A parallel magnetic field device and a method for arranging one-dimensional magnetic materials over a large area thereof

Abstract

The present invention discloses a method for arranging one-dimensional magnetic materials over a large area in a solution, the key of which is the preparation of a large-area parallel magnetic field device. The method first utilizes a large-area parallel magnetic field device to orderly adsorb and arrange the one-dimensional magnetic materials dispersed in the solution on a desired substrate in the direction of the parallel magnetic field, and then removes the solution under certain conditions, thereby achieving a directional and orderly arrangement of the one-dimensional magnetic materials over a large area. The method of the present invention is not only simple to operate, the required device is easy to manufacture and low in cost, but also easy to arrange one-dimensional magnetic materials over a large area with controllable thickness on substrates of 4 inches or more. This large-area preparation method will greatly promote the large-scale, mass production of one-dimensional magnetic material micro-nano devices.

Description

Technical Field

[0001] The present invention belongs to the intersecting field of micro-nano device manufacturing, microelectronics technology and communication technology, and specifically relates to a parallel magnetic field device and a method for arranging one-dimensional magnetic materials over a large area. Background Art

[0002] With the advancement of nanotechnology, the fabrication of micro- and nanoelectronic devices has become increasingly sophisticated. One of the key processes lies in the orderly arrangement and assembly of one-dimensional nanomaterials. Consequently, the controllable preparation of nanowire arrays has attracted widespread attention. Once fabricated, these one-dimensional nanomaterials can be used in optical, optoelectronic, field-effect transistor, and sensor applications. In recent years, researchers have developed numerous methods for assembling one-dimensional nanomaterials, including Langmuir-Blodgett (LB) film, microfluidics, electric field-assisted methods, vacuum filtration, bubble blowing, selective chemical or biological pattern transcription, magnetic field-assisted methods, and optical trapping. While these methods have achieved significant progress, meeting the application requirements of nanodevices remains a significant gap, and the integrated assembly of nanomaterials remains a key challenge. It is important to note that two approaches have been reported for aligning one-dimensional magnetic nanomaterials in solvents using magnetic fields: directly using large permanent magnets and using permanent magnet arrays, such as Halbach arrays. Directly using permanent magnets to arrange one-dimensional magnetic nanomaterials can produce an ordered array structure, but due to the size limitation of the permanent magnets, the sample area produced is small and difficult to meet the needs of practical applications; the Halbach array can produce a large-area one-dimensional magnetic nanomaterial array, but the uneven magnetic field of the Halbach array causes the one-dimensional magnetic nanomaterial arrangement to be uneven. Summary of the Invention

[0003] The purpose of the present invention is to provide a parallel magnetic field device and a method for preparing large-area one-dimensional magnetic materials using the device. The method has simple process, low cost, and is easy to prepare micro-nano devices in large quantities.

[0004] The parallel magnetic field forming device provided by the present invention comprises a device bottom plate 1, two supporting bases 2, two fixed front baffles 3, two fixing frames 4, a magnetic conductive plate 5, a sliding groove 6, and two permanent magnets 7;

[0005] The two supporting bases 2 are located below the device base plate 1 and are used to support the device base plate 1; the two fixed front baffles 3, two fixing frames 4, and two permanent magnets 7 are all located on the device base plate 1, and one fixed front baffle 3 and one fixing frame 4 are used to fix one permanent magnet 7; one end of the device base plate 1 is provided with a sliding groove 6 for fixing the front baffle 3 and the fixing frame 4, which is convenient for adjusting the distance between the two permanent magnets 7, and the magnetic conductive plate 5 is provided between the two permanent magnets 7 and placed on the two fixed front baffles 3.

[0006] In the above device, the heights of the two supporting bases 2 are adjustable.

[0007] In the above device, the two fixed front baffles 3 are located on either side of the device base plate 1; the two fixing brackets 4 are located on either side of the device base plate 1; and the two permanent magnets 7 are located on either side of the device base plate 1, with their north and south poles facing each other and maintaining a certain distance. This distance is related to the length of the magnetic conductive plate 5.

[0008] In the above device, the two fixed front baffles 3 are located between the two permanent magnets 7 , and the two fixing frames 4 are located outside the two permanent magnets 7 .

[0009] When the one-dimensional magnetic nanomaterials are arranged on the parallel magnetic field forming device, it is necessary to adjust the support base 2 so that the surface of the magnetic conductive plate 5 remains horizontal.

[0010] When one-dimensional magnetic nanomaterials are arranged on a parallel magnetic field forming device, a container with a fixed substrate should be placed at the center of the magnetic conductive plate to ensure that the bottom of the container is in the parallel magnetic field.

[0011] The present invention also provides a method for preparing one-dimensional magnetic materials arranged over a large area by using the above device.

[0012] The method provided by the present invention for preparing a large-area one-dimensional magnetic material using the above-mentioned device comprises the following steps:

[0013] a) pre-treating the one-dimensional magnetic material, and then placing it in a solvent and ultrasonically dispersing it uniformly in the solvent to form a one-dimensional magnetic material suspension;

[0014] b) placing the substrate at the center of the bottom of the container, then placing the container at the center of the magnetic conductive plate of the parallel magnetic field forming device, and finally quickly pouring the one-dimensional magnetic material suspension prepared in step a) into the container and allowing it to stand. Under the action of gravity and parallel magnetic force, the one-dimensional magnetic material will fall and be orderly arranged on the substrate;

[0015] c) After the one-dimensional magnetic nanomaterial ordered array is formed, the solution in the container is evaporated and removed, and a large-area uniform and ordered one-dimensional magnetic material array can be prepared on the substrate.

[0016] In step a) of the above method, the one-dimensional magnetic material refers to a one-dimensional organic and / or inorganic nanomaterial (such as nanowires, etc.) with magnetism.

[0017] In step a) of the above method, pre-treating the one-dimensional magnetic material refers to increasing or eliminating the surface charge of the one-dimensional magnetic material, so that the one-dimensional magnetic material can be evenly dispersed in the solution.

[0018] In step a) of the above method, the solvent may be water, ethanol or a mixed solution of water and ethanol.

[0019] In step b) of the above method, there are no requirements for the shape of the container, and its size cannot be larger than that of the magnetic conductive plate.

[0020] In step b) of the above method, there is no specific requirement for the material of the substrate, and it can be a silicon, quartz, PC substrate, etc., and its size must be smaller than the size of the container.

[0021] In step b) of the above method, the substrate is directly placed on the bottom of the container and does not require external fixation.

[0022] In step b) of the above method, the standing time may be 5-30 minutes.

[0023] The method further comprises repeating the operations of steps a) to c) on the large-area uniformly ordered one-dimensional magnetic material array prepared in step c) to prepare at least one layer of large-area uniformly ordered one-dimensional magnetic material array.

[0024] When superimposing the preparation on the initially prepared large-area uniformly ordered one-dimensional magnetic material array, the radial direction of the existing one-dimensional magnetic material on the substrate and the direction of the parallel magnetic field can be changed by changing the center position of the culture dish with the substrate on the magnetic conductive plate (such as rotating it horizontally 90° counterclockwise), so that the radial direction of the one-dimensional magnetic material on the substrate and the direction of the parallel magnetic field are changed (such as rotating the culture dish horizontally 90° counterclockwise, the radial direction of the one-dimensional magnetic material is perpendicular to the direction of the parallel magnetic field), thereby making the radial direction of each layer of the prepared one-dimensional magnetic material array different.

[0025] The parallel magnetic field forming device is mainly assembled by permanent magnets and magnetic conductive plates according to a certain structure.

[0026] The present invention is based on the principle of arranging one-dimensional magnetic nanomaterials in parallel magnetic field over a large area. Figure 1 and devices such as Figure 2 As shown, the N and N poles of the two permanent magnets are opposite and maintain a certain distance. A magnetic plate is used to concentrate the magnetic field originally distributed in the air of the permanent magnets into the magnetic plate to form a large-area parallel magnetic field. When the evenly dispersed one-dimensional magnetic nanomaterial suspension is poured into a container placed in the center of the magnetic plate, the one-dimensional magnetic nanomaterial will be deposited at the bottom of the container under the action of the magnetic field force and gravity to form an ordered array. Finally, the solution in the container is removed. Due to the van der Waals force between the nanowires and the substrate, the nanowires will be well adsorbed on the substrate, thereby preparing a large-area one-dimensional magnetic nanomaterial ordered array.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1) The device required by the present invention is simple, easy to operate and controllable, and easy to design and manufacture;

[0029] 2) The arrangement method of the present invention can easily achieve the regulation of the thickness of one-dimensional magnetic materials and the arrangement of multiple layers;

[0030] 3) The parallel magnetic field forming device of the present invention can adjust the distribution of the parallel magnetic field by changing the spacing of the permanent magnets and the size of the magnetic conductive plate to meet the preparation requirements of different one-dimensional magnetic nanomaterials and samples of different areas;

[0031] 4) The present invention can produce large-area uniform and ordered one-dimensional magnetic nanomaterial arrays, which can be used to prepare micro-nanoelectronic, optoelectronic and electromagnetic wave protection devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the arrangement of one-dimensional magnetic nanomaterials in a parallel magnetic field in the present invention, which includes: a magnetic conductive plate 5, a one-dimensional magnetic nanomaterial suspension 8, a glass container 9 and a substrate 10.

[0033] Figure 2 This is a schematic diagram of a parallel magnetic field forming device, where the markings are as follows: 1 device base plate, 2 support base, 3 fixed front baffle, 4 fixing frame, 5 magnetic conductive plate, 6 sliding groove, 7 permanent magnet.

[0034] Figure 3 This is a photo of a large-area arranged single-layer Ni nanowire array prepared in Example 3.

[0035] Figure 4 This is a photograph of a large-area double-layer orthogonal Ni nanowire array prepared in Example 4. DETAILED DESCRIPTION

[0036] The present invention is further described below with reference to specific examples, but the present invention is not limited to the following examples. The methods described are conventional methods unless otherwise specified. The raw materials described can be obtained from public commercial channels unless otherwise specified.

[0037] Example 1: Parallel magnetic field forming device

[0038] like Figure 2The parallel magnetic field forming device provided by the present invention includes a device base 1, two supporting bases 2, two fixed front baffles 3, two fixing frames 4, a magnetic conductive plate 5, a sliding groove 6, and two permanent magnets 7; the two supporting bases 2 are located below the device base 1 and are used to support the device base 1; the two fixed front baffles 3, two fixing frames 4, and two permanent magnets 7 are all located on the device base 1, and one fixed front baffle 3 and one fixing frame 4 are used to fix one permanent magnet 7; one end of the device base 1 is provided with a sliding groove 6 for fixing the front baffle 3 and the fixing frame 4, which is convenient for adjusting the distance between the two permanent magnets 7, and the magnetic conductive plate 5 is arranged between the two permanent magnets 7 and placed on the two fixed front baffles 3.

[0039] Furthermore, the two fixed front baffles 3 are located between the two permanent magnets 7 , and the two fixing frames 4 are located outside the two permanent magnets 7 .

[0040] When the one-dimensional magnetic nanomaterials are arranged on the parallel magnetic field forming device, it is necessary to adjust the support base 2 so that the surface of the magnetic conductive plate 5 remains horizontal.

[0041] When one-dimensional magnetic nanomaterials are arranged on a parallel magnetic field forming device, a container with a fixed substrate should be placed at the center of the magnetic conductive plate to ensure that the bottom of the container is in the parallel magnetic field.

[0042] Example 2: Preparation of large-area one-dimensional magnetic materials using a parallel magnetic field forming device

[0043] A method for arranging one-dimensional magnetic nanomaterials using a large-area parallel magnetic field forming device comprises the following steps:

[0044] (1) placing one-dimensional magnetic nanomaterials into a solution and ultrasonically dispersing them to form a uniformly distributed nanomaterial suspension;

[0045] (2) placing a container with a substrate at the bottom at the center of the magnetic conductive plate of the parallel magnetic field forming device, and then quickly pouring the nanowire suspension into the container and letting it stand;

[0046] (3) Under the action of gravity and parallel magnetic field force, the one-dimensional magnetic nanomaterials will fall and be arranged in an orderly manner on the substrate at the bottom of the container;

[0047] (4) After the one-dimensional magnetic nanomaterial ordered array is formed, the solution in the container is removed to obtain a large-area one-dimensional magnetic material ordered array on the substrate.

[0048] The present invention is based on the principle of arranging one-dimensional magnetic nanomaterials in parallel magnetic field over a large area. Figure 1 and devices such as Figure 2As shown, the N and N poles of the two permanent magnets are opposite and maintain a certain distance. A magnetic plate is used to concentrate the magnetic field originally distributed in the air of the permanent magnets into the magnetic plate to form a large-area parallel magnetic field. When the evenly dispersed one-dimensional magnetic nanomaterial suspension is poured into a container placed in the center of the magnetic plate, the one-dimensional magnetic nanomaterial will be deposited at the bottom of the container under the action of the magnetic field force and gravity to form an ordered array. Finally, the solution in the container is removed. Due to the van der Waals force between the nanowires and the substrate, the nanowires will be well adsorbed on the substrate, thereby preparing a large-area one-dimensional magnetic nanomaterial ordered array.

[0049] Example 3: Preparation of large-area single-layer Ni nanowire arrays using a parallel magnetic field forming device

[0050] Nickel nanowires with a diameter of 300 nm and a length of 20 μm (preparation method reference: Xiang, WF; Zhang, JQ; Liu, Y.; etc. "Facile controlled synthesis and magnetic properties of high-aspectratio nickel nanowires prepared by the dropping method," J. Alloy. Compd. 693, 2017, pp. 257-263) were repeatedly washed with deionized water and ethanol, then immersed in a 10% hexadecyltrimethylammonium bromide aqueous solution and dried. Finally, an ultrasonic machine was used to uniformly disperse the nickel nanowires in ethanol to form a suspension.

[0051] In a large-area parallel magnetic field forming device, a neodymium iron boron permanent magnet with a length, width and height of 3cm×3cm×3cm and an iron plate with a length, width and height of 30cm×30cm×1cm are assembled as a magnetic conductive plate.

[0052] A 4-inch silicon substrate was fixed to the bottom of a 12cm diameter culture dish, and then the culture dish was placed in the center of the magnetic plate in the parallel magnetic field forming device. The dispersed Ni nanowire suspension was quickly poured into the culture dish and allowed to stand for 10 minutes. The device was then heated to 60°C and dried for 6 hours. Once the aqueous solution evaporated, an ordered array of nickel nanowires was prepared on the silicon substrate. The results are shown in Figure 2. Figure 3 shown.

[0053] Example 4: Preparation of a large-area double-layer orthogonal Ni nanowire array using a parallel magnetic field forming device

[0054] Ni nanowires with a diameter of 200 nm and a length of 40 μm were repeatedly washed with deionized water and ethanol, then immersed in a 10% hexadecyltrimethylammonium bromide aqueous solution and dried. Finally, an ultrasonic machine was used to uniformly disperse the nanowires in the ethanol to form a suspension.

[0055] In a large-area parallel magnetic field forming device, a neodymium iron boron permanent magnet with a length, width and height of 3cm×3cm×3cm and an iron plate with a length, width and height of 30cm×30cm×1cm are assembled as a magnetic conductive plate.

[0056] Fix a 4-inch silicon substrate to the bottom of a culture dish with a diameter of 12 cm, then place the culture dish at the center of the magnetic conductive plate in the parallel magnetic field forming device, quickly pour the dispersed Ni nanowire suspension into the culture dish and let it stand for 10 minutes, then heat the device to 60°C and dry it for 6 hours. After the aqueous solution evaporates, an ordered array of Ni nanowires can be prepared on the silicon substrate.

[0057] The culture dish with the substrate was then rotated 90° counterclockwise horizontally at the center of the magnetic plate so that the radial direction of the Ni nanowires on the substrate was perpendicular to the direction of the parallel magnetic field. The dispersed Ni nanowire suspension was then quickly poured into the culture dish and allowed to stand for 10 minutes. Finally, the device was heated to 60°C and dried for 6 hours to remove the aqueous solution in the container. A double-layer orthogonal Ni nanowire array was then prepared on the substrate. The results are shown in Figure 2. Figure 4 shown.

Claims

1. A method for preparing a large-area one-dimensional magnetic material array using a parallel magnetic field forming device, characterized in that: The parallel magnetic field forming device is composed of a device bottom plate, two supporting bases, two fixed front baffles, two fixing frames, a magnetic conductive plate, a sliding groove and two permanent magnets; The two supporting bases are located below the bottom plate of the device and are used to support the bottom plate of the device; the two fixed front baffles, two fixing frames, and two permanent magnets are all located on the bottom plate of the device, and one fixed front baffle and one fixing frame are used to fix one permanent magnet; one end of the bottom plate of the device is provided with a sliding groove for fixing the front baffle and the fixing frame, so as to facilitate adjustment of the distance between the two permanent magnets, and the magnetic conductive plate is provided between the two permanent magnets and placed on the two fixed front baffles; The two fixed front baffles are located on both sides of the device bottom plate; the two fixing frames are located on both sides of the device bottom plate; the two permanent magnets are located on both sides of the device bottom plate, and the N and S poles of the two permanent magnets are opposite and maintain a certain distance; The two fixed front baffles are located between the two permanent magnets, and the two fixing frames are located outside the two permanent magnets; The length, width and height of the permanent magnet are 3 cm × 3 cm × 3 cm; The length, width and height of the magnetic conductive plate are 30 cm × 30 cm × 1 cm; The method comprises the following steps: a) pre-treating the one-dimensional magnetic material, and then placing it in a solvent and ultrasonically dispersing it uniformly in the solvent to form a one-dimensional magnetic material suspension; b) placing the substrate at the center of the bottom of the container, then placing the container at the center of the magnetic conductive plate of the parallel magnetic field forming device, and finally quickly pouring the one-dimensional magnetic nanomaterial suspension prepared in step a) into the container and allowing it to stand. Under the action of gravity and parallel magnetic force, the one-dimensional magnetic material will fall and be orderly arranged on the substrate; c) After the one-dimensional magnetic material ordered array is formed, the solution in the container is evaporated and removed, and a large-area uniform and ordered one-dimensional magnetic material array can be prepared on the substrate.

2. The method according to claim 1, wherein: The heights of the two supporting bases are adjustable.

3. The method according to claim 1, wherein: In the step a), the one-dimensional magnetic material refers to a one-dimensional organic and / or inorganic nanomaterial with magnetism.

4. The method according to claim 1, wherein: In the step a), pre-treating the one-dimensional magnetic material refers to increasing or eliminating the surface charge of the one-dimensional magnetic material so that the one-dimensional magnetic material is uniformly dispersed in the solution.

5. The method according to claim 1, wherein: The method further comprises repeating the operations of steps a) to c) on the large-area uniformly ordered one-dimensional magnetic material array prepared in step c) to stack and prepare at least one layer of large-area uniformly ordered one-dimensional magnetic material array.

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