Magnetic particle membrane and method for producing the same

Abstract

The application discloses a kind of magnetic particle film and preparation method thereof.The preparation method of the magnetic particle film of the application comprises: quartz matrix is subjected to metal vapor vacuum arc ion implantation process, laser annealing process, to obtain magnetic particle film.The application obtains the preparation method of the magnetic particle film suitable for transparent substrate, simple process, effective magnetic modification, small and uniform particle size, high controllability and good repeatability by combining metal vapor vacuum arc ion implantation technology with nanosecond laser annealing, and setting and controlling by specific process parameters.Moreover, the magnetic particle film with sub-10 nanometer particle size and uniform distribution can be prepared by the above method, which has wide application prospect in high-density magnetic recording, micro-magnetic sensor and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of inorganic nanoparticle thin film and magnetic material, and particularly relates to a magnetic particle film and a preparation method thereof. BACKGROUND

[0002] Magnetic nanoparticle film has important application value in the fields of magnetic storage, permanent magnetic material, micro magnetic sensor and microwave absorption. Due to the characteristics of magnetic interaction, the application of magnetic material is mostly based on nanoscale as the basic material to form particle film, bulk or magnetic fluid. In magnetic storage, multiple or single particles are used for data bit recording, and nanometer particles are often used as the basis to form high-performance bulk materials in permanent magnetic materials. Based on the response of nanoparticles to magnetic field and the absorption of electromagnetic waves, high-sensitivity magnetic sensors and microwave absorption devices can be made.

[0003] The particle morphology, structure and performance in the particle thin film are affected by the preparation process. As a traditional magnetic material, cobalt nanoparticle film has many excellent properties, and its preparation technology has also been widely studied.

[0004] Traditional ion implantation technology has slow injection rate and low efficiency; while metal vapor vacuum arc (MEVVA) ion source has the characteristics of large beam current, which can realize rapid injection and shorten the preparation time. However, the high temperature in the preparation process has certain influence on the crystallinity of the material.

[0005] Traditional annealing method has long time and high energy consumption, and for easily oxidized materials, it also involves high vacuum equipment or needs to provide inert gas and reducing gas. Laser annealing has the characteristics of short time, high energy in pulse time, locality and low energy consumption. Although there is currently a technology of preparing magnetic particle film by MEVVA ion implantation method, and laser annealing is also used for magnetic ion implantation of semiconductor materials, but there are certain technical difficulties in applying laser annealing to the injection of magnetic ions into transparent (high laser transmittance) substrate by MEVVA injection technology. The reasons are as follows:

[0006] The mechanism and effect of using transparent quartz as substrate are different from those of using antiferromagnetic substrate. First, the particles formed by quartz and implanted material have no obvious magnetic interaction. Second, during laser annealing, the laser energy is mainly absorbed by the implanted material, and the interaction between laser and substrate is weak, so it is difficult to obtain an effective magnetic modification method with small particle size, high controllability and good repeatability.

[0007] Therefore, it is urgent to develop a simple and effective magnetic modification method for preparing magnetic particle film with small and uniform particle size, high controllability and good repeatability. SUMMARY

[0008] In order to overcome the problems existing in the prior art, the purpose of the present application is to provide a magnetic particle film and a preparation method thereof.

[0009] The technical solution is different from the application of MEVVA ion implantation technology to surface modification and improvement of material properties. The present solution is mainly aimed at the preparation of sub-10-nanometer magnetic particle films. Sub-10-nanometer magnetic particles are the basis for many magnetic materials to achieve high-performance applications, and their magnetic properties are significantly different from those of larger particles. For the structure and magnetic characteristics of the particles, the present technical solution further uses laser annealing to adjust the performance of the magnetic particle film within a certain range.

[0010] In order to achieve the above-mentioned purpose, the technical solution adopted by the present application is:

[0011] In the first aspect, the present application provides a preparation method of a magnetic particle film, comprising the following steps:

[0012] The quartz substrate is subjected to a metal vapor vacuum arc ion implantation process and a laser annealing process to obtain a magnetic particle film.

[0013] Preferably, the preparation method of the magnetic particle film comprises the following steps: 17 17 -2

[0014] Preferably, the preparation method of the magnetic particle film comprises the following steps:

[0015] 1) After the quartz substrate is subjected to a differential treatment, a quartz substrate with several equal-area region units is obtained;

[0016] 2) One side of the quartz substrate with several region units is selected and subjected to a metal vapor vacuum arc ion implantation process and a laser annealing process to obtain a magnetic particle film;

[0017] Preferably, the preparation method of the magnetic particle film comprises the following steps: 17 17 -2

[0018] Preferably, the differential treatment in step 1) is specifically performed as follows: after the quartz substrate is cut into a cuboid by laser cutting, a scratch is drawn on the back of the quartz substrate by laser. The scratch is used to divide the equal-area unit regions, and the quartz substrate is divided into several equal-area region units without breaking, which facilitates the separation of the single sample after the preparation is completed, so as to obtain a small-size magnetic particle film that can be used for a micro-magnetic sensor.

[0019] ​​​​​​It should also be noted that the depth of the scratch is 1 / 5 of the substrate thickness; the front side of the quartz substrate (without scratches) is the metal vapor vacuum arc ion implantation surface, which is also the side where the laser spot needs to be aligned during laser annealing.

[0020] Preferably, step 1) further includes a step of cleaning the quartz substrate. Specifically, the cleaning agent used to clean the quartz substrate is selected from one or more of acetone, ethanol, and deionized water.

[0021] Preferably, the implantation dose of the metal vapor vacuum arc ion implantation in step 2) is 2.5 × 10⁻⁶. 17 ~3.5×10 17 cm -2 .

[0022] More preferably, the implantation dose of the metal vapor vacuum arc ion implantation in step 2) is 3.0 × 10⁻⁶. 17 cm -2 .

[0023] Preferably, the element used in step 2) of the metal vapor vacuum arc ion implantation is selected from at least one of cobalt, iron, and nickel.

[0024] More preferably, the element used in step 2) of the metal vapor vacuum arc ion implantation is selected from cobalt.

[0025] Preferably, the parameters for metal vapor vacuum arc ion implantation in step 2) are as follows:

[0026] Vacuum degree is 4×10 -4 ~6×10 -4 Pa, the ion generation frequency is 5-15 Hz, the injection energy is fixed at 20-60 keV, and the target material of the ion source is cobalt.

[0027] Further preferably, the parameters for metal vapor vacuum arc ion implantation in step 2) are as follows:

[0028] Vacuum degree is 5×10 -4 Pa, the ion generation frequency is 10Hz, the injection energy is fixed at 45keV, and the target material of the ion source is cobalt.

[0029] Preferably, the laser annealing process in step 2) specifically involves irradiating the ion-implanted surface of the quartz substrate of the discontinuous regional unit.

[0030] Preferably, the laser annealing process in step 2) further includes: discarding adjacent quartz substrates after irradiation. This ensures that the laser spot does not repeatedly irradiate the ion implantation surface of the same region, thereby improving the controllability and repeatability of laser annealing.

[0031] Specifically, the irradiation is performed on every other region on the quartz strip, for example, the first region unit is processed, then the third unit region is processed, and the intermediate region is discarded. Meanwhile, the sample is kept at a certain distance to avoid the influence of the subsequent operation on the previous sample.

[0032] Preferably, the instrument for the laser annealing process in step 2) is a Qsmart-850 laser.

[0033] Preferably, the wavelength of the laser for the laser annealing process in step 2) is 400-600 nm.

[0034] Specifically, the Qsmart-850 laser is a nanosecond laser produced by Quantel Company, and the wavelength of the laser used is 532 nm.

[0035] Preferably, the parameters of the laser annealing process in step 2) are set as follows:

[0036] 1 a pulse signal, the pulse signal is characterized by low energy, the instrument parameter delay (hereinafter referred to as delay) is 107 microseconds, and the single pulse energy is about 42 millijoules;

[0037] or,

[0038] 1 a pulse signal, the pulse signal is characterized by high energy, the delay is 57 microseconds, and the single pulse energy is about 142 millijoules.

[0039] Specifically, the irradiation energy is controlled by adjusting the delay time, and the smaller the delay time, the higher the energy.

[0040] Preferably, the ratio of the area of the region unit of the quartz substrate to the area of the selected beam spot of the laser annealing is 1: (2-3.5).

[0041] Further preferably, when the area of the region unit of the quartz substrate is 5 mm x 5 mm, the diameter of the selected beam spot of the laser annealing in step 2) can be adjusted from 1 mm to several centimeters (determined by the lens); more preferably, the diameter of the selected beam spot of the laser annealing in step 2) is adjusted to about 10 mm.

[0042] In the second aspect, the application provides a magnetic particle film prepared by the preparation method of the first aspect.

[0043] Preferably, the magnetic particle film comprises a quartz substrate layer and a cobalt magnetic particle injection layer, and the diameter of the cobalt particles in the cobalt magnetic particle injection layer is <10 nm.

[0044] Preferably, the diameter of the cobalt particles in the cobalt magnetic particle injection layer is 8-12 nm.

[0045] Preferably, the cobalt magnetic particle injection layer has a thickness of about 100 nm.

[0046] The present application has the advantages that: the present application combines metal vapor vacuum arc ion implantation technology with nanosecond laser annealing, and sets specific process parameters to control, to obtain a preparation method of a magnetic particle film with a small size, a uniform distribution, a high controllability, a good repeatability, a simple process, a suitable transparent substrate, and an effective magnetic modification. In addition, the magnetic particle film prepared by the method has a uniform particle size and a uniform distribution, and has a wide application prospect in high-density magnetic recording and micro-magnetic sensors.

[0047] In other words, the present application implants a proper dose of magnetic ions into a transparent quartz substrate with a specific size by MEVVA ion implantation technology, and then irradiates the implanted sample under a nanosecond laser, to effectively realize rapid annealing and effective magnetic modification, and to controllably obtain a sub-10-nanometer particle film.

[0048] Specifically, the present application has the following advantages:

[0049] (1) The present application uses ion implantation technology to adjust the implantation energy and dose, to realize the control of the implantation depth and the adjustment of the particle size and distribution; the small-size particles obtained by the method have stable magnetic particle properties, and are more critical for practical applications.

[0050] (2) The MEVVA ion implantation technology used in the present application can use conductive solids as ion sources, and common iron, cobalt, nickel and other materials can be used as raw materials. Compared with traditional implantation technology, the present application has a larger beam current, a faster implantation speed, and a shorter time consumption. A single dose of implantation can be completed within 1 hour, while traditional implantation technology takes several to ten hours. Due to the large implantation beam current, the interaction between the implanted ions and the substrate results in a high temperature during implantation, which is beneficial to the crystallization of the implanted material in the substrate.

[0051] (3) The preparation method of the present application uses nanosecond laser with a very short time consumption to anneal the material, which can save energy and time. For the sample of cobalt implanted in quartz, one pulse can change the structure and properties of the material. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 FIG. 1 is a process flow diagram of the preparation method of the small-size magnetic particle film of the present application;

[0053] Figure 2 FIG. 3 is a low-temperature (20K) magnetic hysteresis loop diagram of the magnetic particle film of Example 1;

[0054] Figure 3 FIG. 5 is a cobalt element imaging diagram of the magnetic particle film of Example 2;

[0055] Figure 4 Elemental profile of Si, Co, C, O in the magnetic particle film of Example 2 in the depth direction;

[0056] Figure 5 Cross-sectional TEM image of the magnetic particle film of Example 2;

[0057] Figure 6 Low-temperature (20K) hysteresis loop of the magnetic particle film of Example 2;

[0058] Figure 7 Cobalt element imaging of the magnetic particle film of Example 3;

[0059] Figure 8 Elemental profile of Si, Co, C, O in the magnetic particle film of Example 3 in the depth direction;

[0060] Figure 9 Cross-sectional TEM image of the magnetic particle film of Example 3;

[0061] Figure 10 Low-temperature (20K) hysteresis loop of the magnetic particle film of Example 3. DETAILED DESCRIPTION

[0062] The content of the present application will be further explained in detail through specific examples.

[0063] Unless otherwise specified, the unit of the injection amount in the present application is "cm -2 " which is "ions·cm -2 "; the quartz substrates used in the examples of the present application are all transparent quartz substrates; the metal vapor vacuum arc (MEVVA) ion implanter used in the present application is developed by Beijing Normal University, and the laser is Qsmart-850 laser produced by Quantel Company, with a wavelength of 532nm, which has a very high transmittance in quartz substrates.

[0064] The present application provides a preparation method of a magnetic particle film, which comprises the following steps: designing a transparent quartz as a substrate, and using a metal vapor vacuum arc (MEVVA) ion implantation technology to implant a proper dose of magnetic ions into the quartz with a specific size to obtain a sample after implantation of the magnetic ions; then, the sample after implantation of the magnetic ions is uniformly and rapidly annealed by irradiation under a nanosecond laser with a spot diameter of 1mm to several centimeters to obtain a magnetic particle film material with a size of sub-10 nanometers.

[0065] In particular, the present application uses high-energy ion implantation to implant magnetic ions in a quartz substrate, which is a medium-dose implantation method. When the dose is very low, the implanted atoms are dispersed in the substrate. When the dose is very high, the particles are in contact with each other and exhibit a continuous characteristic. Medium-dose implantation can obtain nanoparticles with a certain size distribution. The use of MEVVA (metal vapor vacuum arc) ion implantation technology greatly improves the preparation speed. Due to the collision between the large beam and the substrate, the temperature is relatively high during the implantation process, which has a heating effect on the substrate, thereby obtaining a certain amount of nanoparticles. For magnetic particle films, in order to obtain a magnetic particle film with good performance and a sub-10-nanometer level (particle size < 10 nm), it is necessary to control the implantation amount and depth of the element. However, the magnetic properties of the particle film without heat treatment are often poor. Annealing treatment improves the performance of the nanoparticles by affecting the distribution, particle size, and crystallinity of the nanoparticles.

[0066] If a larger area of the magnetic particle film needs to be prepared, it is not necessary to divide the area by laser (i.e., micro-processing), but only to adjust the area of ion implantation and the spot area of the laser, so that a large-area magnetic particle film can be obtained. This material is suitable for high-density magnetic storage.

[0067] If a small-area sample needs to be uniformly processed, it is only necessary to adjust the laser focusing area to be larger than the orthographic projection area of the sample. The preparation method further comprises the following steps: (1) making scratches with a specific interval on the back of the quartz substrate using a laser (the depth of the scratches is not more than 1 / 5 of the thickness of the substrate), and continuously dividing the area units with the same area (the area units are sequentially recorded as the first area, the second area, the third area,..., and the nth area, where n is an integer); and (2) during laser annealing, the areas with a specific interval are sequentially irradiated; for example, the first area, the third area,..., and the nth area are irradiated. In this way, the energy of a single pulse can be utilized (batch annealing is performed under a single pulse, and the laser energy density is low), and repeated irradiation of the same area is avoided, so that a (uniformly annealed) magnetic particle film material can be obtained. This small-size magnetic particle film material is suitable for use in a micro-magnetic sensor (see Figure 1 ).

[0068] Example 1

[0069] The present embodiment provides a preparation method of a magnetic particle film of a quartz substrate implanted with cobalt based on different implantation doses, which comprises the following steps:

[0070] 1) Pretreatment: divide a quartz substrate with a size of 50 mm x 5 mm x 0.5 mm (length x width x height, the height refers to the thickness) into several quartz substrates with a size of 5 mm x 5 mm (length x width, i.e., the orthographic projection area is 25 mm 2 ) x 0.5 mm, and sequentially clean the quartz substrates with acetone, ethanol, and deionized water;

[0071] 2) Metal Vapor Vacuum Arc (MEVVA) ion implantation process: the pre-processed quartz substrate is placed in the implantation chamber, and one side of the quartz substrate is opposite to the cobalt ion source, and the parameters are set as follows:

[0072] The ion generation frequency is 10 Hz, the implantation energy is fixed at 45 keV, the vacuum degree in the implantation chamber is 5 x 10 - 4 Pa, the implantation voltage is set to 45 kV, the ion beam generation frequency is 10 Hz, and the beam current is about 5-10 mA;

[0073] The implantation amount of the quartz substrate of different groups is set to 1.0 x 10 17 cm -2 , 2.0 x 10 17 cm -2 , 3.0 x 10 17 cm -2 , 4.0 x 10 17 cm -2 , 5.0 x 10 17 cm -2 , to obtain five groups of magnetic particle films with different cobalt ion implantation amounts.

[0074] The low-temperature (20 K) magnetic hysteresis loop of the magnetic particle film with different implantation doses in Example 1 is tested by MPMS system, and the test result is shown in Figure 2 .

[0075] As can be seen from Figure 2 : in Example 1, when the implantation amount of cobalt ions is 4.0 x 10 17 cm -2 , 5.0 x 10 17 cm -2 , the hysteresis characteristics (such as Bm, Br and Hc) of the two high-implantation-dose samples prepared are relatively close, indicating that the cobalt element in the material is close to one of saturation, saturation and supersaturation, the preparation raw material cost is relatively high, and it is difficult to obtain a magnetic particle film with uniform distribution and particle size meeting the requirement of sub-10 nanometers; when the implantation amount of cobalt ions is 1.0 x 10 17 cm -2 , 2.0 x 10 17 cm -2 , two low-implantation-dose samples are prepared, and the remanence is relatively low, indicating that the magnetic material cobalt in the film material is less or not uniformly distributed, and it is also difficult to prepare a magnetic particle film with uniform distribution and particle size meeting the requirement of sub-10 nanometers. Based on the above analysis, although the medium implantation dose (3.0 x 10 17 cm -2) of the sample are in the middle value, but based on the above analysis, the present application is based on the sample of the medium injection dose (3.0×10 17 cm -2 ) and aims to obtain a preparation method of the magnetic particle film which has strong controllability, good repeatability, can prepare the sub-10 nanometer magnetic particle film, has good magnetic performance improvement effect and is suitable for practical application.

[0076] Example 2

[0077] The present embodiment provides a method for preparing a sub-10 nanometer magnetic particle film based on high-energy ion implantation and nanosecond laser annealing, which specifically comprises the following steps:

[0078] 1) Differential processing: draw equidistant scratches on the back of a 50mm×5mm×0.5mm (length×width×height, height refers to thickness) quartz substrate by laser processing, and the scratch depth is not more than 1 / 5 of the thickness of the substrate. These scratches divide the quartz substrate into several 5mm×5mm (length×width, i.e., the projected area is 25mm 2 ) area units. The quartz substrate is sequentially cleaned with acetone, ethanol and deionized water;

[0079] 2) Metal vapor vacuum arc (MEVVA) ion implantation process: place the differential processed quartz substrate into the implantation chamber, and make the front surface (i.e., the surface without scratches) of the differential processed quartz substrate face the cobalt ion source. Set the vacuum degree in the implantation chamber to 5×10 -4 Pa, the implantation voltage to 45kV, the ion generation frequency to 10Hz, the implantation energy to 45keV, the ion beam generation frequency to 10Hz, the target beam current to 5-10mA, and the implantation amount to 3.0×10 17 cm -2 , to obtain a cobalt ion implanted quartz substrate;

[0080] 3) Annealing treatment: transfer the implanted sample to the sample stage of a nanosecond laser, and set the parameters of the nanosecond laser as follows: 1 pulse signal, low relative energy, delay time of 107 microseconds, and single pulse energy of about 42 millijoules;

[0081] ; and use the spot of the nanosecond laser to irradiate the implantation surface of the odd area unit. That is, after the nanosecond laser irradiates the first area unit, it is moved to the third area unit above to irradiate, and then it is moved to the fifth area unit above to irradiate, and so on, so as to complete the annealing process and obtain several sub-10 nanometer magnetic particle films;

[0082] In step 3), after the single area unit is annealed, the second, fourth, sixth area units, and so on are abandoned to avoid the laser irradiation on the irradiated area in the subsequent irradiation.

[0083] It should be noted that, in step 2), the ion implantation dose can be calculated according to the average charge of cobalt ions, the cumulative charge number, and the implantation area. Meanwhile, if the area of the ion beam is much larger than the area of the substrate, the entire implantation surface of the substrate can be implanted with specific ions.

[0084] The transmission electron microscope image of the cross section of the magnetic particle film of Example 2 is shown in FIG. 4; the cobalt element imaging diagram of the magnetic particle film of Example 2 in the depth direction is shown in FIG. 5; the element distribution diagrams of Si, Co, C, and O in the magnetic particle film of Example 2 in the depth direction are shown in FIGS. 6, 7, 8, and 9, respectively. Figure 5 Figure 3 Figure 4

[0085] Figure 3 Figure 4 It can be seen from FIGS. 4 to 9 that: according to the cobalt element imaging diagram and the element distribution diagram in the depth direction, it can be illustrated that the cobalt element successfully implanted by the metal vapor vacuum arc (MEVVA) ion technology is in the quartz substrate, and has a certain distribution in the depth direction. The distribution rule that the cobalt concentration first increases and then decreases in the depth range of 50 nm to 150 nm can be obviously seen, and the cobalt element is mainly distributed in the range of 100 nm.

[0086] It should be noted that the Si and O in the element distribution diagram in the depth direction come from the quartz substrate.

[0087] Figure 5 It can be seen from FIGS. 4 to 9 that: according to the cobalt element imaging diagram and the element distribution diagram in the depth direction, it can be illustrated that the cobalt element successfully implanted by the metal vapor vacuum arc (MEVVA) ion technology is in the quartz substrate, and has a certain distribution in the depth direction. The distribution rule that the cobalt concentration first increases and then decreases in the depth range of 50 nm to 150 nm can be obviously seen, and the cobalt element is mainly distributed in the range of 100 nm.

[0088] The low-temperature (20 K) magnetic hysteresis loop diagram of the magnetic particle film of Example 2 is shown in FIG. 10. Figure 6

[0089] Figure 6 It can be seen from FIGS. 4 to 9 that: according to the cobalt element imaging diagram and the element distribution diagram in the depth direction, it can be illustrated that the cobalt element successfully implanted by the metal vapor vacuum arc (MEVVA) ion technology is in the quartz substrate, and has a certain distribution in the depth direction. The distribution rule that the cobalt concentration first increases and then decreases in the depth range of 50 nm to 150 nm can be obviously seen, and the cobalt element is mainly distributed in the range of 100 nm.

[0090] Example 3

[0091] The embodiment provides a method for preparing a sub-10-nanometer magnetic particle film based on high-energy ion implantation and nanosecond laser annealing, and specifically comprises the following steps. ​​​​​​​​

[0092] 1) Differential processing: the back of a quartz substrate with a size of 50mm x 5mm x 0.5mm (length x width x height, height refers to thickness) is divided into equidistant scratches by laser processing, and the scratch depth is not more than 1 / 5 of the thickness of the substrate. These scratches divide the quartz substrate into several 5mm x 5mm (length x width, i.e. the area of the orthographic projection is 25mm 2 ) region units. The quartz substrate is sequentially cleaned with acetone, ethanol and deionized water;

[0093] 2) Metal vapor vacuum arc (MEVVA) ion implantation process: the differential processed quartz substrate is placed in the implantation chamber, and the front surface (i.e. the surface without scratches) of the differential processed quartz substrate is directed towards the cobalt ion source. The vacuum degree in the implantation chamber is set to 5 x 10 -4 Pa, the implantation voltage is set to 45kV, the ion generation frequency is 10Hz, the implantation energy is fixed at 45keV, the ion beam generation frequency is 10Hz, the target beam current is 5-10mA, and the implantation amount is set to 3.0 x 10 17 cm -2 , to obtain a cobalt ion implanted quartz substrate;

[0094] 3) Annealing process: the implanted sample is transferred to the nanosecond laser sample stage, and the nanosecond laser is set as follows: 1 pulse, delay time of 57 microseconds, and single pulse energy of about 142 millijoules. The implantation surface of the odd region units is irradiated with laser. After the nanosecond laser irradiates the first region unit, it is moved to the third region unit to irradiate, then to the fifth region unit to irradiate, and so on, to complete the annealing process and obtain several sub-10 nanometer magnetic particle films;

[0095] In step 3), after the annealing process of the odd region units, the second, fourth, sixth, and so on, adjacent region units are discarded to avoid laser irradiation on the already irradiated region during subsequent irradiation.

[0096] It should be noted that, in step 2), the ion implantation dose can be calculated according to the average charge of cobalt ions, the cumulative charge number, and the implantation area. If the area of the ion beam is much larger than the area of the substrate, the implantation surface of the entire substrate can be implanted with a specific ion source.

[0097] The transmission electron microscope image of the cross-section of the magnetic particle film of Example 3 is shown in Figure 9 , and the cobalt element imaging graph of the magnetic particle film of Example 3 in the depth direction is shown in Figure 7As shown; the elemental distribution of Si, Co, C, and O in the magnetic particle film of Example 3 along the depth direction is shown in the figure. Figure 8 As shown.

[0098] Depend on Figure 7 and Figure 8 It can be seen from the cobalt element imaging and the elemental distribution map in the depth direction that the cobalt element successfully implanted in the quartz matrix using metal vapor vacuum arc (MEVVA) ion technology has a certain distribution in the implantation depth direction. A clear distribution pattern of increasing and then decreasing cobalt concentration can be observed in the depth range of 50 nm to 160 nm, with the cobalt element mainly distributed in the 100 nm range. Compared with Example 2, the higher energy annealing did not significantly change the distribution of cobalt element.

[0099] It should also be noted that the Si and O in the elemental distribution map in the depth direction come from the quartz matrix.

[0100] Depend on Figure 9 It can be seen that the cross-section of the magnetic particle film in Example 3 clearly shows the lattice stripes of cobalt nanoparticles, indicating good particle crystallinity. The particles are spherical and their size can be maintained within the range of 10 nm, and they are relatively uniformly distributed in the cobalt magnetic particle injection layer of the magnetic particle film.

[0101] The low-temperature hysteresis loop diagram of the magnetic particle film in Example 3, measured at 20K, is shown below. Figure 10 As shown.

[0102] Depend on Figure 10 It can be seen that the magnetic particle film prepared after the differential processing and specific laser annealing process in Example 3 exhibits obvious magnetic hysteresis characteristics.

[0103] In summary, this invention combines metal vapor vacuum arc ion implantation technology with nanosecond laser annealing to prepare sub-10 nanometer magnetic particles. Magnetic nanoparticle films in the range of 1 to 10 nanometers play an important role in magnetic recording and magnetic sensing. This method has broad prospects in the research and preparation of particle films and even in the application of magnetic materials.

[0104] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for producing a magnetic particle film of magnetic particles having a particle size of < 10 nm, characterized by, The method comprises the following steps: 1) subjecting a quartz substrate to differential processing to obtain a quartz substrate having a plurality of equal-area region units; 2) selecting one side of a quartz substrate with several area units, and obtaining a magnetic particle film through a metal vapor vacuum arc ion implantation process and a laser annealing process, wherein the implantation dose of the metal vapor vacuum arc ion implantation is 2.5×10 17 cm -2 ; and 17 3.5×10 -2 cm -2 . Step 2) the parameters of the laser annealing process are set as follows: 1 pulse signal, the pulse signal has the following characteristics: delay time of 107 microseconds, single pulse energy of 42 millijoules; or, 1 pulse signal, the pulse signal has the following characteristics: delay time of 57 microseconds, single pulse energy of 142 millijoules; Step 2) The parameters of the metal vapor vacuum arc ion implantation are: vacuum degree 4x10 -4 ~6x10 -4 Pa, ion generation frequency 5-15 Hz, implantation energy fixed at 20-60 keV, and the target material of the ion source is cobalt material.

2. The method of claim 1, wherein: Step 1) the differential processing operation is: cutting into a cuboid by laser, and then drawing a scratch on the back of the quartz substrate by laser.

3. The method of claim 1, wherein: Step 2) the laser annealing process is: irradiating the ion implantation surface of the quartz substrate with discontinuous region units.

4. The method of claim 1, wherein: The area ratio of the region units of the quartz substrate to the area of the selected laser annealing beam spot is 1: (2-3.5).

5. A magnetic particle film prepared by the method of any one of claims 1 to 4.

6. The magnetic particle film of claim 5, wherein: The magnetic particle film comprises a quartz substrate layer and a cobalt magnetic particle implantation layer, and the cobalt particles in the cobalt magnetic particle implantation layer have a diameter of <10 nm.

7. The magnetic particle film of claim 6, wherein: The thickness of the cobalt magnetic particle implantation layer is 100 nm.

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