Magnetic powder based on MOF precursor and preparation method and application thereof
Through hydrothermal method and high-temperature calcination, the problems of existing magnetic powders in particle size control, particle aggregation and high-temperature stability are solved, and mass production with strong exchange bias and stability are achieved.
Patent Information
- Application Number
- CN202411953387.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-04-29
AI Technical Summary
The existing synthetic exchange biased magnetic powders have problems such as difficulty in controlling particle size, particle aggregation, and poor stability of exchange bias at high temperatures.
Magnetic powders with strong exchange bias were prepared by hydrothermal method and combined with high-temperature calcination. The method includes mixing an iron source, a platinum source, an organic ligand and a solvent, performing heat treatment to generate a precursor MOF material, washing, centrifugation, drying and grinding treatment, and finally calcining to obtain a magnetic powder.
Mass production with strong exchange bias and stability is achieved, and the magnetic powder is magnetic at room temperature and has a strong exchange bias field at low temperatures, and the floating of the exchange bias field is only about 10%.
Smart Images
Figure CN119905334A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of magnetic materials, and in particular to a magnetic powder based on an MOF precursor, and a preparation method and application thereof. Background Art
[0002] With the rapid development of information technology, especially in the fields of magnetic memory, magnetic sensors and spintronics, the performance of magnetic materials has become one of the key factors determining system performance. In these applications, magnetic materials need to have high magnetism, stability and response speed to meet the needs of modern electronic devices for high performance, low power and miniaturization.
[0003] Among them, the exchange bias effect, that is, the shift of magnetization direction caused by contact between ferromagnetic materials and antiferromagnetic materials at low temperature, has been widely used in magnetic storage, magnetic sensors, hard disk drives and other technologies. The exchange bias effect can make magnetic devices maintain higher stability under the action of external magnetic fields and improve the accuracy of read and write signals of magnetic heads or storage units. Therefore, it has been highly valued in the field of spin electronics.
[0004] At present, materials with room temperature magnetism and strong exchange bias mainly rely on more complex synthesis methods, such as high temperature annealing, sol-gel method, etc. However, these traditional methods often require a long synthesis process, high energy consumption and more complicated post-processing steps, resulting in high preparation costs. They usually require multi-step complex processes (such as sol-gel method, vapor deposition method, etc.), which are not only costly but also difficult to achieve large-scale production.
[0005] Therefore, the prior art still needs to be improved and developed. Summary of the invention
[0006] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a magnetic powder based on a MOF precursor and a preparation method and application thereof, aiming to solve the problems of difficulty in controlling particle size, particle aggregation and poor stability of exchange bias at high temperatures in the existing synthetic exchange bias magnetic powder.
[0007] The technical solution of the present invention is as follows:
[0008] A method for preparing magnetic powder based on MOF precursor comprises the following steps:
[0009] Mixing an iron source, a platinum source, an organic ligand and a solvent to obtain a mixture;
[0010] The mixture is subjected to heat treatment to obtain a precursor MOF material;
[0011] The precursor MOF material is washed, centrifuged and dried, and then ground and sieved to obtain precursor nanoparticles;
[0012] The precursor nanoparticles are calcined to obtain magnetic powder.
[0013] The method for preparing magnetic powder based on MOF precursor, wherein the iron source comprises Fe(ClO 4 )·XH 2 O, Fe(CH 3 COO 2 、Fe(NO 3 ) 3 9H 2 O, FeSO 4 One or more of; the platinum source includes PtCl 2 , K 2 PtCl 4 , H 2 PtCl 6 、Pt(NO 3 ) 2 , K 2 [Pt(CN) 4 ] one or more.
[0014] The method for preparing magnetic powder based on MOF precursor, wherein the organic ligand includes one or more of N,N'-bis(4-pyridyl)-1,4,5,8-naphthalenetetracarboxylic acid diimide, 2-methylimidazole, phthalic acid, 2,2'-bipyridine, 1,3,5-benzenetricarboxylic acid; and the solvent is water or a mixed solution of an organic solvent and water.
[0015] The method for preparing magnetic powder based on MOF precursor, wherein the molar ratio of the iron source, the platinum source and the organic ligand is 1:(4-6):(1-2).
[0016] The method for preparing magnetic powder based on MOF precursor, wherein the temperature of the heat treatment is 60-100° C., and the time of the heat treatment is 8-12 hours.
[0017] The method for preparing magnetic powder based on MOF precursor, wherein the rotation speed of the centrifugal treatment is 6500-9000r / min, the time of the centrifugal treatment is 3-5min, and the number of centrifugal treatments is not less than three times.
[0018] The method for preparing magnetic powder based on MOF precursor, wherein the temperature of the drying treatment is 50-70°C, the time of the drying treatment is 8-10h; and the mesh number of the grinding and sieving sieve is 180-200 meshes.
[0019] The method for preparing magnetic powder based on MOF precursor, wherein the temperature of the calcination treatment is 200-600°C, the time of the calcination treatment is 2-4h, and the heating rate of the calcination treatment is 5-10°C / min.
[0020] A magnetic powder based on an MOF precursor is prepared by using a preparation method of a magnetic powder based on an MOF precursor.
[0021] The invention discloses an application of magnetic powder based on MOF precursor in magnetic memory, magnetic sensor or magnetic random access memory.
[0022] Beneficial effects: The present invention provides a magnetic powder based on a MOF precursor and a preparation method and application thereof. The preparation method of the magnetic powder based on the MOF precursor comprises the steps of: mixing an iron source, a platinum source, an organic ligand and a solvent to obtain a mixture; heat-treating the mixture to obtain a precursor MOF material; washing, centrifuging and drying the precursor MOF material, grinding and screening to obtain precursor nanoparticles; calcining the precursor nanoparticles to obtain magnetic powder. The present invention synthesizes magnetic powder by a hydrothermal method, and combines a high-temperature calcination method to achieve the preparation of magnetic powder with strong exchange bias. The preparation method has the technical effect of simplifying the process and improving the performance. In addition, the magnetic powder obtained by the preparation method has magnetic conditions at room temperature and a strong exchange bias field at low temperature. At the same time, under the same conditions, a large amount of magnetic powder with consistent performance can be synthesized at the same time, and its magnetic properties are tested under 3 training effects, and the exchange bias field has only about 10% fluctuation, which proves that the magnetic powder obtained by the method has both room temperature magnetism and a stable and strong exchange bias field. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a process flow diagram of a method for preparing magnetic powder based on MOF precursor of the present invention;
[0024] Figure 2 is the X-ray diffraction pattern of the magnetic powder obtained in Example 1;
[0025] Figure 3 TEM image of the magnetic powder prepared in Example 1;
[0026] Figure 4 This is the energy spectrum analysis diagram of the magnetic powder prepared in Example 1;
[0027] Figure 5 This is the MH curve of the magnetic powder prepared in Example 1 obtained by testing in a comprehensive physical property measurement system. DETAILED DESCRIPTION
[0028] The present invention provides a magnetic powder based on a MOF precursor and a preparation method and application thereof. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.
[0029] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as herein.
[0030] The mechanism of powder exchange bias originates from the exchange interaction between ferromagnetic materials and antiferromagnetic materials. Simply put, when the two are in contact, the spin arrangement of the antiferromagnetic material affects the spin direction of the ferromagnetic material, causing the magnetization direction of the ferromagnetic material to shift. This effect is called exchange bias. Ferromagnetic materials have the same spin direction, while antiferromagnetic materials have opposite spin directions. This effect is more obvious at low temperatures because the spin arrangement of antiferromagnetic materials is more stable at low temperatures. Powders have a larger specific surface area and more interfaces, which enhances the exchange interaction between ferromagnetic materials and antiferromagnetic materials, resulting in a more significant exchange bias effect. At present, powders with exchange bias are widely used in devices such as magnetic memory, magnetic sensors, and magnetic random access memory (MRAM), using their strong exchange bias effect to improve the stability and performance of the devices. The current methods for synthesizing powder exchange bias include sol-gel method, coprecipitation method, mechanical alloying method and high-temperature solid phase method. Each method has certain challenges in particle size control, particle uniformity and temperature stability. The main problems include difficulty in particle size control, particle aggregation, poor stability of exchange bias at high temperatures, and high cost and production feasibility issues of some methods, which limit the performance optimization and practical application of powder exchange bias.
[0031] Based on this, Figure 1 As shown, the present invention provides a method for preparing magnetic powder based on MOF precursor, comprising the steps of:
[0032] Step S10: mixing an iron source, a platinum source, an organic ligand and a solvent to obtain a mixture;
[0033] Step S20: heat-treating the mixture to obtain a precursor MOF material;
[0034] Step S30: washing, centrifuging and drying the precursor MOF material, grinding and screening to obtain precursor nanoparticles;
[0035] Step S40: calcining the precursor nanoparticles to obtain magnetic powder.
[0036] In this embodiment, magnetic powder is synthesized by a hydrothermal method, and combined with a high-temperature calcination method, magnetic powder with strong exchange bias is prepared. The preparation method has the technical effect of simplifying the process and improving the performance. In addition, the magnetic powder prepared by the preparation method has magnetic conditions at room temperature and a strong exchange bias field at low temperature. At the same time, under the same conditions, a large amount of magnetic powder with consistent performance can be synthesized at the same time, and its magnetic properties fluctuate by only about 10% in the exchange bias field under 3 training effect tests, which proves that the magnetic powder prepared by this method has both room temperature magnetism and a stable and strong exchange bias field.
[0037] Specifically, hydrothermal synthesis is a technology that uses water as a solvent to synthesize materials under high temperature and high pressure conditions. The powder synthesized by hydrothermal method can have a strong exchange bias field. The reason why the magnetic material synthesized by hydrothermal method has a strong exchange bias field is mainly due to the combined effect of the following factors: First, the hydrothermal method can form a highly ordered structure on the surface or particle interface of the material. The interaction between ferromagnetism and antiferromagnetism on these interfaces (interface effect) often leads to changes in magnetic behavior, thereby enhancing the formation of exchange bias field; secondly, the nanoscale materials synthesized by hydrothermal method usually have a large specific surface area, which increases the surface energy. This surface effect is particularly significant in ferromagnetic / antiferromagnetic nanocomposites, which can further enhance the exchange bias effect; in addition, the particle size of the hydrothermal synthesized material is small and the crystallinity is high. The small particle size and high crystallinity often lead to strong interaction at the material interface, thereby strengthening the performance of the exchange bias field. Finally, the hydrothermal method uses water as a solvent and reacts under mild temperature and pressure conditions, which can effectively control the crystallization process of the material and obtain nanoscale powders with small particle size and uniform distribution. This method also has strong morphology control capabilities and adjustable reaction conditions (such as temperature, time, pH value, etc.), making the synthesized materials highly adjustable in crystal form, size and surface morphology, thus meeting different application requirements. At the same time, since the working temperature of the hydrothermal method is generally lower than that of other methods (80-180°C), this not only reduces the synthesis cost, but also avoids the thermal damage that the material may suffer during the synthesis process, and has high economy and sustainability.
[0038] In some embodiments, the iron source comprises Fe(ClO 4 )·XH 2 O, Fe(CH3 COO 2 、Fe(NO 3 ) 3 9H 2 O, FeSO 4 One or more of; the platinum source includes PtCl 2 , K 2 PtCl 4 , H 2 PtCl 6 、Pt(NO 3 ) 2 , K 2 [Pt(CN) 4 The above materials are used to provide iron and platinum elements to magnetic powders to synthesize metal oxides with exchange bias, and the exchange bias field has small fluctuation and high stability.
[0039] In some embodiments, the organic ligand includes one or more of N,N'-bis(4-pyridyl)-1,4,5,8-naphthalenetetracarboxylic acid diimide (DPNDI), 2-methylimidazole, phthalic acid (BDC), 2,2'-bipyridine (BIPY), and 1,3,5-benzenetricarboxylic acid (BTC); the solvent is water or a mixed solution of an organic solvent and water. The nitrogen atom of the organic ligand provides a coordination site to help the metal ions Fe and Pt form a stable metal-ligand bond, thereby constructing the framework structure of the MOF. The hydrothermal method uses water or a mixed solution of an organic solvent and water as a solvent, and reacts under mild temperature and pressure conditions, which can effectively control the crystallization process of the material and obtain nano-scale powders with small particle size and uniform distribution.
[0040] In some embodiments, the organic solvent includes, but is not limited to, one or more of methanol and ethanol.
[0041] In some embodiments, the molar ratio of the iron source, the platinum source and the organic ligand is 1:(4-6):(1-2). The molar ratio of the three solid reaction substrates is controlled within the above range, so that the reaction is complete and the waste of raw materials is avoided. At the same time, the molar ratio between the iron source, the platinum source and the organic ligand can be adjusted according to the demand for the exchange bias field strength of the magnetic powder, so as to achieve the purpose of regulating the magnitude of the exchange bias field of the magnetic powder.
[0042] In a preferred embodiment, the molar ratio of the iron source, the platinum source and the organic ligand is 1:5:1. In order to ensure that the reaction can generate a certain amount of product, the minimum feed amount of each reaction substrate is not less than 0.025 mmol (more than 5 mg).
[0043] In some embodiments, in step S10, the iron source, platinum source, organic ligand and solvent are mixed by ultrasonic mixing, magnetic stirring and vibration stirring. The iron source, platinum source, organic ligand and solvent are mixed by the above mixing method to form a uniformly dispersed mixture, which is beneficial to subsequent heat treatment. Preferably, the iron source, platinum source, organic ligand and solvent are mixed by magnetic stirring, which can better control the reaction temperature and avoid the influence of temperature on the material.
[0044] In some embodiments, in step S10, the time for mixing the iron source, platinum source, organic ligand and solvent is 15-30 minutes, so that the iron source, platinum source, organic ligand and solvent are mixed evenly without adding heat to the mixture, causing the temperature to affect the material.
[0045] In some embodiments, the heat treatment temperature is 60-100° C., and the heat treatment time is 8-12 hours, so that the mixture reacts at high temperature to generate a precursor MOF (metal organic framework) material.
[0046] In a preferred embodiment, the heat treatment temperature is 80° C. and the heat treatment time is 10 h.
[0047] In some embodiments, the centrifugal treatment speed is 6500-9000 r / min, the centrifugal treatment time is 3-5 min, and the number of centrifugal treatments is not less than three times. Centrifugal treatment can be used to remove unreacted raw materials in the precursor MOF material to obtain precursor nanoparticles with higher purity.
[0048] In some embodiments, the drying temperature is 50-70°C, the drying time is 8-10 hours, and the mesh size of the grinding and sieving is 180-200 meshes. The drying treatment is used to remove the solvent in the product after washing and centrifugation to obtain dry and high-purity precursor nanoparticles.
[0049] Specifically, in the step S30, the precursor MOF material is washed with methanol, centrifuged at a speed of 8000 r / min for 3 minutes, the supernatant is poured out, the above process is repeated three times, and the solid obtained by centrifugation is placed in a vacuum drying oven and dried at 60°C for 10 hours; the precursor powder obtained after drying is ground into powder with smaller particles, and then the powder is sieved through a 200-mesh sieve to ensure that the powder synthesized during the high-temperature heating process has a smaller particle size.
[0050] In some embodiments, the particle size of the precursor nanoparticles is between 10-20 nm.
[0051] In some embodiments, the calcination temperature is 200-600°C, the calcination time is 2-4h, and the heating rate is 5-10°C / min. Magnetic powders with metal oxide properties and strong exchange bias can be synthesized by calcination.
[0052] In a preferred embodiment, the calcination temperature is 550°C, the calcination time is 3 hours, and the heating rate of the calcination is 10°C / min.
[0053] In addition, the present invention also provides a magnetic powder based on a MOF precursor, which is prepared by using the preparation method of the magnetic powder based on a MOF precursor.
[0054] In this embodiment, the magnetic powder prepared by the preparation method has magnetic properties at room temperature and a strong exchange bias field at low temperature; at the same time, under the same conditions, a large amount of magnetic powder with consistent performance can be synthesized simultaneously, and its magnetic properties fluctuate by only about 10% in the exchange bias field under three training effect tests, proving that the magnetic powder prepared by this method has both room temperature magnetism and a stable and strong exchange bias field.
[0055] In addition, the present invention also provides an application of magnetic powder based on a MOF precursor in a magnetic memory, a magnetic sensor or a magnetic random access memory.
[0056] In this embodiment, the magnetic powder has a strong exchange bias field, and applying it to a magnetic memory, a magnetic sensor or a magnetic random access memory can improve the stability and performance of the device.
[0057] The following examples are further given to illustrate the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention belong to the scope of protection of the present invention.
[0058] Example 1
[0059] This embodiment prepares a magnetic powder based on a MOF precursor, comprising the following steps:
[0060] 1) Using a 30 ml polyvinyl chloride liner, add Fe(ClO 4 )·XH 2 O.K 2 [Pt(CN) 4], organic ligand DPNDI (N,N'-bis(4-pyridyl)-1,4,5,8-naphthalenetetracarboxylic acid diimide), and finally add 5 ml of methanol and 5 ml of water. After sealing the liner, put it into an ultrasonic bath for 30 minutes to mix the reactants evenly to obtain a mixture.
[0061] 2) The ultrasonic lining was placed in a reactor, the reactor was placed in an oven, and heated at 80° C. for 10 h to obtain a precursor MOF material.
[0062] 3) After the oven is cooled to room temperature, it is washed with methanol, centrifuged at a speed of 8000r / min for 3min, the supernatant is poured out, and the above process is repeated three times. The centrifuged solid is placed in a vacuum drying oven and dried at 60°C for 10h; then the obtained precursor powder is ground into powder with smaller particles, and the powder is sieved through a 200-mesh sieve to obtain precursor nanoparticles.
[0063] 4) Place the precursor nanoparticles in a small crucible with a capacity of 10 ml and spread it flat on the bottom to maximize its surface area with the outside world. Wrap the crucible with tin foil, poke a few small holes on it and place it in a muffle furnace. Raise the temperature from room temperature to 550°C at a rate of 10°C / min and keep it at this temperature for 3 hours. Finally, cool it naturally to room temperature and take it out of the muffle furnace to obtain powder, i.e., magnetic powder.
[0064] The magnetic powder obtained according to the above synthesis steps was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Figure 2 As shown in Figure 1, the results show that the magnetic powder is mainly composed of platinum (Pt) and iron (Fe) oxides. Figure 3 As shown in the figure, the powder has a flaky structure and nanoparticles with a size of 10-20 nm are distributed on the surface. Further energy spectrum analysis (EDS) is shown in the figure. Figure 4 As shown in the figure, it can be seen that Fe, Pt, C and N elements are evenly distributed in the magnetic powder. The material is tested for magnetic properties by a comprehensive physical property measurement system, and the obtained hysteresis loop (the relationship between magnetic field intensity and sample magnetization intensity) is shown in the figure below. Figure 5 As shown, it can be seen that the magnetic powder has a significant exchange bias effect, and the exchange bias field strength is about 1000 Oe.
[0065] Example 2
[0066] This embodiment prepares a magnetic powder based on a MOF precursor, comprising the following steps:
[0067] 1) Add a certain amount of FeSO into a 50ml beaker at a molar ratio of 1:5:1. 4 , H 2PtCl 6 , organic ligand 2-methylimidazole, and finally add 30 ml of methanol. After sealing the liner, put it into the ultrasonic pool for 30 minutes to mix the reactants evenly.
[0068] 2) The ultrasonic lining is placed in a reactor, the reactor is placed in an oven, and heated at 80° C. for 10 h to react at high temperature to generate a precursor MOF material.
[0069] 3) After the oven is cooled to room temperature, the mixture is washed with methanol and centrifuged at 8000 r / min for 3 min. The supernatant is discarded and the above process is repeated three times. The centrifuged solid is placed in a vacuum drying oven and dried at 60° for 10 h.
[0070] 4) Place the obtained powder directly into a small crucible with a capacity of 10 ml, spread it flat on the bottom, and maximize its surface area with the outside world. Wrap the crucible with tin foil, poke a few small holes on it, and place it into a muffle furnace. Raise the temperature from room temperature to 500°C at a rate of 5°C / min, and keep it at this temperature for 3 hours. Finally, cool it naturally to room temperature, and take it out of the muffle furnace to obtain the powder, i.e., the magnetic powder material.
[0071] The material was magnetically tested using a comprehensive physical property measurement system, and the hysteresis loop (the relationship between magnetic field intensity and sample magnetization intensity) obtained showed that the sample still had a certain exchange bias effect, and the exchange bias field strength was about 400Oe.
[0072] In summary, the present invention provides a magnetic powder based on MOF precursor and its preparation method and application, and a preparation method of magnetic powder with exchange bias, including the steps of: mixing an iron source, a platinum source, an organic ligand and a solvent to obtain a mixture; heat treating the mixture to obtain a precursor MOF material; washing, centrifuging and drying the precursor MOF material, grinding and screening to obtain precursor nanoparticles; calcining the precursor nanoparticles to obtain magnetic powder. The present invention synthesizes magnetic powder by hydrothermal method, and combines the method of high temperature calcination to achieve the preparation of magnetic powder with strong exchange bias. The preparation method has the technical effect of simplifying the process and improving the performance; in addition, the magnetic powder material prepared by the preparation method has magnetic conditions at room temperature and has a strong exchange bias field at low temperature; at the same time, under the same conditions, a large amount of magnetic powder with consistent performance can be synthesized at the same time, and its magnetic properties are tested under 3 training effects, and the exchange bias field has only about 10% fluctuation, which proves that the magnetic powder prepared by the method has both room temperature magnetism and stable and strong exchange bias field.
[0073] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.
Claims
1. A method for preparing magnetic powder based on MOF precursor, characterized in that: Includes steps: Mixing an iron source, a platinum source, an organic ligand and a solvent to obtain a mixture; The mixture is subjected to heat treatment to obtain a precursor MOF material; The precursor MOF material is washed, centrifuged and dried, and then ground and sieved to obtain precursor nanoparticles; The precursor nanoparticles are calcined to obtain magnetic powder.
2. The method for preparing magnetic powder based on MOF precursor according to claim 1, characterized in that: The iron source includes one or more of Fe(ClO4)·XH2O, Fe(CH3COO)2, Fe(NO3)3·9H2O, and FeSO4; the platinum source includes one or more of PtCl2, K2PtCl4, H2PtCl6, Pt(NO3)2, and K2[Pt(CN)4].
3. The method for preparing magnetic powder based on MOF precursor according to claim 1, characterized in that: The organic ligand includes one or more of N,N'-bis(4-pyridyl)-1,4,5,8-naphthalenetetracarboxylic acid diimide, 2-methylimidazole, phthalic acid, 2,2'-bipyridine, and 1,3,5-benzenetricarboxylic acid; the solvent is water or a mixed solution of an organic solvent and water.
4. The method for preparing magnetic powder based on MOF precursor according to claim 1, characterized in that: The molar ratio of the iron source, the platinum source and the organic ligand is 1:(4-6):(1-2).
5. The method for preparing magnetic powder based on MOF precursor according to claim 1, characterized in that: The temperature of the heat treatment is 60-100° C., and the time of the heat treatment is 8-12 hours.
6. The method for preparing magnetic powder based on MOF precursor according to claim 1, characterized in that: The rotation speed of the centrifugal treatment is 6500-9000 r / min, the time of the centrifugal treatment is 3-5 min, and the number of centrifugal treatments is not less than three times.
7. The method for preparing magnetic powder based on MOF precursor according to claim 1, characterized in that: The temperature of the drying treatment is 50-70° C., and the time of the drying treatment is 8-10 hours; the mesh number of the grinding and sieving is 180-200 meshes.
8. The method for preparing magnetic powder based on MOF precursor according to claim 1, characterized in that: The temperature of the calcination treatment is 200-600° C., the time of the calcination treatment is 2-4 hours, and the heating rate of the calcination treatment is 5-10° C. / min.
9. A magnetic powder based on a MOF precursor, characterized in that: The magnetic powder is prepared by the method for preparing the magnetic powder based on the MOF precursor as described in any one of claims 1 to 8.
10. Use of the magnetic powder based on the MOF precursor according to claim 9 in a magnetic memory, a magnetic sensor or a magnetic random access memory.