Heat-assisted magnetic recording head and magnetic recording method

Abstract

The invention provides a heat-assisted magnetic recording head and a magnetic recording method, which are used for changing the magnetic moment direction of a magnetic domain in a magnetic storage medium. The heat-assisted magnetic recording head comprises a magnetic recording element, a heat insulation part and a heating assembly, wherein the magnetic recording element is used for generating a recording magnetic field; the magnetic recording element includes a recording pole applying a recording magnetic field; the heat insulation part is arranged on the magnetic recording element; the heating assembly is arranged on the heat insulation piece. Wherein the heating assembly comprises a heating element and a carbon nanotube structure; the heating element is used for generating heat; a carbon nanotube structure; one end of the carbon nanotube structure is connected with the heating element and is used for conducting heat generated by the heating element; wherein the carbon nano tube structure comprises a single carbon nano tube, and a first end part, far away from the heating element, of the single carbon nano tube is a free end and is used for heating a single magnetic domain in the magnetic storage medium. The heat-assisted magnetic recording head can effectively improve the storage density of the magnetic storage medium; the structure is simple, the manufacturing cost is low, and the magnetic material cannot be damaged.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic disk drives, and in particular to a thermally assisted magnetic recording head and a magnetic recording method. Background Art

[0002] As disk drive recording densities increase, the size of magnetic domains in magnetic storage media is shrinking. However, as the size of the magnetic domains decreases, their coercivity also decreases, causing the magnetic moment of the domains to become unstable. Even temperature disturbances can cause the direction of the magnetic moment to flip, increasing the risk of data loss in the magnetic storage media. To address this issue, magnetic storage materials with greater coercivity can be used to enhance the stability of the magnetic domains. However, this leads to another problem: the increased coercivity of the magnetic storage material makes it more difficult to record data through the magnetic field, resulting in poor data recording performance.

[0003] To address this issue, a heat-assisted magnetic recording method has been proposed. This method uses a heat-assisted magnetic recording head to record data on a magnetic storage medium with a high coercivity. This method records data by transiently heating the magnetic domains of the medium where the data is to be recorded, thereby raising their temperature. Because the coercivity of the magnetic domains decreases with increasing temperature, data can be recorded on the magnetic storage medium even with a very weak magnetic field. After data recording, the temperature of the magnetic domains in the medium where the data is already recorded decreases, increasing their coercivity and achieving stable storage.

[0004] However, in the heat-assisted magnetic recording method, the laser heating method of the magnetic domain is difficult to heat the smaller magnetic domains due to the large laser spot, which is not conducive to improving the storage density of the magnetic storage medium. Summary of the Invention

[0005] The thermally assisted magnetic recording head and magnetic recording method provided in the present application are intended to solve the problem that existing thermally assisted magnetic recording heads have difficulty heating smaller magnetic domains, which is not conducive to improving the storage density of magnetic storage media.

[0006] To solve the above technical problems, the present application adopts a technical solution: providing a thermally assisted magnetic recording head for changing the magnetic moment direction of magnetic domains in a magnetic storage medium; comprising: A magnetic recording element for generating a recording magnetic field; the magnetic recording element includes a recording pole for applying the recording magnetic field; a heat insulating member disposed on the magnetic recording element; A heating assembly is provided on the thermal insulation member; the heating assembly comprises: A heating element, used to generate heat; A carbon nanotube structure; one end of the carbon nanotube structure is connected to the heating element for conducting heat generated by the heating element; The carbon nanotube structure includes a single carbon nanotube, and the first end of the single carbon nanotube away from the heating element is a free end, which is used to heat the single magnetic domain in the magnetic storage medium.

[0007] In a specific embodiment, the heat generating element is a light-to-heat conversion layer; the light-to-heat conversion layer is configured to generate heat under light; or, The heating element is a non-magnetic metal heating circuit; the non-magnetic metal heating circuit is configured to generate heat when powered on.

[0008] In a specific embodiment, the thermal insulation member is a thermal insulation layer, the thermal insulation layer is disposed on the surface of the recording electrode, and the carbon nanotube structure is disposed on the surface of the thermal insulation layer away from the recording electrode; The first end of the recording electrode away from the heating element is a free end; the first end of the single carbon nanotube is flush with the first end of the recording electrode.

[0009] In a specific embodiment, the first end of the single carbon nanotube is suspended.

[0010] In a specific embodiment, the thermal insulation member is a thermal insulation layer, the thermal insulation layer is arranged on the surface of the recording electrode, and the carbon nanotube structure is arranged on the surface of the thermal insulation layer away from the recording electrode; the first end of the single carbon nanotube extends out of the first end of the recording electrode.

[0011] In a specific embodiment, the thermal insulation member is a thermal insulation bracket; one end of the thermal insulation bracket is connected to the magnetic recording element, and at least a portion of the thermal insulation bracket is suspended in the air, the carbon nanotube structure is arranged on the thermal insulation bracket, and the first end of the single carbon nanotube extends out of the end of the thermal insulation bracket.

[0012] In a specific embodiment, the magnetic recording element further includes a yoke connected to the recording pole, a return pole connected to the yoke, and a coil wound around the return pole; the thermal insulation bracket is connected to the yoke; The thermal insulation bracket includes a connecting portion and a bending portion; the connecting portion is connected to the magnetic yoke, and the bending portion is bent relative to the connecting portion toward a side close to the recording pole; The heat generating element is a light-to-heat conversion layer; the light-to-heat conversion layer is arranged on the side of the bent portion facing the magnetic yoke; a light reflecting layer is arranged between the light-to-heat conversion layer and the bent portion; The first end of the single carbon nanotube is suspended on a side of the bent portion away from the magnetic yoke.

[0013] In a specific embodiment, the carbon nanotube structure is the single carbon nanotube; the second end of the single carbon nanotube is connected to the heating element; or The carbon nanotube structure includes a carbon nanotube bundle and the single carbon nanotube; the second end of the single carbon nanotube is connected to the carbon nanotube bundle, and the first end of the single carbon nanotube extends out of the carbon nanotube bundle; the carbon nanotube bundle is connected to the heating element; or The carbon nanotube structure includes a carbon nanotube film and the single carbon nanotube; the second end of the single carbon nanotube is connected to the carbon nanotube film, and the first end of the single carbon nanotube extends out of the carbon nanotube film; the carbon nanotube film is connected to the heating element.

[0014] To solve the above technical problems, another technical solution adopted by the present application is to provide a magnetic recording method for changing the magnetic moment direction of a magnetic domain in a magnetic storage medium; comprising: placing the first end of the thermally assisted magnetic recording head and the first end of the single carbon nanotube close to the magnetic storage medium; the thermally assisted magnetic recording head is any one of the thermally assisted magnetic recording heads mentioned above; By stimulating the heating element, the heating element generates heat, and heats the single magnetic domain in the magnetic storage medium through the first end of the single carbon nanotube; A recording magnetic field is applied to the individual magnetic domains by a magnetic recording element in the heat-assisted magnetic recording head to write data.

[0015] In a specific embodiment, the step of placing the first end of the heat-assisted magnetic recording head and the first end of the single carbon nanotube close to the magnetic storage medium includes: The first end of the single carbon nanotube is in contact with the magnetic storage medium, and the first end of the recording pole is spaced apart from the magnetic storage medium.

[0016] Beneficial effects of the embodiments of the present application: The present application provides a thermally assisted magnetic recording head for changing the magnetic moment direction of a magnetic domain in a magnetic storage medium. The thermally assisted magnetic recording head includes a magnetic recording element, a thermal insulation member, and a heating assembly; wherein the magnetic recording element is used to generate a recording magnetic field; the magnetic recording element includes a recording pole for applying a recording magnetic field; the thermal insulation member is disposed on the magnetic recording element; and the heating assembly is disposed on the thermal insulation member. wherein the heating assembly includes a heating element and a carbon nanotube structure; the heating element is used to generate heat; the carbon nanotube structure; one end of the carbon nanotube structure is connected to the heating element for conducting the heat generated by the heating element; wherein the carbon nanotube structure includes a single carbon nanotube, the first end of the single carbon nanotube away from the heating element is a free end, and is used to heat a single magnetic domain in the magnetic storage medium. By placing a carbon nanotube structure and a heating element on the magnetic recording element and utilizing the high axial thermal conductivity of the carbon nanotubes, the heat generated by the heating element can be efficiently transferred through the carbon nanotube structure to the free end of a single carbon nanotube, thereby heating a single magnetic domain to be heated. As can be understood, since the diameter of a single carbon nanotube can be as small as a few nanometers, the free end of a single carbon nanotube can precisely heat a smaller single magnetic domain, effectively increasing the storage density of the magnetic storage medium. Furthermore, the heating assembly has a simple structure, low manufacturing cost, and does not damage the magnetic material. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of a thermally assisted magnetic recording head provided in the first embodiment of the present application; Figure 2 for Figure 1 A schematic structural diagram of a heat insulating member and a heating assembly in a heat-assisted magnetic recording head is shown; Figure 3 A schematic structural diagram of a heat insulating member and a heating assembly in a heat-assisted magnetic recording head provided in a second embodiment of the present application; Figure 4 A schematic structural diagram of a heat insulating member and a heating assembly in a heat-assisted magnetic recording head provided in a third embodiment of the present application; Figure 5 A schematic structural diagram of a heat insulating member and a heating assembly in a heat-assisted magnetic recording head provided in a fourth embodiment of the present application; Figure 6 A schematic structural diagram of a thermally assisted magnetic recording head provided in a fifth embodiment of the present application; Figure 7 A schematic structural diagram of a heat-assisted magnetic recording head provided in a sixth embodiment of the present application; Figure 8 A schematic structural diagram of a heat-assisted magnetic recording head provided in a seventh embodiment of the present application; Figure 9 A schematic diagram of the steps of a magnetic recording method provided in an embodiment of the present application; Figure 10 for Figure 9 Schematic diagram of the structure of step S1; Figure 11 for Figure 9 Schematic diagram of the structure of step S3 in FIG.

[0018] 100-thermally assisted magnetic recording head; 200-magnetic storage medium; 1-magnetic recording element; 2-thermal insulation; 3-heating assembly; 4-sensor; 5-magnetic domain; 6-laser light source; 11-recording pole; 12-magnetic yoke; 13-return pole; 14-coil; 21-thermal insulation layer; 22-thermal insulation bracket; 31-heating element; 32-carbon nanotube structure; 111-first end of the recording pole; 121-through hole; 221-connecting portion; 222-bending portion; 223-extension portion; 311-photothermal conversion layer; 312-non-magnetic metal heating circuit; 313-light reflecting layer; 321-single carbon nanotube; 322-carbon nanotube bundle; 323-carbon nanotube film; 3211-first end of a single carbon nanotube; 3212-second end of a single carbon nanotube. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0020] The terms "first," "second," and "third" in this application are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features identified. Therefore, features identified as "first," "second," or "third" may explicitly or implicitly include at least one of such features. In the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined. All directional designations in the embodiments of this application (such as up, down, left, right, front, back, etc.) are intended only to illustrate the relative positional relationships and movement of components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional designations will also change accordingly. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to such process, method, product, or apparatus.

[0021] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0022] Existing heat-assisted magnetic recording methods use a heat-assisted magnetic recording head to record data on a magnetic storage medium with a high coercivity. Data is recorded by transiently heating the magnetic domains of the medium where the data is to be recorded, thereby raising their temperature. Because the coercivity of the magnetic domains decreases with increasing temperature, data can be recorded on the magnetic storage medium even with a very weak magnetic field. After data recording, the temperature of the magnetic domains in the magnetic storage medium where the data is recorded decreases, increasing their coercivity and achieving stable storage.

[0023] However, in heat-assisted magnetic recording, laser heating of magnetic domains is difficult due to the large laser spot size. Even with complex near-field optical techniques, it is difficult to control the spot diameter below 50 nanometers. Current magnetic domain sizes can reach 22 nanometers or even as low as 10 nanometers. Therefore, the large spot size makes it difficult to accurately heat smaller magnetic domains, making it impossible to heat only the single magnetic domain to be recorded data, while also not heating other magnetic domains near that domain, which is not conducive to improving the storage density of magnetic storage media. Electron beam heating of magnetic domains requires a vacuum and high-pressure environment, resulting in a complex structure and the electron beam is prone to damage to magnetic materials.

[0024] Based on this, the embodiments of the present application provide a thermally assisted magnetic recording head and a magnetic recording method, which can effectively improve the storage density of the magnetic storage medium; it has a simple structure, low manufacturing cost, and will not cause damage to the magnetic material.

[0025] The present application is described in detail below with reference to the accompanying drawings and embodiments.

[0026] See Figure 1 , Figure 1 A schematic structural diagram of a thermally assisted magnetic recording head provided in the first embodiment of the present application; Figure 2 for Figure 1 The following is a schematic diagram of the structure of the thermal insulation and heating assembly in a thermally assisted magnetic recording head. A first embodiment of the present application provides a thermally assisted magnetic recording head 100 for changing the magnetic moment direction of magnetic domains in a magnetic storage medium to record or erase data on the magnetic storage medium. The thermally assisted magnetic recording head 100 may include a magnetic recording element 1, a thermal insulation 2, and a heating assembly 3.

[0027] The magnetic recording element 1 is used to generate a recording magnetic field when the thermally assisted magnetic recording head 100 is in operation, thereby flipping the magnetic moment direction of the magnetic domains and writing data to the magnetic storage medium. The magnetic recording element 1 includes a recording pole 11 for applying the recording magnetic field and focusing the magnetic field on the surface of the magnetic storage medium. The recording pole 11 can be made of a material that is resistant to high temperatures and has a high saturation magnetization.

[0028] Combine Figure 1 and Figure 2 Thermal insulator 2 is disposed on magnetic recording element 1, and heating assembly 3 is disposed on thermal insulator 2. Heating assembly 3 instantaneously heats the magnetic domains where data is to be recorded, increasing their temperature and reducing their coercive force, thereby facilitating the reversal of the magnetic moment direction of the magnetic domains at recording pole 11 and completing data recording. Thermal insulator 2 prevents heat generated by heating assembly 3 from being transferred to magnetic recording element 1, preventing excessive temperature from affecting recorded data. Thermal insulator 2 can be made of non-magnetic material to avoid adversely affecting the recording magnetic field generated by recording pole 11.

[0029] Specifically, the heating component 3 may include a heating element 31 and a carbon nanotube structure 32. The heating element 31 is used to generate heat; the carbon nanotube structure 32 includes at least one single carbon nanotube 321, and the first end 3211 of the single carbon nanotube 321 away from the heating element 31 is a free end, which is used to heat a single magnetic domain in the magnetic storage medium. The axial thermal conductivity of the carbon nanotube is much greater than the radial thermal conductivity, so the heat generated by the carbon nanotube structure 32 can be efficiently transferred to the first end 3211 of the single carbon nanotube; at the same time, the diameter of the single carbon nanotube 321 can be made small enough, so that when the size of the magnetic domain is small enough, the carbon nanotube structure 32 can only heat the single magnetic domain to be recorded data, and will not heat other magnetic domains near the magnetic domain, so as to facilitate recording data in a single magnetic domain.

[0030] Thus, by providing the carbon nanotube structure 32 and the heating element 31 on the magnetic recording element 1 and utilizing the high axial thermal conductivity of the carbon nanotubes, the heat generated by the heating element 31 can be efficiently transferred through the carbon nanotube structure 32 to the free end of a single carbon nanotube 321, thereby heating a single magnetic domain to be heated. It can be understood that since the diameter of a single carbon nanotube 321 can be as small as a few nanometers, the free end of a single carbon nanotube 321 can precisely heat a smaller single magnetic domain, effectively increasing the storage density of the magnetic storage medium. Furthermore, the heating assembly 3 has a simple structure, low manufacturing cost, and does not damage the magnetic material.

[0031] like Figure 2As shown, in a specific embodiment, the heating element 31 can be a light-to-heat conversion layer 311. The light-to-heat conversion layer 311 is configured to generate heat when exposed to light and conduct the generated heat to the first end 3211 of the single carbon nanotube through the carbon nanotube structure 32, thereby heating the magnetic domain. Specifically, the light-to-heat conversion layer 311 is a photothermal material that, through its specific structure, absorbs light of a specific wavelength and converts it into thermal energy through non-radiative relaxation, significantly increasing its temperature. Specifically, the photothermal material can be graphite.

[0032] Alternatively, the light-to-heat conversion layer 311 can be an optical blackbody material. By scattering light through a multilayer structure, nanopores / roughened surfaces, or an absorbing coating, it extends the optical path, suppresses light reflection and transmission, and achieves full-spectrum absorption. The absorbed light energy can be dissipated as heat, which is then conducted through the carbon nanotube structure 32 to the first end 3211 of the individual carbon nanotubes to heat the magnetic domains. Specifically, the optical blackbody material can be a super-aligned carbon nanotube array.

[0033] like Figure 2 As shown, in a specific embodiment, the carbon nanotube structure 32 can be a single carbon nanotube 321, so that the carbon nanotube structure 32 has a smaller specific heat capacity and higher thermal conductivity, thereby improving the heating rate and reducing heat loss. Specifically, the second end 3212 of the single carbon nanotube is connected to the heating element 31 to conduct the heat generated by the heating element 31 to the first end of the single carbon nanotube 321.

[0034] like Figure 1 As shown, in a specific embodiment, the thermal insulation member 2 can be a thermal insulation layer 21, which is arranged on the surface of the recording pole 11, and the heating element 31 and the carbon nanotube structure 32 are arranged on the surface of the thermal insulation layer 21 away from the recording pole 11, so as to avoid the heat of the heating element 31 and the carbon nanotube structure 32 being transferred to the magnetic recording element 1, resulting in the temperature of the magnetic recording element 1 being too high and affecting its recorded data.

[0035] The first end 111 of the recording pole is a free end, and is located at the same end as the first end 3211 of the single carbon nanotube. Specifically, the first end 3211 of the single carbon nanotube and the first end 111 of the recording pole can be arranged flush, facilitating the placement of the carbon nanotube structure 32 on the surface of the thermal insulation layer 21. Specifically, the carbon nanotube structure 32 can be metallic carbon nanotubes; it is understood that metallic carbon nanotubes have a stronger thermal conductivity, which can enhance the instantaneous heating effect of the heating component 3, making it easier to heat the magnetic domain to the target temperature.

[0036] like Figure 1As shown, in a specific embodiment, the thermally assisted magnetic recording head 100 may further include a sensor 4 for detecting the magnetic moment direction of magnetic domains in the magnetic storage medium to read data. Specifically, the sensor 4 is spaced apart from the magnetic recording element 1, with the spacing being less than 50 nanometers. When the thermally assisted magnetic recording head 100 moves relative to the magnetic storage medium, the sensor 4 converts the magnetic moment direction of the magnetic domains into a binary electrical signal, thereby completing the data reading.

[0037] The magnetic recording element 1 also includes a yoke 12 connected to the recording pole 11, a return pole 13 connected to the yoke 12, and a coil 14 wound around the return pole 13. Specifically, one end of the yoke 12 is connected to the recording pole 11, and the other end is connected to the return pole 13, to guide the magnetic field from the recording pole 11 through the dielectric layer to the return pole 13, forming a low-magnetic resistance closed loop and reducing magnetic field leakage. The return pole 13 is spaced relative to the recording pole 11, and the cross-sectional area of the return pole 13 is larger than that of the recording pole 11 to reduce the magnetic flux density and avoid magnetic saturation. A copper or copper-silver alloy wire is wound around the outer periphery of the return pole 13 to form the coil 14. When a pulse current is passed through it, the magnetic field is excited according to Ampere's circuit law. Due to the magnetic circuit guidance effect of the yoke 12, the magnetic field energy is concentrated on the first end 111 of the recording pole, causing the magnetic domain to be recorded in the magnetic storage medium to complete magnetization reversal with the assistance of heating.

[0038] See Figure 3 , Figure 3 This is a schematic diagram of the structure of the thermal insulation and heating assembly in the thermally assisted magnetic recording head provided in the second embodiment of the present application. The structure of the thermally assisted magnetic recording head 100 provided in the second embodiment of the present application is basically the same as the structure of the thermally assisted magnetic recording head 100 provided in the first embodiment of the present application, except that in the second embodiment, the heating element 31 can also be a non-magnetic metal heating circuit 312. The non-magnetic metal heating circuit 312 is configured to generate heat when energized and conduct the generated heat to the first end 3211 of the single carbon nanotube through the carbon nanotube structure 32 to heat the magnetic domain. The material of the non-magnetic metal heating circuit 312 is non-magnetic metal to avoid adversely affecting the recording magnetic field generated by the recording pole 11.

[0039] Specifically, both ends of the non-magnetic metal heating circuit 312 may be electrically connected to an external power source to form a closed loop so that the non-magnetic metal heating circuit 312 is energized and generates heat.

[0040] See Figure 4 , Figure 4This is a schematic structural diagram of the thermal insulation and heating assembly in the thermally assisted magnetic recording head provided in the third embodiment of the present application; the structure of the thermally assisted magnetic recording head 100 provided in the third embodiment of the present application is basically the same as the structure of the thermally assisted magnetic recording head 100 provided in the first embodiment of the present application, except that, in the third embodiment, the carbon nanotube structure 32 may include a carbon nanotube bundle 322 and a single carbon nanotube 321.

[0041] The carbon nanotube bundle 322 is connected to the heating element 31 to increase the contact area between the heating element 31 and the carbon nanotube structure 32, thereby enhancing the thermal conductivity. In addition, if individual carbon nanotubes in the carbon nanotube bundle 322 break due to defects or thermal stress, the remaining carbon nanotubes can still maintain their thermal conductivity, thereby improving the reliability of the heating component 3. The carbon nanotube bundle 322 can be prepared by melting carbon nanotube wires or filaments. The carbon nanotube wires or filaments can be formed by shrinking a carbon nanotube film by solvent evaporation. The carbon nanotube film can be formed by drawing a film from a super-aligned carbon nanotube array.

[0042] The second end 3212 of a single carbon nanotube is connected to the carbon nanotube bundle 322, and the first end 3211 of the single carbon nanotube extends from the carbon nanotube bundle 322 to conduct heat to the first end 3211 of the single carbon nanotube. The length a of the single carbon nanotube 321 is greater than or equal to 10 nanometers and less than or equal to 10 microns. This prevents the heat conduction section from being too short, resulting in insufficient thermal conductivity and an inability to effectively conduct heat generated by the heating section to the first end 3211 of the single carbon nanotube. It also prevents the heat conduction section from being too long, increasing the heat conduction time and affecting the heating rate. Specifically, the length a of the single carbon nanotube 321 can be any value of 10 nanometers, 100 nanometers, 500 nanometers, 1 micron, or 10 microns.

[0043] Of course, in some other embodiments, the carbon nanotube bundles 322 may also directly generate heat under laser irradiation to replace the heating element 31 as a heating component, so as to further simplify the structure and reduce the manufacturing cost.

[0044] See Figure 5 , Figure 5 This is a schematic diagram of the structure of the thermal insulation and heating assembly in the thermally assisted magnetic recording head provided in the fourth embodiment of the present application. The structure of the thermally assisted magnetic recording head 100 provided in the fourth embodiment of the present application is basically the same as the structure of the thermally assisted magnetic recording head 100 provided in the first embodiment of the present application, except that, in the fourth embodiment, the carbon nanotube structure 32 can also include a carbon nanotube film 323 and a single carbon nanotube 321. The carbon nanotube film 323 can be formed by drawing a film from a super-aligned carbon nanotube array or by rolling an aligned carbon nanotube array.

[0045] The carbon nanotube film 323 is connected to the heating element 31 to increase the contact area between the heating element 31 and the carbon nanotube structure 32, thereby enhancing thermal conductivity. Furthermore, if individual carbon nanotubes in the carbon nanotube film 323 break due to defects or thermal stress, the remaining carbon nanotubes will still maintain their thermal conductivity, improving the reliability of the heating element 3. The second end 3212 of a single carbon nanotube is connected to the carbon nanotube film 323, and the first end 3211 of a single carbon nanotube extends out of the carbon nanotube film 323 to conduct heat to the first end 3211 of the single carbon nanotube.

[0046] Of course, in some other embodiments, the carbon nanotube film 323 may also directly generate heat under laser irradiation to replace the heating element 31 as a heating component, so as to further simplify the structure and reduce manufacturing costs.

[0047] See Figure 6 , Figure 6 This is a schematic structural diagram of a thermally assisted magnetic recording head provided in a fifth embodiment of the present application. The structure of the thermally assisted magnetic recording head 100 provided in the fifth embodiment of the present application is basically the same as the structure of the thermally assisted magnetic recording head 100 provided in the first embodiment of the present application, with the difference that, in the fifth embodiment, the first end portion 3211 of the single carbon nanotube extends out of the first end portion 111 of the recording pole, so that the portion of the single carbon nanotube 321 close to the first end portion 3211 of the single carbon nanotube is suspended, thereby reducing the contact area between the single carbon nanotube 321 and the thermal insulation layer 21, thereby reducing the heat loss of the single carbon nanotube 321 during heat conduction, thereby enhancing the heating effect of the single carbon nanotube 321 on the magnetic domain.

[0048] The length b of the suspended portion of the first end 3211 of a single carbon nanotube is greater than or equal to 10 nanometers and less than or equal to 10 microns. This prevents the length b of the suspended portion from being too short, thereby failing to effectively reduce heat loss during heat conduction of the single carbon nanotube 321. Furthermore, the length b of the suspended portion is prevented from being too long, thereby causing the distance between the first end 111 of the recording pole and the magnetic storage medium to be too large during magnetic recording, thereby failing to effectively reverse the magnetic moment direction of the magnetic domain. Specifically, the length b of the suspended portion of the first end 3211 of a single carbon nanotube can be any value selected from 10 nanometers, 100 nanometers, 500 nanometers, 1 micron, or 10 microns.

[0049] In addition, the first end portion 3211 of the single carbon nanotube extends out of the first end portion 111 of the recording pole, so that when the thermally assisted magnetic recording head 100 is working, the distance between the single carbon nanotube 321 extending out of the recording pole 11 and the magnetic storage medium is closer, and the heat of the first end portion 3211 of the single carbon nanotube can be more effectively conducted to the surface of the magnetic storage medium, thereby further enhancing the heating effect of the single carbon nanotube 321 on the magnetic domain.

[0050] See Figure 7 , Figure 7 This is a schematic structural diagram of the thermally assisted magnetic recording head provided in the sixth embodiment of the present application; the structure of the thermally assisted magnetic recording head 100 provided in the sixth embodiment of the present application is basically the same as the structure of the thermally assisted magnetic recording head 100 provided in the fifth embodiment of the present application, the difference being that, in the sixth embodiment, the thermal insulation member 2 is a thermal insulation bracket 22.

[0051] Specifically, one end of the thermal insulation bracket 22 is connected to the magnetic recording element 1, and part of the thermal insulation bracket 22 is suspended to reduce the contact area between the thermal insulation bracket 22 and the recording pole 11, thereby reducing the heat loss of the heating element 31 and the carbon nanotube structure 32, and further enhancing the heating effect of the single carbon nanotube 321 on the magnetic domain.

[0052] Among them, the second end of the thermal insulation bracket 22 can be connected to the magnetic yoke 12, and the first end of the thermal insulation bracket 22 is bent relative to the second end toward the side away from the recording pole 11, so that the thermal insulation bracket 22 forms a bent structure; the carbon nanotube structure 32 is fixed on the first end of the thermal insulation bracket 22, so that the carbon nanotube structure 32 and the first end of the thermal insulation bracket 22 are suspended relative to the recording pole 11.

[0053] The first end 3211 of the single carbon nanotube extends beyond the first end of the thermal insulation bracket 22 to reduce heat loss of the carbon nanotube structure 32. Furthermore, the first end 3211 of the single carbon nanotube can also extend beyond the first end 111 of the recording electrode to further reduce heat loss of the carbon nanotube structure 32.

[0054] participate Figure 8 , Figure 8 This is a schematic structural diagram of a thermally assisted magnetic recording head provided in the seventh embodiment of the present application; the structure of the thermally assisted magnetic recording head 100 provided in the seventh embodiment of the present application is basically the same as the structure of the thermally assisted magnetic recording head 100 provided in the sixth embodiment of the present application, with the difference that, in the seventh embodiment, the thermal insulation bracket 22 is connected to the magnetic yoke 12 to increase the distance between the thermal insulation bracket 22 and the recording pole 11, further reducing the heat loss of the heating element 31 and the carbon nanotube structure 32.

[0055] Specifically, the thermal insulation bracket 22 may include a connecting portion 221, a bent portion 222, and an extending portion 223. The connecting portion 221 is connected to the yoke 12; the bent portion 222 is bent relative to the connecting portion 221 toward the side closer to the recording pole 11, with one end of the bent portion 222 connected to the connecting portion 221 and the other end extending toward the side closer to the recording pole 11 and spaced apart from the recording pole 11. The extending portion 223 has one end connected to the end of the bent portion 222 closer to the recording pole 11 and the other end extending away from the yoke 12, thereby forming a three-section structure that is perpendicular to and connected to each other.

[0056] The heating element 31 is disposed on the side of the bent portion 222 facing the magnetic yoke 12, and the heating element 31 is a light-to-heat conversion layer 311. The thermally assisted magnetic recording head 100 further includes a laser light source 6 for emitting laser light; a through hole 121 is provided in the portion of the magnetic yoke 12 corresponding to the light-to-heat conversion layer 311, through which the laser light can be irradiated onto the light-to-heat conversion layer 311 to generate heat. Of course, in other embodiments, the thermally assisted magnetic recording head 100 may also include a reflector structure in place of the through hole 121 to allow the laser light to irradiate the light-to-heat conversion layer 311.

[0057] Furthermore, a light reflecting layer 313 is provided between the light-to-heat conversion layer 311 and the bent portion 222 to reflect light passing through the light-to-heat conversion layer 311 onto the light-to-heat conversion layer 311 to avoid energy loss and further enhance the heating efficiency of the light-to-heat conversion layer 311 .

[0058] The first end 3211 of the single carbon nanotube is suspended on the side of the bend 222 away from the magnetic yoke 12 and is disposed on the side of the extension 223 closer to the recording pole 11. This minimizes the distance between the carbon nanotube structure 32 and the recording pole 11, thereby reducing the time interval between heating and magnetic recording of the same magnetic domain to be recorded. Specifically, the second end 3212 of the single carbon nanotube is connected to the heating element 31. The first end 3211 of the single carbon nanotube is bent relative to the second end 3212 of the single carbon nanotube in a direction away from the magnetic yoke 12 and extends beyond the end of the thermal insulation bracket 22 to further reduce heat loss from the carbon nanotube structure 32.

[0059] Among them, the distance c between the first end 111 of the recording pole and the first end 3211 of the single carbon nanotube can be equal to the distance between adjacent magnetic domains of the magnetic storage medium, so that after the first end 3211 of the single carbon nanotube heats the magnetic domain to be recorded, when the first end 111 of the recording pole is aligned with the magnetic domain to be recorded to write data, the first end 3211 of the single carbon nanotube can be aligned with the next adjacent magnetic domain to heat the next magnetic domain to be recorded.

[0060] An embodiment of the present application provides a thermally assisted magnetic recording head 100 for changing the magnetic moment direction of a magnetic domain in a magnetic storage medium. The thermally assisted magnetic recording head 100 includes a magnetic recording element 1, a thermal insulation member 2, and a heating assembly 3; wherein the magnetic recording element 1 is used to generate a recording magnetic field; the magnetic recording element 1 includes a recording pole 11 for applying a recording magnetic field; the thermal insulation member 2 is disposed on the magnetic recording element 1; and the heating assembly 3 is disposed on the thermal insulation member 2. wherein the heating assembly 3 includes a heating element 31 and a carbon nanotube structure 32; the heating element 31 is used to generate heat; the carbon nanotube structure 32; one end of the carbon nanotube structure 32 is connected to the heating element 31 for conducting the heat generated by the heating element 31; wherein the carbon nanotube structure 32 includes a single carbon nanotube 321, and the first end 3211 of the single carbon nanotube 321 away from the heating element 31 is a free end for heating a single magnetic domain in the magnetic storage medium. By arranging a carbon nanotube structure 32 and a heating element 31 on the magnetic recording element 1 and utilizing the high axial thermal conductivity of the carbon nanotubes, the heat generated by the heating element 31 can be efficiently transferred through the carbon nanotube structure 32 to the free end of a single carbon nanotube 321, thereby heating a single magnetic domain to be heated. It can be understood that since the diameter of a single carbon nanotube 321 can be as small as a few nanometers, the free end of a single carbon nanotube 321 can precisely heat a smaller single magnetic domain, effectively increasing the storage density of the magnetic storage medium. Furthermore, the heating assembly 3 has a simple structure, low manufacturing cost, and does not damage the magnetic material.

[0061] See Figures 9-11 , Figure 9 A schematic diagram of the steps of a magnetic recording method provided in an embodiment of the present application; Figure 10 for Figure 9 Schematic diagram of the structure of step S1; Figure 11 for Figure 9 The present application also provides a magnetic recording method for changing the magnetic moment direction of the magnetic domain 5 in the magnetic storage medium 200 to record or erase data on the magnetic storage medium 200. The steps of the magnetic recording method specifically include: Step S1: placing a first end portion of a heat-assisted magnetic recording head and a first end portion of a single carbon nanotube close to a magnetic storage medium.

[0062] Specifically, the thermally assisted magnetic recording head 100 is the thermally assisted magnetic recording head 100 according to any of the above embodiments.

[0063] The magnetic storage medium 200 is placed below the thermally assisted magnetic recording head 100. The servo control system precisely adjusts the relative positions of the thermally assisted magnetic recording head 100 and the magnetic storage medium 200 to ensure that the first end of the thermally assisted magnetic recording head 100 and the first end 3211 of the single carbon nanotube are aligned with the target track of the magnetic storage medium 200. This allows the magnetic recording element 1 in the thermally assisted magnetic recording head 100 to generate a magnetic field that flips the magnetic moment direction of the magnetic domain 5 in the magnetic storage medium 200, thereby enabling data writing. Furthermore, the heating assembly 3 heats the magnetic domain 5, thereby reducing the coercive force of the magnetic domain 5, facilitating data writing to the magnetic recording element 1.

[0064] See Figure 10 In some embodiments, the first end portion 3211 of the single carbon nanotube extends out of the first end portion 111 of the recording electrode. In the specific implementation of these embodiments, step S1 may further include: Step S11: making the first end of a single carbon nanotube contact with the magnetic storage medium, and the first end of the recording pole is spaced apart from the magnetic storage medium.

[0065] As will be appreciated, air is a poor conductor of heat. However, by placing the first end 3211 of a single carbon nanotube in direct contact with the magnetic storage medium 200, the heat from the first end 3211 of the single carbon nanotube is prevented from being conducted through the air to the recording magnetic domain 5. This effectively improves heat conduction efficiency, enhances heating efficiency, and reduces energy consumption. Furthermore, carbon nanotubes are flexible materials and will not damage the magnetic storage medium 200.

[0066] Step S2: stimulating the heating element to generate heat, and heating a single magnetic domain in the magnetic storage medium through the first end of the single carbon nanotube.

[0067] Specifically, when the disk drive is writing data, the thermally assisted magnetic recording head 100 is electrically connected to an external power supply, so that the thermally assisted magnetic recording head 100 can excite the heating element 31 by one of the methods such as laser irradiation or power supply, so that the heating element 31 converts light energy or electrical energy into thermal energy, and conducts the heat generated by the heating element 31 to the first end 3211 of the single carbon nanotube through the carbon nanotube structure 32 to heat the magnetic domain 5 to be recorded.

[0068] Specifically, by controlling the excitation time, the temperature of the magnetic domain 5 to be recorded is raised to a temperature close to or higher than its Curie temperature, thereby significantly reducing the coercive force of the magnetic domain 5 to be recorded, so that the magnetic recording element 1 can write data on the magnetic domain 5 to be recorded.

[0069] Step S3: applying a recording magnetic field to a single magnetic domain via a magnetic recording element in a heat-assisted magnetic recording head to write data.

[0070] Specifically, while heating the magnetic domain 5 or within a preset delay time after heating, the coil 14 wound on the return pole 13 can be energized to generate a high-intensity directional magnetic field, and the magnetic field energy can be concentrated on the first end 111 of the recording pole through the guidance of the magnetic yoke 12 to flip the magnetic moment direction of the magnetic domain 5 to be recorded and complete data writing.

[0071] See Figure 11 In some embodiments, the distance c between the first end 111 of the recording pole and the first end 3211 of the single carbon nanotube can be equal to the distance d between adjacent magnetic domains 5 of the magnetic storage medium 200. After the first end 3211 of the single carbon nanotube heats the magnetic domain 5 to be recorded, the magnetic storage medium 200 continues to move, aligning the first end 111 of the recording pole with the magnetic domain to be recorded and generating a recording magnetic field to flip the magnetic moment direction of the magnetic domain 5 to be recorded, thereby completing data writing. At the same time, because the distance c between the first end 111 of the recording pole and the first end 3211 of the single carbon nanotube is equal to the distance d between adjacent magnetic domains 5 of the magnetic storage medium 200, when the first end 111 of the recording pole is aligned with the magnetic domain 5 to be recorded, the first end 3211 of the single carbon nanotube can align with the next adjacent magnetic domain to heat the next magnetic domain to be recorded.

[0072] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A thermally assisted magnetic recording head for changing the magnetic moment direction of a magnetic domain in a magnetic storage medium; characterized in that: include: A magnetic recording element for generating a recording magnetic field; the magnetic recording element includes a recording pole for applying the recording magnetic field; a heat insulating member disposed on the magnetic recording element; A heating assembly is provided on the thermal insulation member; the heating assembly comprises: A heating element, used to generate heat; A carbon nanotube structure; one end of the carbon nanotube structure is connected to the heating element for conducting heat generated by the heating element; The carbon nanotube structure includes a single carbon nanotube, and the first end of the single carbon nanotube away from the heating element is a free end, which is used to heat the single magnetic domain in the magnetic storage medium.

2. The thermally assisted magnetic recording head according to claim 1, wherein: The heat generating element is a light-to-heat conversion layer; the light-to-heat conversion layer is configured to generate heat under light; or, The heating element is a non-magnetic metal heating circuit; the non-magnetic metal heating circuit is configured to generate heat when powered on.

3. The thermally assisted magnetic recording head according to claim 1, wherein: The heat insulating member is a heat insulating layer, the heat insulating layer is arranged on the surface of the recording electrode, and the carbon nanotube structure is arranged on the surface of the heat insulating layer away from the recording electrode; The first end of the recording electrode away from the heating element is a free end; the first end of the single carbon nanotube is flush with the first end of the recording electrode.

4. The thermally assisted magnetic recording head according to claim 1, wherein: The first end of the single carbon nanotube is suspended.

5. The thermally assisted magnetic recording head according to claim 4, wherein: The thermal insulation member is a thermal insulation layer, which is arranged on the surface of the recording electrode, and the carbon nanotube structure is arranged on the surface of the thermal insulation layer away from the recording electrode; the first end of the single carbon nanotube extends out of the first end of the recording electrode.

6. The thermally assisted magnetic recording head according to claim 4, wherein: The thermal insulation component is a thermal insulation bracket; one end of the thermal insulation bracket is connected to the magnetic recording element, and at least part of the thermal insulation bracket is suspended in the air, the carbon nanotube structure is arranged on the thermal insulation bracket, and the first end of the single carbon nanotube extends out of the end of the thermal insulation bracket.

7. The thermally assisted magnetic recording head according to claim 6, wherein: The magnetic recording element further includes a yoke connected to the recording pole, a return pole connected to the yoke, and a coil wound around the return pole; the thermal insulation bracket is connected to the yoke; The thermal insulation bracket includes a connecting portion and a bending portion; the connecting portion is connected to the magnetic yoke, and the bending portion is bent relative to the connecting portion toward a side close to the recording pole; The heat generating element is a light-to-heat conversion layer; the light-to-heat conversion layer is arranged on the side of the bent portion facing the magnetic yoke; a light reflecting layer is arranged between the light-to-heat conversion layer and the bent portion; The first end of the single carbon nanotube is suspended on a side of the bent portion away from the magnetic yoke.

8. The thermally assisted magnetic recording head according to claim 1, wherein: The carbon nanotube structure is the single carbon nanotube; the second end of the single carbon nanotube is connected to the heating element; or The carbon nanotube structure includes a carbon nanotube bundle and the single carbon nanotube; the second end of the single carbon nanotube is connected to the carbon nanotube bundle, and the first end of the single carbon nanotube extends out of the carbon nanotube bundle; the carbon nanotube bundle is connected to the heating element; or The carbon nanotube structure includes a carbon nanotube film and the single carbon nanotube; the second end of the single carbon nanotube is connected to the carbon nanotube film, and the first end of the single carbon nanotube extends out of the carbon nanotube film; the carbon nanotube film is connected to the heating element.

9. A magnetic recording method for changing the magnetic moment direction of a magnetic domain in a magnetic storage medium; characterized in that: include: placing the first end of the thermally assisted magnetic recording head and the first end of the single carbon nanotube close to the magnetic storage medium; the thermally assisted magnetic recording head is the thermally assisted magnetic recording head according to any one of claims 1 to 8; By stimulating the heating element, the heating element generates heat, and heats the single magnetic domain in the magnetic storage medium through the first end of the single carbon nanotube; A recording magnetic field is applied to the individual magnetic domains by a magnetic recording element in the heat-assisted magnetic recording head to write data.

10. The magnetic recording method according to claim 9, wherein The step of placing the first end of the heat-assisted magnetic recording head and the first end of the single carbon nanotube close to the magnetic storage medium comprises: The first end of the single carbon nanotube is brought into contact with the magnetic storage medium, and the first end of the recording pole of the heat-assisted magnetic recording head is spaced apart from the magnetic storage medium.

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