a surface emitting laser may be used, but when a surface emitting laser is used, it is installed on the upper surface of the slider substrate 1. 2a and 3b shown in FIG. 2 are laser light source electrodes 3a and 3b for applying a voltage to the laser light source 2, respectively.

The dielectric 4a is used for electrical insulation between the magnetic shield 3a and the recording element 5, and a material having a high resistivity is used. _{Specifically,} there can be used _{SiO 2, Al 2 O 3,} SiN, a material such as AlN.

The dielectric 4b has a role of transmitting the laser light 11 on the optical axis of the laser light 11 from the laser light source 2 to the recording element 5, an interface with the recording element 5 in the vicinity of the medium facing surface, and a magnetic sensor. This is for generating surface plasmons at the interface with the electrode layer 6a. This makes it easy to design the magnetic recording / reproducing head 100 when adopting the optically assisted magnetic recording / reproducing method, and obtains high-intensity near-field light 12. The dielectric 4b, high transmittance, small dielectric material having a refractive index of _{(SiO 2, Al 2 O 3} , SiN, AlN, GaN, or the like MgF ₂₎ is used. Further, as a modification, in place of the dielectric 4b, the recording element 5 is irradiated so that the laser light 11 can be irradiated more efficiently until the recording element 5 is irradiated with the laser light 11. A waveguide may be used.

  The recording element 5 includes a constricted portion 5a capable of generating both the near-field light 12 and a recording magnetic field, and a pair of electrodes 5b connected by the constricted portion 5a, and includes Au, Ag, Al, and Cu. It is made of a nonmagnetic material having conductivity. The narrowed portion 5a is formed in a substantially semicircular shape having a protruding portion 13 and a recessed portion 14 that protrude toward the magnetic sensor 7 relative to the electrode 5b, and is a fine wire that is narrower than the electrode 5b. The electrode 5b is a conductor portion for supplying a current to the narrowed portion 5a, and has a larger cross-sectional area and a very small electric resistance than the narrowed portion 5a.

  The current flowing through the constriction 5a generates a magnetic field of about H = I / L (H: magnetic field, I: current, L: length of the path surrounding the current path) according to Ampere's right-handed screw law. For example, when the thickness and width of the constriction part are formed in a shape of 200 nm and a current of 50 mA is passed, a magnetic field of about 63 kA / m can be obtained. The narrowed portion 5a is simultaneously formed on the optical axis of the laser beam 11 and functions as a near-field generation source that generates the near-field light 12 when irradiated with the laser beam 11. The near-field light referred to here represents local plasmon and surface plasmon, and when a minute structure (projection or depression shape, shape change represented by an opening) having a size smaller than the wavelength of the laser beam 11 exists, Electric field concentration occurs in the microstructure, and occurs near the surface pole of the microstructure. In addition, the microstructure described here does not represent the entire narrowed portion 5a, but a local shape change smaller than the wavelength of the laser beam 11 existing in the narrowed portion 5a (for example, a protrusion at the tip of the narrowed portion 5a shown in FIG. 2). Part 13 and depression 14). For this reason, the entire narrowed portion 5a is not necessarily formed to be smaller than the wavelength of the laser beam 11, and it is sufficient if the narrowed portion 5a has a shape change represented by local protrusions and depressions.

  As the recording element 5, for example, an electromagnetic field generating element for optically assisted magnetic recording having both a function of generating near-field light and a function of generating a magnetic field has been proposed (for example, Japanese Patent Application Laid-Open No. 2004-2004). No. 303299). The electromagnetic field generating element disclosed in this document irradiates a narrow portion made of a metal having high electrical conductivity such as Au, Pt, Ag, and Cu with laser light, and excites surface plasmons in the protrusion shape of the narrow portion. By doing so, near-field light is generated. At the same time, a current is passed through the constricted portion, and this is used as a magnetic field generating source to generate a recording magnetic field from the constricted portion. If such an electromagnetic field generating element is used for a recording element, near-field light and a recording magnetic field can be generated from substantially the same location, and therefore suitable as a recording element for optically assisted magnetic recording using near-field light. Is.

  As the material of the recording element 5, a material that can efficiently propagate plasmons to the light beam 5 irradiated from the semiconductor laser near the visible light wavelength is used. Specifically, Au, Ag, Al, or an alloy material mainly composed of these is used. When a material mainly composed of Au is used for the recording element 5, a semiconductor laser with a wavelength of about 600 nm to 1 μm is used as a light source, and when a material mainly composed of Ag and Al is used, a short wavelength semiconductor laser of 600 nm or less is used. Use.

  The magnetic sensor 7 is a magnetoresistive effect element that allows a current to flow in the film thickness direction. Specifically, as shown in FIG. 4A, the magnetic sensor 7 is a stacked body in which a magnetization free layer 7a, a nonmagnetic intermediate layer 7b, and a magnetization fixed layer 7c are sequentially stacked. Then, magnetic sensor electrode layers 6a and 6b for allowing current to flow to the stacked body are formed so as to sandwich the magnetic sensor 7 from both sides in the stacking direction. As shown in FIG. 4B, the medium facing surface of the magnetic sensor 7 is formed in a film shape so as to cover other than the central portions of the magnetization free layer 7a, nonmagnetic intermediate layer 7b, and magnetization fixed layer 7c. A pair of formed nonmagnetic layers 15a and 15b, and bias layers 9a and 9b formed on the nonmagnetic layers 15a and 15b, respectively, are provided.

  The magnetization free layer 7a is a layer for detecting a magnetic field from a magnetic bit recorded on the magnetic recording medium 5, and a material having a high magnetic permeability is suitable. For example, a structure in which Fe, NiFe, NiFeTa, CoFe, CoFeB, GdCo, GdFeCo, HoFeCo, FeRh, FeRhIr, a material containing these, and a plurality of layers made of these materials are stacked can be used.

The nonmagnetic intermediate layer 7b serves to disconnect the magnetic coupling between the magnetization free layer 7a and the magnetization fixed layer 7c, and when the nonmagnetic intermediate layer 7b is formed of a conductor typified by Cu, the magnetic The sensor 7 is a CPP-GMR (Current Perpendicular to Plane-Giant Magneto-resistive) element. When the nonmagnetic intermediate layer 7b is formed of an insulator typified by Al ₂ O ₃ or MgO, a TMR (Tunneling Magneto- resistive) element.

  Although not illustrated, the magnetization fixed layer 7c is a layer configured by a laminated structure of a ferromagnetic material and an antiferromagnetic material, and the magnetization direction of the ferromagnetic material is fixed in one direction by the antiferromagnetic material. For example, Fe, CoFe, and CoFeB can be used for the ferromagnetic layer, and for example, MnPt, MnIr, and MnFe can be used for the antiferromagnetic layer. For the purpose of reducing the magnetic field generated from the magnetization fixed layer 7c itself, the magnetization fixed layer 7c may be a nonmagnetic material layer having a thickness of about 1 nm or less in the middle of the ferromagnetic layer. For the nonmagnetic layer, for example, Ru or Pt can be used.

  Since the magnetic sensor 7 has the above-described configuration, the magnetization direction of the magnetization free layer 7a changes depending on the direction of the leakage magnetic field generated from the magnetic bit recorded on the magnetic recording medium 5, and the magnetization free layer. The amount of current flowing through the element varies depending on whether the magnetization directions of 7a and the magnetization fixed layer 7c are parallel or antiparallel to each other. Using this characteristic, the magnetic recording information of the magnetic recording medium 5 can be read. As a modification of the magnetic sensor 7, a Hall effect element can be used.

The nonmagnetic layers 15a and 15b are made of Al ₂ O ₃ or SiO ₂ . The bias layers 9a and 9b are for aligning the magnetization direction of the magnetization free layer 7a, and are made of a ferromagnetic material such as CoPt, CoFePt, CoPtB, CoCrPt, and CoCrPtB.

  The magnetic sensor electrode layers 6a and 6b are made of a highly conductive metal material. For example, Au, Ag, Al, Pt, Ru, Ta, and materials containing these can be used. In particular, the magnetic sensor electrode layer 6a facing the recording element 5 through the dielectric 4b plays a role of enhancing surface plasmon due to the multiple interference effect with the recording element 5, and therefore, near the visible light wavelength. A material that can efficiently propagate plasmons to the light beam 5 irradiated from the semiconductor laser is desirable. Specifically, it is desirable to use Au, Ag, Al, or an alloy material mainly composed of these. When a material mainly composed of Au is used for the magnetic sensor electrode layer 6a, a semiconductor laser having a wavelength of about 600 nm to 1 μm is used as a light source, and when a material mainly composed of Ag and Al is used, a short wavelength of 600 nm or less. A semiconductor laser is used.

  The distance between the protrusion 13 and the magnetic sensor electrode layer 6a is formed to be 5 nm to 100 nm (preferably 10 nm to 50 nm). Thereby, a stronger multiple interference effect (resonance effect) of the electric field is obtained between the protrusion 13 formed in the narrowed portion 5a of the recording element 5 and the magnetic sensor electrode layer 6a. There is an effect that it is possible to provide the magnetic sensor element 8 which can obtain near-field light and can heat the magnetic recording medium more efficiently. That is, even when irradiated with a laser beam having a lower intensity, a high-intensity near-field light can be obtained, so that the power consumption of the laser light source can be further reduced. Further, as described above, since the irradiation intensity of the laser beam can be reduced, the magnetic sensor 7 is not heated excessively, and a magnetic sensor element having a high magnetic field detection capability can be provided.

  The magnetic shields 3 a and 3 b are magnetic shields for canceling the influence of the magnetic field existing around the magnetic sensor 7, and are formed so as to sandwich the magnetic sensor 7 and the recording element 5. Further, the magnetic shields 3a and 3b are formed so as to be exposed on the surface facing the magnetic recording medium 5 in the magnetic recording / reproducing head 100 shown in FIG. The magnetic shields 3a and 3b have a thickness of about 100 nm to 3 μm, and a material having a magnetic shielding effect such as NiFe is used. Such magnetic shields 3a and 3b can reliably reduce the influence of the surrounding stray magnetic field that becomes a noise source, and also have a heat dissipation effect.

Although Al ₂ O ₃ is used for the protective film 8, a dielectric material such as SiO ₂ , SiN, AlN, or GaN may be used.

  Next, a method for manufacturing the magnetic recording / reproducing head 100 will be specifically described with reference to FIGS. FIG. 5 is a diagram showing the manufacturing process of the magnetic recording / reproducing head 100 in order. FIG. 6 is a diagram showing the manufacturing process of the recording element 5 in order.

  First, as shown in FIG. 5A, a laser light source 2 is formed on a slider substrate 1 made of n-type GaAs using an MOCVD apparatus. Here, for the laser light source 2, a GaAlAs semiconductor laser having a wavelength of about 750 to 850 nm, a GaAlInP semiconductor laser having a wavelength of about 620 to 680 nm, a GaN semiconductor laser having a wavelength of about 405 nm, or the like may be used. In this example, a GaAlInP semiconductor laser is used.

  First, on the slider substrate 1 made of n-type GaAs, n-type GaInP is formed as a buffer layer with a film thickness of 300 nm. Subsequently, the n-type AlGaInP clad layer is formed with a film thickness of 1 μm, and the active layer made of GaInP is formed with a film thickness. A p-type AlGaInP cladding layer is formed to a thickness of 1.2 μm at 60 nm. A part of the p-type AlGaInP cladding layer is etched to form a striped ridge structure, and then a cap layer made of p-type GaInP with a thickness of 200 nm is formed on the ridge structure. In a region other than the ridge structure, an n-type GaAs block layer having a thickness of 700 nm is formed, and a contact layer made of p-type GaAs and a p-type electrode layer 3a made of a Zn / Au layer are formed thereon. On the other hand, Ge / Au is formed on the n-type GaAs slider substrate 1, and this is used as the n-type electrode 3b. These all use known semiconductor laser structures and manufacturing methods.

  Subsequently, the magnetic shield 3a was formed of NiFe adjacent to the laser light source 2 (see FIG. 5B). The film thickness of the magnetic shield 3a at this time is 1 μm.

  Subsequently, after forming the dielectric 4a with a film thickness of 10 nm on the magnetic shield 3a in FIG. 5B, the recording element 5 is formed on the dielectric 4a as shown in FIG. 5C.

  Here, a method of forming the recording element 5 will be described with reference to FIG. As shown in FIG. 6A, first, an Au layer 6 serving as the recording element 5 is formed with a film thickness of 400 nm on the dielectric 4a laminated on the magnetic shield 3a.

  Subsequently, as shown in FIG. 6B, the central portion is etched with a width of 100 nm, and the substantially central portion of the Au layer 6 is removed.

  Subsequently, as shown in FIG. 6C, the dielectric 4a is embedded so that a convex portion is formed in the etched portion, and the upper portion of the dielectric 4a is etched to be patterned into an inverted U shape.

  Subsequently, after forming an Au layer with a film thickness of 200 nm as shown in FIG. 6D, unnecessary portions are removed by etching as shown in FIG. 6E, and the constricted portion 5a and the electrode 5b are formed. The recording element 5 is formed. At this time, the narrowed portion 5a is etched with a width of 200 nm in the Z direction from the medium facing surface to form the narrowed portion 5a having a shape as shown in FIG.

  Subsequently, a dielectric 4b is formed on the recording element 5 as shown in FIG. 5D, and a magnetic sensor electrode layer 6a made of Au is further formed on the dielectric 4b as shown in FIG. 5E. The film is formed with a thickness of 50 nm, and the magnetic sensor 7 made of a magnetoresistive effect element and the magnetic sensor electrode layer 6b made of Au are formed in order of 50 nm in thickness.

For the magnetization free layer 7a included in the magnetic sensor 7, a laminated film of NiFe having a thickness of 5 nm and CoFeB having a thickness of 3 nm is used. The nonmagnetic intermediate layer 7b is made of MgO, which is an insulator, with a thickness of 1 nm. The magnetization fixed layer 7c has a thickness of 3 nm of CoFeB, a thickness of 0.85 nm of Ru, a thickness of 3 nm of CoFeB, and a thickness of 15 nm. MnPt is laminated in order. The stacking order from the slider substrate 1 side is the magnetization free layer 7a, the nonmagnetic intermediate layer 7b, and the magnetization fixed layer 7c. By laminating in this order, the magnetization free layer 7 a for detecting the magnetic field from the magnetic recording medium can be arranged at a position closer to the near-field light 12. Then, a pair of nonmagnetic layers 15a and 15b made of Al ₂ O ₃ are formed along the Y direction of the magnetization free layer 7a with the magnetization free layer 7a exposed, and then a pair of bias layers is formed thereon. 9a and 9b are formed of CoCrPtB, respectively. The lengths in the Z direction of the magnetic sensor electrode layers 6a and 6b are 200 nm, and the lengths in the Z direction of the magnetic sensor 7, the nonmagnetic layers 15a and 15b, and the bias layers 9a and 9b are all 100 nm. .

  Subsequently, a region other than the laser light source 2 and the magnetic sensor electrode layer 6b is filled with the dielectric 4b.

  Then, as shown in FIG. 5F, a magnetic shield 3b made of NiFe having a thickness of 1 μm is formed on the dielectric 4b and the magnetic sensor electrode layer 6b, and then protected on the laser light source 2 and the magnetic shield 3b. The layer film 10 is formed to complete the magnetic recording / reproducing head 100.

Next, the recording operation of the magnetic recording / reproducing head 100 will be described. The laser light source 2 is energized, the laser light 11 is emitted, and the constricted portion 5 a of the recording element 5 is irradiated. As a result, electric field concentration occurs in the protrusion 13, surface plasmon is generated, and the electric field intensity is amplified by interaction (multiple interference) with the magnetic sensor electrode layer 6 a, which is larger than the wavelength of the laser light source 2. High-intensity near-field light 12 having a small spot diameter (reachable range from the protrusion 13) is generated. At the same time, a current is supplied to the recording element 5 and the current is constricted in the constricted portion 5a to generate a recording magnetic field. The magnetic recording medium near-field light 12 is irradiated, the recording magnetic field coercivity H _c of the recording layer is heated locally by the magnetic body is generated in temporarily smaller (stenosis 5a included in the magnetic recording medium Also smaller). At the same time, the recording magnetic field generated from the narrowed portion 5a changes the magnetization direction of the recording layer, and recording is performed. Note that the direction of the recording magnetic field can be determined by reversing the direction of the current applied to the recording element 5. After recording on the recording layer, the energization of the laser light source 2 is stopped and the irradiation of the laser light 11 is stopped, or the energization power of the laser light source 2 is reduced to reduce the irradiation power of the laser light 11. Accordingly, the recording layer coercivity H _c of the cooled magnetic body recovers, the magnetization information is stably maintained.

Next, the operation during reproduction of the magnetic recording / reproducing head 100 will be described. First, the laser light source 2 is energized, the laser light 11 is generated with a weaker power than during recording, and this is irradiated onto the constricted portion 5 a of the recording element 5. As a result, as in the recording, near-field light 12 is generated in which the electric field strength is amplified by the interaction (multiple interference) with the magnetic sensor electrode layer 6a at the protrusion 13, but the power of the laser light 11 is increased. In proportion to this, the energy density of the near-field light 12 is also weaker than that during recording. At the time of reproduction, the recording element 5 is not energized so that the magnetic field from the constricted portion 5a is not generated. When the near-field light 12 is irradiated onto the magnetic recording medium, the recording layer of the magnetic recording medium is locally heated, and a leakage magnetic field is generated only from the magnetic bit at the local heating location. At this time, the energy density of the near-field light 12 is lower than that during recording, and, since no addition of recording magnetic field, the coercive force H _c of the recording layer is not reducing as causing magnetization reversal, stable The recording state is maintained. The heating region on the magnetic recording medium locally heated by the near-field light 12 is directly below the magnetic sensor 7 formed on the rear end side in the medium moving direction with respect to the recording element 5 as the magnetic recording medium moves. Moving. Here, the energy distribution of the near-field light 12 applied to the magnetic recording medium shows a Gaussian distribution, but the heat distribution on the magnetic recording medium heated by the near-field light 12 indicates that the magnetic recording medium is X in FIG. Due to the movement in the direction, the center position of the heat distribution shifts in the positive X direction. For this reason, the magnetic sensor 7 is locally heated by disposing the magnetic sensor 7 on the rear end side (X is a positive direction) in the medium movement direction from the generation point (protrusion 13) of the near-field light 12 that is the heating source. The recorded information on the recording medium can be read efficiently. Further, the protrusion 13 that generates the near-field light 12 protrudes toward the magnetic sensor 7, and the distance between the near-field light generation location and the magnetic sensor 7 (specifically, the magnetization free layer 7 a) is close. Yes. Thereby, the leakage magnetic field can be detected by the magnetic sensor 7 before the temperature of the heating area of the magnetic recording medium is lowered. The magnetic sensor 7 can detect (reproduce) the recorded information by detecting the leakage magnetic field from the local heating region and converting it to an electric signal.

  If the optically assisted reproduction method as described above is used, a strong leakage magnetic field is generated only from the recording layer heating portion of the magnetic recording medium, and the heating area size determines the spatial resolution of reproduction. That is, even when the magnetic sensor 7 having a size larger than the bit size to be reproduced is used, reproduction resolution exceeding the spatial resolution of the magnetic sensor 7 can be realized by performing local heating.

  According to the magnetic recording / reproducing head 100 of the present embodiment, a high-intensity near-field is obtained by the electric field enhancement effect between the local shape-changing protrusion 13 serving as a near-field light generation source and the magnetic sensor electrode layer 6a. Light 12 is obtained. For this reason, the generation position of the near-field light 12 and the magnetic sensor 7 are close to each other, and both optical-assisted magnetic recording and optical-assisted reproduction are performed using high-intensity near-field light from which the protrusions 13 are generated. Is possible. Therefore, it is possible to realize a magnetic recording / reproducing head 100 which is low in manufacturing cost, ultra-compact and lightweight. Moreover, it is also excellent in that only one laser light source 2 is used. Furthermore, a large power consumption is not required as compared with that of Patent Document 2. Further, the magnetic shields 3a and 3b make the magnetic sensor 7 less susceptible to the surrounding stray magnetic field that becomes a noise source, and reproduction with higher accuracy is possible than when the magnetic shields 3a and 3b are not provided.

  Further, the protrusion 13 is formed in a convexly curved portion provided in a position closer to the magnetic sensor 7 than the pair of electrodes 5b in the narrowed portion 5a, and a near-field light source (protrusion 13). ) And the magnetic sensor 7 are formed close to each other, and more efficient light-assisted reproduction is possible than when the protrusion 13 is formed in a portion other than the convex curved portion.

  Furthermore, the magnetic sensor 7 is a spin-valve magnetoresistive effect element, and since the magnetization free layer 7a is formed at a position closer to the recording element 5 than the magnetization fixed layer 7c, the efficiency of optically assisted reproduction can be improved. .

  In addition, since it is possible to obtain high-intensity near-field light 12 that is locally enhanced at a location where the distance from the magnetic sensor electrode 8a is small, the size of the generated near-field light 12 is determined by the curvature of the protrusion 13. It can be made smaller than the radius, and local heating can be realized. As a result, the resolution of optical assist reproduction can be improved.

  In the magnetic recording / reproducing head 100, since the recording element 5, the magnetic sensor 7, and the laser light source 2 are continuously formed on the same substrate by using a thin film forming method, the laser beam 11, the recording element 5, and High-precision optically assisted magnetic recording and optically assisted reproduction can be realized without causing any positional deviation from the magnetic sensor 7. Further, since there is no need to separately form and combine the recording element and the magnetic sensor element, the number of members can be reduced, and the manufacturing process can be simplified. Further, since the recording element 5 is a non-magnetic material and does not generate a magnetic field except when energized, it does not affect the reproduction sensitivity of the magnetic sensor 7 during reproduction, and highly sensitive optically assisted reproduction is possible. is there. For this reason, the recording element 5 can be formed between the magnetic shields 3a and 3b.

<Modification of First Embodiment>
Next, a modification of the magnetic head 100 of the first embodiment will be described. FIG. 7 is a diagram showing a main part of a magnetic recording / reproducing head according to a modification of the first embodiment, and is a partially transparent perspective view. In addition, the code | symbol 21-52 is attached | subjected to the part similar to the codes | symbols 1-12 of 1st Embodiment, and the description may be abbreviate | omitted.

As shown in FIG. 7, in the magnetic recording / reproducing head 200 of the present modification, the magnetic shield 23a protrudes along the facing surface of the magnetic recording medium, and the pair of electrodes 25b of the recording element 25 is interposed via the dielectric 24a. It is different from the magnetic head 100 of the first embodiment in a point provided with a protruding portion 25a ₁ that covers the surface of the magnetic recording medium side. Although not shown, the configuration around the magnetic sensor 27 is the same as the configuration around the magnetic sensor 7 of the first embodiment (configuration of the bias layers 9a and 9b and the nonmagnetic layers 15a and 15b).

  A method of manufacturing the magnetic recording / reproducing head 200 of this modification will be described with reference to FIG. FIG. 8 is a diagram sequentially illustrating the manufacturing process of the magnetic recording / reproducing head 200 of this modification.

  First, the laser light source 22 is formed on the slider base 21 by the same method as in the first embodiment, and then the magnetic shield 23a is formed of NiFe adjacent to the laser light source 22 (see FIG. 8A). . At this time, the film thickness of the magnetic shield 23a is 1.2 μm.

Subsequently, in the magnetic shield 23a of FIG. 8A, a width of 100 nm is left in the Z direction from the surface facing the magnetic recording medium so as to have a stepped shape at the end on the medium facing surface side, and the remaining portion sharpener 200nm by etching to form a protruding portion 27a ₁ (see Figure 8 (b)).

  Subsequently, after forming a dielectric 24a with a film thickness of 10 nm on the etched part in FIG. 8B, the recording element 25 made of Au has an electrode shape as shown in the perspective view of FIG. (Substantially U-shaped) (see FIG. 8C).

Subsequently, a dielectric 24b made of Al ₂ O ₃ is formed on the recording element 25 (see FIG. 8D). Subsequently, similarly to the first embodiment, the magnetic sensor electrode layer 26a and the magnetic sensor 27 are formed. Then, the magnetic sensor electrode layer 26b, the magnetic shield 23b, and the protective film 28 are sequentially formed (see FIGS. 8E and 8F) to complete the magnetic recording / reproducing head 200.

  According to this modification, in addition to the same effects as those of the first embodiment, a part of the magnetic shield 23a protrudes below the electrode 26b of the recording element 25 (distance between the magnetic shields 23a and 23b). Therefore, the gap between the magnetic shield 23a and the magnetic shield 23b can be reduced. As a result, it is possible to provide the magnetic recording / reproducing head 200 that is less affected by the stray magnetic field from the outside and the leakage magnetic field generated from the peripheral bits of the bit to be reproduced. Thereby, at the time of optical assist reproduction, the recording bit of the magnetic recording medium heated by the near-field light reaches under the magnetic sensor 27 more efficiently, and the magnetic recording / reproduction is strong against external magnetic field noise and magnetic noise from peripheral bits. The head 200 can be provided. Therefore, optically assisted reproduction with higher spatial resolution can be realized.

Second Embodiment
A magnetic recording / reproducing head according to a second embodiment of the invention will be described with reference to FIG. FIG. 9 is a schematic side view (XZ plane schematic diagram) of the magnetic recording / reproducing head according to the second embodiment. In addition, the code | symbols 41-52 are attached | subjected in order to the part similar to the codes | symbols 1-12 of 1st Embodiment, and the description may be abbreviate | omitted.

  In the magnetic recording / reproducing head 300 according to the present embodiment, a light shielding body 56 for shielding a part of the laser beam 51 irradiated to the recording element 45, more specifically, a region irradiated to the magnetic sensor 47 is provided. It differs from the magnetic head 100 of the first embodiment in that it is formed. Specifically, as shown in FIG. 9, the light shield 56 is formed in the vicinity of the irradiation side of the laser beam 51 of the magnetic sensor 47, and is formed with a thickness that shields the laser beam 51 irradiated to the magnetic sensor 47. ing. Although not shown, the configuration around the magnetic sensor 47 is the same as the configuration around the magnetic sensor 7 of the first embodiment (configuration of the bias layers 9a and 9b and the nonmagnetic layers 15a and 15b).

  The material used for the light shielding body 56 may be any material having a low transmittance, and is not particularly limited. However, Au, Ag, Al, Cu, Pt, Ru, Ta, and alloys thereof can be used. Among these, if a material such as Au, Au, or Cu having a high thermal conductivity is used, an effect as a heat radiator can also be achieved.

  The thickness of the light shielding body 56 in the Z direction is not particularly limited as long as it can shield the laser beam 51, and is formed to a thickness of 50 nm or more, for example. Further, it is formed with a width larger than the spot diameter of the laser beam 51 in the depth direction (Y direction) of the drawing. In order to obtain a high heat dissipation effect, it may be formed up to the width of both ends of the slider base 41 in the depth direction (Y direction) of the drawing. If the light shielding body 56 is formed in this way, the temperature rise of the magnetic sensor 47 can be suppressed, and the laser beam 51 can be irradiated only in the vicinity of the recording element 45 that is a near-field light generation source.

  According to the magnetic recording / reproducing head 300 of this embodiment, the same effects as those of the first embodiment can be obtained, and efficient optically assisted reproduction using near-field light can be performed without impairing the magnetic field detection performance of the magnetic sensor 47. realizable.

<Third Embodiment>
Next, a magnetic recording / reproducing apparatus according to the third embodiment of the present invention will be described with reference to FIG. FIG. 10 is a schematic configuration diagram of a magnetic recording / reproducing apparatus according to the third embodiment of the present invention. Here, a case where the same magnetic recording / reproducing head and magnetic recording medium as those in the first embodiment are used will be described as an example.

  A magnetic recording / reproducing apparatus 400 according to this embodiment includes a magnetic recording / reproducing head 401, a disk-shaped magnetic recording medium 402, a spindle 403 for rotationally driving the magnetic recording medium 402, and a magnetic recording / reproducing head, as in the first embodiment. A suspension arm 404 for supporting and fixing 401, a voice coil motor 405 for driving the suspension arm 404 on the magnetic recording medium 401, and a control circuit 406 for controlling them. The control circuit 406 includes a rotational drive control device 407 that controls the rotational drive of the spindle 403, a signal processing device 408 that exchanges signals with the magnetic recording / reproducing head 401, and an output of a light source formed in the magnetic recording / reproducing head 401. An output control device 409 for controlling and a memory device 410 for storing the read information are included. As the spindle 403 rotates, the magnetic recording medium 402 rotates and generates an air flow. Using the generated air flow, the magnetic recording / reproducing head 401 floats on the magnetic recording medium 402 at a height of about 10 nm and performs recording / reproducing on the magnetic recording medium 402. These structures are used for a known hard disk except for the magnetic recording / reproducing head 401.

  The rotational speed of the spindle 403 is not particularly limited as long as it can stably perform recording and reproduction. For example, a rotational speed of 1800 rpm to 7200 rpm can be used.

  The magnetic sensor in the magnetic recording / reproducing head 401 is disposed on the rear end side in the medium moving direction from the position of the recording element. With this arrangement, the heating area of the magnetic recording medium 402 can be efficiently moved directly below the magnetic sensor in the magnetic recording / reproducing head 401 during optically assisted reproduction.

  The magnetic recording medium 402 corresponds to an optically assisted reproduction system (described in Japanese Patent No. 2617025), and includes a substrate 402a made of silicon or quartz, and a recording layer 402b formed on the substrate 402a. And has. The recording layer 402b exhibits a magnetization amount larger than the magnetization amount at room temperature at a certain temperature higher than room temperature. In order to realize the magnetic recording medium 402, the recording layer 402b includes a ferrimagnetic material, a magnetic material exhibiting an antiferromagnetic-ferromagnetic transition, a laminated structure of these magnetic materials and a ferromagnetic material, or ferrimagnetic material. A layered structure between bodies and a layered structure with a magnetic body exhibiting an antiferromagnetic-ferromagnetic transition are used. Examples of the ferrimagnetic material include a ferrimagnetic material composed of a heavy rare earth metal and a 3d transition metal, such as a heavy rare earth metal selected from Tb, Dy, Gd, and Ho, and a 3d transition metal selected from Fe, Co, and Ni. A ferrimagnetic material made of can be used. For example, FeRh and FeRhIr can be used as the magnetic material exhibiting an antiferromagnetic-ferromagnetic transition. These are materials that exhibit characteristics as an antiferromagnetic material at room temperature, do not generate a leakage magnetic field, and exhibit ferromagnetism at a high temperature to generate a leakage magnetic field. The ferromagnetic material laminated with these magnetic materials is desirably a perpendicular magnetization film containing CoFeB, CoFePt, CoFePtB, FePt, FePd, CoPt, and CoPd.

An example in which TbFeCo, which is a ferrimagnetic material, is used for the recording layer 402b is as follows. In the magnetic recording medium 402, TbFeCo, which is a ferrimagnetic material, is formed as a recording layer 402b with a film thickness of 50 nm on a disk-shaped glass substrate. Here TbFeCo is to allow the photo-assisted reproduction, and the coercive force H _c is 10kOe or more at room temperature, and adjusting the composition so that the total magnetization is substantially 0. The compensation temperature. The composition is adjusted so that the Curie temperature at which the magnetization disappears is about 200 ° C. On the recording layer 402b of the magnetic recording medium 402, a C film is formed with a thickness of 5 nm for the purpose of protecting the recording layer, and a lubricant is applied and formed with a thickness of 1 nm.

  Next, the operation of the magnetic recording / reproducing apparatus 400 according to the third embodiment of the present invention will be described. When the power is turned on, the magnetic recording / reproducing head 401 floats on the magnetic recording medium 402 with a flying height of about 10 nm by the air flow generated by the rotation of the spindle 403, and is recorded on the recording layer 402 b of the magnetic recording medium 402. On the other hand, optical assist type recording / reproduction can be performed.

The recording process on the recording layer of the magnetic recording medium 402 is as follows. First, the laser light source of the magnetic recording / reproducing head 401 is energized to emit laser light, and this laser light is applied to the constricted portion of the recording element of the magnetic recording / reproducing head 401. As a result, the concentration of the electric field occurs at the protrusion of the constriction, and enhancement by multiple interference is performed between the magnetic sensor electrode layer and the spot diameter (reachable range from the protrusion) smaller than the laser light source wavelength. High-intensity near-field light is generated. At the same time, a current is supplied to the recording element of the magnetic recording / reproducing head 401, the current is confined in the constricted portion, and a recording magnetic field is generated. The recording layer 402b of the magnetic recording medium 402 near-field light is irradiated, the recording layer 402b of the magnetic recording medium 402 is the coercive force H _c of locally heated magnetic material occurs in temporarily smaller (stenosis Smaller than the recording magnetic field). At the same time, recording is performed by changing the magnetization direction of the recording layer 402b of the magnetic recording medium 402 by the recording magnetic field generated from the narrowed portion of the recording element of the magnetic recording / reproducing head 401. The direction of the recording magnetic field can be determined by reversing the direction of the current applied to the recording element of the magnetic recording / reproducing head 401. After recording on the recording layer 402b of the magnetic recording medium 402, the energization of the laser light source of the magnetic recording / reproducing head 401 is stopped to stop the irradiation of the laser light, or the laser light source of the magnetic recording / reproducing head 401 is turned on. by weakening the irradiation power of the power supply amount to reduce laser beam, the recording layer 402b of the magnetic recording medium 402 is cooled by the coercive force H _c of the magnetic material to recover, the magnetization information is stably maintained.

Next, a process for reproducing recorded information recorded by the above method will be described. When the power is turned on, first, the spindle 403 rotates to rotate the magnetic recording medium 402. Subsequently, the laser light source of the magnetic recording / reproducing head 401 is energized to generate laser light with a power lower than that during recording, and this is irradiated to the protrusions of the constricted portion of the recording element of the magnetic recording / reproducing head 401. As a result, a high-intensity near-field light amplified at the protruding portion of the magnetic recording / reproducing head 401 is generated in the same manner as during recording, but the energy density of the near-field light is proportional to the power of the laser light. It becomes about half. At this time, the output control device 409 included in the control circuit 406 adjusts the output of the light source so as to obtain good reproduction signal quality. During reproduction, the recording element of the magnetic recording / reproducing head 401 is not energized so that a magnetic field from the constricted portion is not generated. When the near-field light is irradiated onto the magnetic recording medium 402, the recording layer 402b of the magnetic recording medium 402 is locally heated, and a leakage magnetic field is generated only from the magnetic bit at the local heating location. At this time, the energy density of the near-field light is lower than that during recording, and, since no addition of recording magnetic field, the coercive force H _c of the recording layer 402b of the magnetic recording medium 402 is to reduce as causing magnetization reversal There is no stable recording state. The heating region on the magnetic recording medium 402 locally heated by near-field light is formed on the rear end side in the medium moving direction with respect to the recording element of the magnetic recording / reproducing head 401 as the magnetic recording medium 402 moves. Move directly under the sensor. The magnetic recording information is read by detecting the leakage magnetic field from the information recording area by the magnetic sensor of the magnetic recording / reproducing head 401. The magnetic sensor of the magnetic recording / reproducing head 401 detects the leakage magnetic field from the local heating region, converts this into an electric signal, and reads the recorded information. Then, the reproduction of magnetic information ends.

  According to the present embodiment, the effect of the magnetic recording / reproducing head described above can be achieved, and the heating area of the magnetic recording medium can be efficiently moved directly below the magnetic sensor, using a single near-field light source, It is possible to provide a magnetic recording / reproducing apparatus capable of efficiently realizing optically assisted magnetic recording and optically assisted reproduction and capable of high-density magnetic recording.

  In the present embodiment, the same magnetic recording / reproducing head as in the first embodiment is used. However, a modification of the first embodiment or the magnetic recording / reproducing head according to the second embodiment may be used instead.

  Next, this invention is demonstrated using an Example. In describing the magnetic recording / reproducing head having the same configuration as the magnetic recording / reproducing head 100 of the first embodiment used in each example, the magnetic recording / reproducing head 100 of the first embodiment and its parts are used instead. There are things to do.

Example 1
A magnetic recording / reproducing head according to Example 1 was manufactured in the same manner as the magnetic recording / reproducing head 100 of the first embodiment. As a laser light source in this magnetic recording / reproducing head, a laser light source capable of irradiating a laser beam 11 having a wavelength of 680 nm was used. In the magnetic recording / reproducing head 100 according to this example, the electric field strength on the facing surface of the magnetic recording medium was simulated using an FDTD (Finite Difference Time Domain) method. The result is shown in FIG. In the simulation, the intensity distribution of the laser beam 11 is a Gaussian distribution, and the spot diameter is 700 nm. The deflection direction of the incident light was the Y direction in the figure. The peak intensity of the electric field of the laser beam 11 is 1 (V / m) ^2, and the spot center position of the laser beam 11 is 50 nm on the central axis in the Y direction in FIG. 11 and above the recess 14 of the recording element 5. In the dielectric 4a (position of + mark in the figure). The distance between the tip of the protrusion 13 and the magnetic sensor electrode layer 6a was 25 nm.

As shown in FIG. 11, by irradiation with the laser beam 11, a local portion (width of about 30 nm in the track width direction) near the tip of the projection 13 of the recording element 5 is contacted with the magnetic sensor electrode layer 6a. A portion where the electric field strength was strongly amplified due to the interaction (multiple interference) appeared, and an electric field strength exceeding 5 (V / m) ² larger than the electric field peak strength of the laser beam 11 was obtained.

  The region in which the electric field strength is enhanced is a region that is much smaller than the radius of curvature of the protrusion 13, and the electric field strength obtained is similar to that of the depression 14 (near the spot center position of the laser beam and the radius of curvature also protrudes). The electric field strength is much larger than the surrounding area of (smaller).

  Such a high-intensity electric field can be confirmed only at a close distance of about several tens of nanometers or less in the medium direction (Z is a negative direction) from the tip of the protrusion 13 of the recording element 5. 12 is shown.

  In this way, the configuration in which the protrusion 13 of the recording element 5 and the magnetic sensor electrode layer 6a are opposed to each other via the dielectric layer 4a is used as the generation source of the near-field light 12, thereby making the incident laser light 11 It was confirmed that a larger electric field strength was obtained and the near-field light 12 could be generated in a very local region.

(Example 2)
As Example 2, for the same configuration as the magnetic recording / reproducing head 100 of the first embodiment, the distance between the tip of the protrusion 13 of the recording element 5 and the magnetic sensor electrode layer 6a (that is, the protrusion 13 of the recording element 5). The electric field strength change was simulated when the thickness of the dielectric 4b sandwiched between the tip and the magnetic sensor electrode layer 6a was changed. The result is shown in FIG. In FIG. 12, the horizontal axis represents the distance h between the tip of the projection 13 of the recording element 5 and the magnetic sensor electrode layer 6a, and the vertical axis represents the electric field strength at the tip of the projection 13 on the medium facing surface. The conditions other than changing the distance between the tip of the protrusion 13 of the recording element 5 and the magnetic sensor electrode layer 6a are the same as the simulation conditions of the first embodiment.

  The distance between the tip of the protrusion 13 of the recording element 5 and the magnetic sensor electrode layer 6a is such that the transmitted light component (farfield component) of the laser light 11 does not pass from the periphery of the protrusion 13 and the near-field light. From the viewpoint of bringing 12 and the magnetic sensor 7 close to each other, it is considered that the thickness is preferably about 100 nm or less. Therefore, in this example, the simulation was performed in the range where the distance between the tip of the protrusion 13 of the recording element 5 and the magnetic sensor electrode layer 6a was 100 nm or less.

As shown in FIG. 12, when the distance between the protrusion 13 tip of the recording element 5 and the magnetic sensor electrode layer 6a is reduced from 100 nm, the protrusion 13 tip of the recording element 5 and the magnetic sensor electrode layer 6a As a result of the interaction (multiple interference) occurring between the two, an effect of amplifying the electric field intensity was observed, and a large electric field intensity of 6.5 (V / m) ² was obtained at a distance of 20 nm. If the distance between the tip of the projection 13 of the recording element 5 and the electrode layer 6a for the magnetic sensor is less than 20 nm, the dielectric layer 3 becomes thin, so that surface plasmons are difficult to propagate and the electric field strength obtained is also reduced. An electric field strength greater than the peak electric field strength (1 (V / m) ² ) of the laser beam 11 was obtained at a distance of 7 nm or more. Therefore, it can be seen that the amplified near-field light 12 can be obtained by setting the distance between the tip of the protrusion 13 of the recording element 5 and the magnetic sensor electrode layer 6a in the range of about 5 nm to 100 nm. More desirably, the range of 10 nm to 50 nm is preferable because the electric field intensity amplification effect is particularly strong due to the interaction (multiple interference) between the tip of the protrusion 13 of the recording element 5 and the magnetic sensor electrode layer 6a. .

  The present invention can be changed in design without departing from the scope of the claims, and is not limited to the above-described embodiments and examples. For example, the recording element 500 shown in FIG. 13A or the recording shown in FIG. 13B instead of the recording elements 5 and 45 each having the substantially cylindrical constricted portions 5a and 45a in the first and second embodiments. As in the element 500, a recording element having a constricted portion having a substantially V-shaped column shape in cross section may be used. In the recording element 500, the protrusion 501 and the recess 502 are both formed at an acute angle with respect to the recording element 5 in the first and second embodiments. In the recording element 500, only the protrusion 601 is formed at an acute angle with respect to the recording element 5 in the first and second embodiments, and the recess 602 has the same shape as the recording element 5.

In the first and second embodiments, the magnetic recording / reproducing head in which the laser light source is formed on the slider base has been described. However, the magnetic recording / reproducing head is manufactured by attaching the slider and the substrate on which the laser light source is formed. It doesn't matter. That is, for example, a substrate made of Al ₂ O ₃ on which a laser light source is formed, GaN, or GaAs may be attached to a slider made of AlTiC (Al ₂ O ₃ .TiC). At this time, the members other than the laser light source formed on the slider may be formed on the slider or may be formed on the substrate together with the laser light source. Here, when a member other than the laser light source is formed on the substrate together with the laser light source, in order to prevent a positional shift (particularly a shift in which the facing surface with the magnetic recording medium does not match) due to the bonding between the slider and the substrate, After the slider and the substrate are bonded in advance, lapping is performed so that the surface facing the magnetic recording medium is matched between the slider and the substrate, and then a tapered portion and an ABS surface processed shape are formed on the slider, In addition, a procedure for forming a recording element, a magnetic sensor, and a laser light source may be used.

  In the first and second embodiments, the laser light source is not necessarily formed inside the magnetic recording / reproducing head, and may be outside the magnetic recording / reproducing head. For example, a laser light source may be disposed on a suspension arm that supports the magnetic recording / reproducing head, and laser light may be drawn into the magnetic recording / reproducing head using an optical waveguide.

  In the first and second embodiments, part or all of the magnetic sensor electrode layer may be formed of a high permeability material having a magnetic shielding effect. For example, it may be formed of a material containing NiFe or NiFeTa. In this way, it is possible to provide a magnetic recording / reproducing head having a higher effect of canceling out the magnetic field from the region other than the magnetic bit to be reproduced and the influence of the surrounding stray magnetic field that becomes a noise source.

  In the first and second embodiments, in the magnetic sensor, the magnetic shield may be used as an electrode without forming the magnetic sensor electrode layer. In the first and second embodiments, the magnetic recording / reproducing head of the present invention does not necessarily have to be manufactured by the manufacturing method of the present embodiment, and any structure can be used as long as the same configuration as that of the present embodiment can be obtained. Such a manufacturing method may be used. In addition, a lubricant may be applied or formed on the surface of the magnetic recording / reproducing head facing the magnetic recording medium in order to prevent damage due to contact with the magnetic recording medium.

2A is a side sectional view of the magnetic recording / reproducing head according to the first embodiment of the present invention, and FIG. 2B is a diagram showing a medium facing surface of the magnetic recording / reproducing head of FIG. It is a figure which shows the principal part of the magnetic recording / reproducing head of FIG. 1, Comprising: It is the perspective view partially transparentized. FIG. 2 is a plan view showing a recording element in the magnetic recording / reproducing head of FIG. 1. 2A and 2B are diagrams illustrating a magnetic sensor and a magnetic shield in the magnetic recording / reproducing head of FIG. 1, in which FIG. 2A is a side sectional view of a portion near a medium facing surface, and FIG. FIG. 3 is a diagram sequentially illustrating manufacturing steps of the magnetic recording / reproducing head of FIG. 1. FIG. 3 is a diagram sequentially illustrating manufacturing steps of a recording element of the magnetic recording / reproducing head of FIG. 1. It is a figure which shows the principal part of the magnetic recording / reproducing head which concerns on the modification of 1st Embodiment of this invention, Comprising: It is a perspective view partially transparentized. FIG. 8 is a diagram sequentially illustrating manufacturing steps of the magnetic recording / reproducing head of FIG. 7. It is a figure which shows the principal part of the side sectional view of the magnetic recording / reproducing head concerning 2nd Embodiment of this invention. It is a model block diagram of the magnetic recording / reproducing apparatus which concerns on 3rd Embodiment of this invention. It is a figure which shows the result of the electric field intensity | strength simulation in the medium opposing surface of the magnetic recording / reproducing head based on Example 1 of this invention. It is a graph which shows the simulation result of the magnetic sensor element which concerns on Example 2 of this invention. 6A and 6B are diagrams showing a modification of the recording element in the first and second embodiments, in which FIG. 5A is a diagram showing a recording element in which both a protrusion and a recess are formed at an acute angle, and FIG. FIG. 2 is a diagram showing a recording element in which only a sharp angle is formed.

Explanation of symbols

1, 21, 41 Slider base 1a Tapered portion 2, 22, 42 Laser light source 3a, 3b, 23a, 23b, 43a, 43b Magnetic shield 3a, 3b, 23a, 23b Laser light source electrode 4a, 4b, 24a, 24b, 44a, 44b Dielectric layer 5, 25, 45, 500, 600 Recording element 5a, 25a, 45a, 500a, 600a Narrowed portion 5b, 25b, 45b, 500b, 600b Electrode 6a, 6b, 26a, 26b, 46a, 46b For magnetic sensor Electrode layer 7, 27, 47 Magnetic sensor 7a Magnetization free layer 7b Nonmagnetic intermediate layer 7c Magnetization fixed layer 8, 28, 48 Protective film 9a, 9b Bias layer 10 ABS surface processed shape 11, 31, 51 Laser light 12, 52 Proximity Field light 13, 601, 701 Protrusion 14, 602, 702 Depression 15a, 15b Non-magnetic layer 56 Light Shield 100, 200, 300, 401 Magnetic Recording / Reproducing Head 400 Magnetic Recording / Reproducing Device 402 Magnetic Recording Medium 403 Spindle 404 Suspension Arm 405 Voice Coil Motor 406 Control Circuit 407 Rotation Drive Device 408 Signal Processing Device 409 Output Control Device 410 Memory Device

Claims (17)

While applying a recording magnetic field, the magnetic recording medium is heated using near-field light to record magnetic information on the magnetic recording medium, and the magnetic recording medium is heated using near-field light to be recorded on the magnetic recording medium. A magnetic recording / reproducing head used in an optically assisted magnetic recording / reproducing system for reproducing recorded information,
A recording element comprising a non-magnetic material, a pair of electrodes, and a conductive constriction portion electrically connected to each of the pair of electrodes;
A magnetic sensor for reproducing recorded information recorded on the magnetic recording medium,
When the constricted part is irradiated with laser light, near-field light is generated from a local shape change part formed in the constricted part, and the constricted part is generated when a current flows between the pair of electrodes. A magnetic field is generated as a source,
A magnetic recording / reproducing head, further comprising a pair of magnetic shield layers provided at positions sandwiching the narrow portion and the magnetic sensor.   The magnetic recording / reproducing head according to claim 1, wherein a dielectric layer is formed between the recording element and the magnetic sensor. A first magnetic sensor electrode layer and a second magnetic sensor electrode layer are formed so as to sandwich the magnetic sensor;
3. The magnetic recording / reproducing head according to claim 2, wherein the first magnetic sensor electrode layer is formed so that the dielectric layer is sandwiched between the first magnetic sensor electrode layer and the local shape changing portion.   The local shape changing portion is formed in a curved portion provided in a convex shape provided at a position closer to the magnetic sensor than the pair of electrodes in the constriction portion connecting the pair of electrodes. The magnetic recording / reproducing head according to claim 1.   5. The magnetic recording / reproducing head according to claim 4, wherein a maximum width of a region of the near-field light in a direction parallel to the surface of the magnetic recording medium is smaller than a radius of curvature of the protrusion.   6. The magnetic recording / reproducing head according to claim 3, wherein a distance between the local shape changing portion and the first magnetic sensor electrode layer is 5 nm or more and 100 nm or less.   6. The magnetic recording / reproducing head according to claim 3, wherein a distance between the local shape changing portion and the first magnetic sensor electrode layer is 10 nm or more and 50 nm or less.   10. The magnetic recording / reproducing method according to claim 3, wherein at least a part of the first magnetic sensor electrode layer is formed of a metal mainly composed of Au, Ag, and Al. 11. head. The magnetic sensor is a spin valve magnetoresistive element including a nonmagnetic layer, a magnetization fixed layer, and a magnetization free layer sandwiching the nonmagnetic layer between the magnetization fixed layer,
The magnetic recording / reproducing head according to claim 1, wherein the magnetization free layer is formed closer to the recording element than the magnetization fixed layer.   10. The magnetic recording / reproducing head according to claim 1, wherein the recording element, the magnetic sensor, and the laser light source are formed on the same substrate.   The magnetic recording / reproducing head according to claim 1, wherein an acute angle is formed in the local shape changing portion.   One of the pair of magnetic shields includes a protrusion that protrudes along the opposing surface of the magnetic recording medium and covers at least a part of the surface on the magnetic recording medium side of the pair of electrodes of the recording element. The magnetic recording / reproducing head according to claim 1, wherein:   The magnetic recording / reproducing head according to claim 1, further comprising a light blocking body for preventing the magnetic sensor from being irradiated with laser light. A magnetic recording / reproducing head according to any one of claims 1 to 13,
A magnetic recording / reproducing apparatus comprising: a magnetic recording medium on which magnetic recording / reproducing is performed by the magnetic recording / reproducing head.   15. The magnetic recording / reproducing apparatus according to claim 14, wherein the magnetic sensor in the magnetic recording / reproducing head is disposed behind the recording element in the magnetic recording / reproducing head in the moving direction of the magnetic recording medium. . When recording magnetic information, the magnetic recording medium is heated by irradiating the near-field light from the near-field light source of the magnetic recording / reproducing head according to any one of claims 1 to 13 on the magnetic recording medium. Recording magnetic information by applying a magnetic field,
When reproducing magnetic information, the magnetic recording medium is irradiated with near-field light emitted from the same near-field light source as in the magnetic information recording to heat the magnetic recording medium to a temperature lower than that during the magnetic information recording. And reading out the magnetic information. 16. When recording magnetic information, the magnetic recording medium is heated and irradiated with a near-field light from a near-field light source of a magnetic recording / reproducing head in the magnetic recording / reproducing apparatus according to claim 14 or 15 on the magnetic recording medium. To record magnetic information,
When reproducing magnetic information, the magnetic recording medium is irradiated with near-field light emitted from the same near-field light source as in the magnetic information recording to heat the magnetic recording medium to a temperature lower than that during the magnetic information recording. And reading out the magnetic information.