A cobalt ferrite nanometer magnetic material with high magnetic permeability and low loss and a preparation method thereof

Abstract

The application relates to a cobalt ferrite nanometer magnetic material with high magnetic permeability and low loss and a preparation method thereof, and belongs to the technical field of nanometer magnetic materials. The cobalt ferrite nanometer magnetic material with high magnetic permeability and low loss is mainly prepared from the following components: ferric chloride, cobalt chloride hexahydrate, manganese chloride, zinc sulfate, modified propylene glycol alginate acid ester, lithium chloride, silicon nitride and barium carbonate. The cobalt ferrite nanometer magnetic material prepared by the application has the characteristics of high magnetic permeability and low loss.

Description

Technical Field

[0001] The invention belongs to the technical field of nano-magnetic materials and relates to a cobalt ferrite nano-magnetic material with high magnetic permeability and low loss and a preparation method thereof. Background Art

[0002] Ferrite is a new type of non-metallic magnetic material. Compared to metallic magnetic materials, ferrite has advantages such as high resistivity, high dielectric properties, and high magnetic permeability at high frequencies. The main characteristic of ferrite magnetic materials is that their resistivity is much higher than that of metallic magnetic materials, which suppresses the generation of eddy currents and enables the magnetic properties of ferrite to be applied in high-frequency fields.

[0003] Cobalt ferrite is a magnetic material with specific electromagnetic, magnetic, and physical properties, and is widely used in electronics, communications, energy storage, and other fields. Among magnetic materials, cobalt ferrite is particularly prominent, exhibiting superior magnetic properties, stability, and corrosion resistance, thus holding a key position in the field of magnetic materials. In recent years, the preparation of magnetic nanomaterials has attracted increasing attention, and the development of high-performance magnetic nanomaterials has become a hot topic in magnetic materials research. Summary of the Invention

[0004] The main purpose of the present invention is to provide a cobalt ferrite and a preparation method thereof. The prepared cobalt ferrite has the characteristics of high magnetic permeability and low loss.

[0005] The present invention adopts the following technical solutions to achieve the above-mentioned purpose:

[0006] A cobalt ferrite nanomagnetic material with high magnetic permeability and low loss, mainly prepared from the following components:

[0007] Ferric chloride, cobalt chloride hexahydrate, manganese chloride, zinc sulfate, modified propylene glycol alginate, lithium chloride, silicon nitride, barium carbonate.

[0008] The preparation method of the magnetic material is:

[0009] S1. Add ferric chloride, cobalt chloride hexahydrate, manganese chloride, and zinc sulfate to water and stir at 40-50° C. to form a mixed solution, add tartaric acid or citric acid solution and mix well, add ammonia water, adjust the pH to 7.0-7.5, heat and react while stirring until a sol state is formed; dry the sol into a gel, and pre-calculate the mixture at the temperature to obtain a pre-calcined product;

[0010] S2. After grinding the pre-calcined product, modified propylene glycol alginate, silicon nitride, and barium carbonate are added and mixed. The mixture is kept at 800-900° C. for calcination for 2-3 hours, then cooled to 500-600° C. for calcination for 1-1.5 hours, cooled, ground for 1.5-2 hours, and sieved to obtain cobalt ferrite nanomagnetic material.

[0011] Preferably, in the above-mentioned preparation method S1, the mass-volume ratio of ferric chloride, cobalt chloride hexahydrate, manganese chloride, zinc sulfate, water, tartaric acid solution or citric acid solution is 10 in g / g / g / g / g / mL:(3-4):(1-1.5):(0.5-0.8):(8-12):(100-120).

[0012] Preferably, in the above preparation method S1, the concentration of the tartaric acid solution is 0.8 mol / L.

[0013] Preferably, in the above preparation method S1, the concentration of the citric acid solution is 0.5 mol / L.

[0014] Preferably, in the above preparation method S1, the heating reaction temperature is 70-80°C.

[0015] Preferably, in the above preparation method S1, the temperature of the heat preservation pre-calcination is 400-500° C. and the time is 1-1.5 h.

[0016] Preferably, in the above preparation method S1, the mass concentration of ammonia water is 20-25%.

[0017] Preferably, in the above-mentioned preparation method S2, the mass ratio of the calcined product, modified propylene glycol alginate, silicon nitride and barium carbonate is 100:(20-25):(5-8):(3-3.5).

[0018] As a preferred method, the preparation method of modified propylene glycol alginate is:

[0019] Propylene glycol alginate, mannitol, and tartaric acid are dissolved in water, heated to 50-60°C, stirred for 30-40 minutes, and then added to molten polyethylene glycol. The mixture is placed in an ice-water bath and stirred until it becomes viscous. Lithium chloride is slowly added during the stirring process to obtain modified propylene glycol alginate.

[0020] Further preferably, in the preparation of the above-mentioned modified propylene glycol alginate, the mass ratio of propylene glycol alginate, mannitol, tartaric acid, water, polyethylene glycol and lithium chloride is 10:(3-3.5):(5-8):(12-15):(10-15):(12-15).

[0021] More preferably, in the preparation of the modified propylene glycol alginate, the molecular weight of the polyethylene glycol is 600-1200.

[0022] The average particle size of the cobalt ferrite nano-magnetic material with high magnetic permeability and low loss prepared by the invention is 30-50 nm.

[0023] The present invention has the following beneficial effects:

[0024] 1. The method for preparing the cobalt ferrite nanomagnetic material of the present invention avoids the problem of easy agglomeration during the preparation of cobalt ferrite and effectively solves the problem of poor dispersibility of nanoparticles. The modified propylene glycol alginate added during the preparation process acts as both a binder and a stabilizer, thereby improving the uniformity and thermal stability of the nanomaterial, thereby reducing the loss of the magnetic material and improving the magnetic permeability.

[0025] 2. In the preparation process of cobalt ferrite nanomagnetic materials, the addition of auxiliary materials such as silicon nitride and barium carbonate can improve the magnetic permeability and resistivity of the material and reduce magnetic loss and eddy current loss.

[0026] 3. During the preparation process, the materials are ground and sintered multiple times to make them evenly mixed and obtain a uniform sintered body, so that the final nanomagnetic material has the characteristics of high magnetic permeability and low loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 : SEM images of different cobalt ferrite nanomagnetic materials, wherein A is the cobalt ferrite nanomagnetic material of Example 1, B is the cobalt ferrite nanomagnetic material of Comparative Example 1, C is the cobalt ferrite nanomagnetic material of Comparative Example 2, and D is the cobalt ferrite nanomagnetic material of Comparative Example 3. DETAILED DESCRIPTION

[0028] The present invention is further illustrated below with reference to specific examples. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, modifications of various equivalent forms of the present invention made by those skilled in the art all fall within the scope of protection of the claims of this application.

[0029] Example 1

[0030] Preparation of modified propylene glycol alginate:

[0031] Take 10g of polyethylene glycol 600 and heat it to a molten state; add 10g of propylene glycol alginate, 3.5g of mannitol, and 5g of tartaric acid to 15g of water, dissolve them by ultrasonication, heat to 60°C, stir for 30 minutes, then add to the molten polyethylene glycol, place in an ice water bath and stir until it becomes viscous, and slowly add 15g of lithium chloride during the stirring process to obtain modified propylene glycol alginate.

[0032] Preparation of magnetic materials:

[0033] S1. Take 10 g of ferric chloride, 4 g of cobalt chloride hexahydrate, 1 g of manganese chloride, and 0.8 g of zinc sulfate, add 8 g of water, and stir in a water bath at 50°C for 1.5 h to prepare a mixed solution. Then add 120 mL of 0.5 mol / L citric acid solution and mix well. Place on a magnetic stirrer and stir for 20 min. Add 20% ammonia water dropwise, adjust the pH to 7.0, increase the water bath temperature to 80°C, and stir until it forms a sol. Dry the sol at about 200°C to form a gel. Pre-calcine the gel at 500°C for 1 h to obtain a calcined product.

[0034] S2. Grind 100 g of the calcined product, add 20 g of the modified propylene glycol alginate, 8 g of silicon nitride, and 3 g of barium carbonate, mix well, and calcine at 900 ° C for 2 h, then cool to 500 ° C and calcine for 1.5 h, cool, grind for 2 h, and pass through a standard sieve to obtain a cobalt ferrite nanomagnetic material with an average particle size of about 50 nm.

[0035] Example 2

[0036] Preparation of modified propylene glycol alginate:

[0037] Take 15g of polyethylene glycol 1200 and heat it to a molten state; add 10g of propylene glycol alginate, 3g of mannitol, and 8g of tartaric acid to 12g of water, dissolve them by ultrasonication, heat to 50°C, stir for 40 minutes, and then add them to the molten polyethylene glycol. Place it in an ice water bath and stir until it becomes viscous. During the stirring process, slowly add 12g of lithium chloride to obtain modified propylene glycol alginate.

[0038] Preparation of magnetic materials:

[0039] S1. Take 10 g of ferric chloride, 3 g of cobalt chloride hexahydrate, 1.5 g of manganese chloride, and 0.5 g of zinc sulfate, add 12 g of water, and stir in a water bath at 40°C for 2 h to prepare a mixed solution. Then, add 100 mL of 0.8 mol / L tartaric acid solution and mix well. Place on a magnetic stirrer and stir for 15 min. Add 25% ammonia water dropwise, adjust the pH to 7.5, increase the water bath temperature to 70°C, and stir until it forms a sol. Dry the sol at about 200°C to form a gel. Pre-calcine the gel at 400°C for 1.5 h to obtain a calcined product.

[0040] S2. Grind 100 g of the calcined product, add 25 g of the modified propylene glycol alginate, 5 g of silicon nitride, and 3.5 g of barium carbonate, mix well, and calcine at 800 ° C for 3 h, then cool to 600 ° C and calcine for 1 h, cool, grind for 1.5 h, and pass through a standard sieve to obtain a cobalt ferrite nanomagnetic material with an average particle size of about 30 nm.

[0041] Example 3

[0042] Preparation of modified propylene glycol alginate:

[0043] Take 13g of polyethylene glycol 800 and heat it to a molten state; add 10g of propylene glycol alginate, 3.2g of mannitol, and 7g of tartaric acid to 13g of water, dissolve them by ultrasonication, heat to 60°C, stir for 35 minutes, and then add them to the molten polyethylene glycol. Place it in an ice water bath and stir until it becomes viscous. During the stirring process, slowly add 13g of lithium chloride to obtain modified propylene glycol alginate.

[0044] Preparation of magnetic materials:

[0045] S1. Take 10 g of ferric chloride, 4 g of cobalt chloride hexahydrate, 1 g of manganese chloride, and 0.6 g of zinc sulfate, add 10 g of water, and stir in a water bath at 50°C for 1.5 h to prepare a mixed solution. Then add 110 mL of 0.5 mol / L citric acid solution and mix well. Place on a magnetic stirrer and stir for 15 min. Add 25% ammonia water dropwise, adjust the pH to 7.5, increase the water bath temperature to 80°C, and stir until it forms a sol. Dry the sol at about 200°C to form a gel. Pre-calcine the gel at 500°C for 1 h to obtain a pre-calcined product.

[0046] S2. Grind 100 g of the calcined product, add 23 g of the modified propylene glycol alginate, 6 g of silicon nitride, and 3.2 g of barium carbonate, mix well, and calcine at 900 ° C for 2 h. Then cool to 600 ° C and calcine for 1 h. Cool, grind for 2 h, and pass through a standard sieve to obtain a cobalt ferrite nanomagnetic material with an average particle size of about 40 nm.

[0047] Example 4

[0048] Preparation of modified propylene glycol alginate:

[0049] Take 12g of polyethylene glycol 1000 and heat it to a molten state; add 15g of water to 10g of propylene glycol alginate, 3g of mannitol, and 6g of tartaric acid, dissolve them by ultrasonication, heat to 50°C, stir for 40 minutes, and then add them to the molten polyethylene glycol. Place it in an ice water bath and stir until it becomes viscous. During the stirring process, slowly add 14g of lithium chloride to obtain modified propylene glycol alginate.

[0050] Preparation of magnetic materials:

[0051] S1. Take 10 g of ferric chloride, 3 g of cobalt chloride hexahydrate, 1.5 g of manganese chloride, and 0.8 g of zinc sulfate, add 10 g of water, and stir in a water bath at 40°C for 2 h to prepare a mixed solution. Then, add 100 mL of 0.8 mol / L tartaric acid solution and mix well. Place on a magnetic stirrer and stir for 20 min. Add 20% ammonia water dropwise, adjust the pH to 7.0, increase the water bath temperature to 80°C, and stir until it forms a sol. Dry the sol at about 200°C to form a gel. Pre-calcine the gel at 400°C for 1.5 h to obtain a pre-calcined product.

[0052] S2. Grind 100 g of the calcined product, add 22 g of the modified propylene glycol alginate, 7 g of silicon nitride, and 3.5 g of barium carbonate, mix well, and calcine at 800 ° C for 3 h, then cool to 500 ° C and calcine for 1.5 h, cool, grind for 2 h, and pass through a standard sieve to obtain a cobalt ferrite nanomagnetic material with an average particle size of about 40 nm.

[0053] Comparative Example 1

[0054] 10 g of ferric chloride, 3 g of cobalt chloride hexahydrate, 1.5 g of manganese chloride, and 0.8 g of zinc sulfate were dissolved in 100 g of deionized water, stirred in a 60° C. water bath for 1 h, and then 120 mL of 0.5 mol / L citric acid solution was added. The mixture was placed on a magnetic stirrer and stirred at 300 r / min to obtain a mixed solution. 25% ammonia water was added dropwise to the mixture until the pH of the mixed solution reached 7.5. The water bath temperature was increased to 80° C. and stirring was continued until the mixed solution became a sol state. The obtained sol was dried at 200° C. to obtain a gel. The gel was calcined at 800° C. for 4 h, then discharged, ground for 2 h, and passed through a standard sieve to obtain a cobalt ferrite nanomagnetic material with an average particle size of about 50 nm.

[0055] Comparative Example 2

[0056] S1. Take 10 g of ferric chloride, 3 g of cobalt chloride hexahydrate, 1.5 g of manganese chloride, and 0.5 g of zinc sulfate, add 12 g of water, and stir in a water bath at 50°C for 1 hour to prepare a mixed solution. Then add 100 mL of 0.8 mol / L tartaric acid solution and mix well. Place on a magnetic stirrer and stir for 20 minutes. Add 25% ammonia water dropwise, adjust the pH to 7.5, increase the water bath temperature to 70°C and stir until it forms a sol; dry the sol at about 200°C to form a gel, and pre-calcine the gel at 400°C for 1.5 hours to obtain a calcined product;

[0057] S2. Grind 100 g of the calcined product, add 25 g of propylene glycol alginate and 8 g of silicon nitride, mix well, and calcine at 900 ° C for 2 h. Then cool to 600 ° C and calcine for 1 h. Cool, grind for 2 h, and pass through a standard sieve to obtain a cobalt ferrite nanomagnetic material with an average particle size of about 50 nm.

[0058] Comparative Example 3

[0059] Preparation of modified propylene glycol alginate:

[0060] Take 10g of polyethylene glycol 1000 and heat it to a molten state; add 12g of water to 10g of propylene glycol alginate, dissolve it by ultrasonication, heat it to 50-60℃, stir it for 30-40min, then add it to the molten polyethylene glycol, place it in an ice water bath and stir it until it becomes viscous, thereby obtaining modified propylene glycol alginate.

[0061] Preparation of magnetic materials:

[0062] S1. Take 10 g of ferric chloride, 4 g of cobalt chloride hexahydrate, 1 g of manganese chloride, and 0.8 g of zinc sulfate, add 12 g of water, and stir in a water bath at 50°C for 1 hour to prepare a mixed solution. Then add 120 mL of 0.5 mol / L citric acid solution and mix well. Place on a magnetic stirrer and stir for 15 minutes. Add 25% ammonia water dropwise, adjust the pH to 7.5, increase the water bath temperature to 80°C and stir until it forms a sol; dry the sol at about 200°C to form a gel, and pre-calcine the gel at 500°C for 1 hour to obtain a pre-calcined product;

[0063] S2. Grind 100 g of the calcined product, add 25 g of the modified propylene glycol alginate and 3 g of barium carbonate, mix well, calcine at 900 ° C for 2 h, then cool to 600 ° C and calcine for 1 h, cool, grind for 2 h, and pass through a standard sieve to obtain a cobalt ferrite nanomagnetic material with an average particle size of about 40 nm.

[0064] Comparative Example 4

[0065] Preparation of modified propylene glycol alginate:

[0066] Take 10g of polyethylene glycol 1000 and heat it to a molten state; add 10g of propylene glycol alginate, 3.5g of mannitol, and 5g of tartaric acid to 15g of water, dissolve them by ultrasonication, heat to 60°C, stir for 30 minutes, then add to the molten polyethylene glycol, place in an ice water bath and stir until it becomes viscous to obtain modified propylene glycol alginate.

[0067] Preparation of magnetic materials:

[0068] S1. Take 10 g of ferric chloride, 3 g of cobalt chloride hexahydrate, 1 g of manganese chloride, and 0.8 g of zinc sulfate, add 12 g of water, and stir in a water bath at 50°C for 1 hour to prepare a mixed solution. Then add 120 mL of 0.5 mol / L citric acid solution and mix well. Place on a magnetic stirrer and stir for 15 minutes. Add 25% ammonia water dropwise, adjust the pH to 7.0, increase the water bath temperature to 80°C, and stir until it forms a sol. Dry the sol at about 200°C to form a gel. Pre-calcine the gel at 500°C for 1 hour to obtain a pre-calcined product.

[0069] S2. Grind 100 g of the calcined product, add 25 g of the modified propylene glycol alginate and 3 g of barium carbonate, mix well, calcine at 900 ° C for 2 h, then cool to 600 ° C and calcine for 1 h, cool, grind for 2 h, and pass through a standard sieve to obtain a cobalt ferrite nanomagnetic material with an average particle size of about 40 nm.

[0070] Comparative Example 5

[0071] Preparation of modified propylene glycol alginate:

[0072] Take 12g of polyethylene glycol 1000 and heat it to a molten state; add 15g of water to 10g of propylene glycol alginate, 3g of mannitol, and 6g of tartaric acid, dissolve them by ultrasonication, heat to 50°C, stir for 40 minutes, and then add them to the molten polyethylene glycol. Place it in an ice water bath and stir until it becomes viscous. During the stirring process, slowly add 14g of lithium chloride to obtain modified propylene glycol alginate.

[0073] Preparation of magnetic materials:

[0074] 100 g of ferric chloride, 30 g of cobalt chloride hexahydrate, 15 g of manganese chloride, and 8 g of zinc sulfate were added to 100 g of water and stirred in a 40° C. water bath for 2 h to prepare a mixed solution. 1000 mL of 0.8 mol / L tartaric acid solution was then added and mixed. The mixture was placed on a magnetic stirrer and stirred for 20 min. 20% ammonia water was added dropwise to adjust the pH to 7.0. The water bath temperature was raised to 80° C. and stirred until a sol state was obtained. 22 g of the modified propylene glycol alginate, 7 g of silicon nitride, and 3.5 g of barium carbonate were added and mixed. The mixture was dried at about 200° C. to form a gel state. The gel was calcined at 800° C. for 4 h, cooled, ground for 2 h, and passed through a standard sieve to obtain a cobalt ferrite nanomagnetic material with an average particle size of about 40 nm.

[0075] Performance Testing

[0076] The nanomagnetic materials obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were subjected to performance tests in accordance with SJ20966-2006, and the results are shown in the calibration table.

[0077] Table 1 Test results

[0078]

[0079] As shown in Table 1, the nanomagnetic materials prepared in Examples 1 to 4 of the present invention have high magnetic permeability and low magnetic loss, and the loss is significantly reduced under high temperature and high frequency conditions. Comparative Example 1 is a traditional nanomagnetic material preparation method, and the magnetic permeability of the resulting nanomagnetic material is low and the gross loss is large; in Comparative Example 2, the propylene glycol alginate added is not modified and the preparation raw materials do not contain barium carbonate. Although the magnetic loss is reduced compared with Comparative Example 1, the electrical conductivity is reduced; in Comparative Example 3, the propylene glycol alginate modification method is different and the preparation raw materials do not contain silicon nitride. Compared with the examples, its electrical conductivity is low and the magnetic loss is high; in Comparative Example 4, lithium chloride is not added during the modification of propylene glycol alginate and silicon nitride is not contained in the preparation raw materials. Its electrical conductivity is slightly higher than that of Comparative Example 3 and its magnetic loss is lower than that of Comparative Example 3; the preparation method of the magnetic material in Comparative Example 5 is different from that of the present invention, and its electrical conductivity is significantly lower and its magnetic loss is higher. Overall, the performance of the nanomagnetic materials prepared in Comparative Examples 1 to 5 is inferior to that of the nanomagnetic materials prepared in the present invention. From the results in the attached figures, it can be seen that the cobalt ferrite nanomagnetic materials prepared by the present invention have uniform sizes, while the cobalt ferrite nanomagnetic materials prepared in Comparative Examples 1-3 have grain agglomeration to varying degrees.

Claims

1. A cobalt ferrite nanomagnetic material with high magnetic permeability and low loss, characterized in that: It is prepared from the following ingredients: ferric chloride, cobalt chloride hexahydrate, manganese chloride, zinc sulfate, modified propylene glycol alginate, lithium chloride, silicon nitride, and barium carbonate; The preparation method of the cobalt ferrite nanomagnetic material is: S1. Add ferric chloride, cobalt chloride hexahydrate, manganese chloride, and zinc sulfate to water and stir at 40-50° C. to form a mixed solution, add tartaric acid or citric acid solution and mix well, add ammonia water, adjust the pH to 7.0-7.5, heat and react while stirring until a sol state is formed; dry the sol into a gel, and pre-calculate the mixture at the temperature to obtain a pre-calcined product; S2, after grinding the calcined product, adding modified propylene glycol alginate, silicon nitride, and barium carbonate to mix, placing it at 800-900 ° C and calcining it for 2-3 hours, then cooling it to 500-600 ° C and calcining it for 1-1.5 hours, cooling it, grinding it for 1.5-2 hours, and sieving it to obtain a cobalt ferrite nanomagnetic material; The preparation method of the modified propylene glycol alginate is as follows: Propylene glycol alginate, mannitol, and tartaric acid are dissolved in water, heated to 50-60°C, stirred for 30-40 minutes, and then added to molten polyethylene glycol. The mixture is placed in an ice-water bath and stirred until it becomes viscous. Lithium chloride is slowly added during the stirring process to obtain modified propylene glycol alginate.

2. The cobalt ferrite nanomagnetic material according to claim 1, characterized in that: In the preparation method S1, the mass-volume ratio of ferric chloride, cobalt chloride hexahydrate, manganese chloride, zinc sulfate, water, and tartaric acid solution or citric acid solution is 10:(3-4):(1-1.5):(0.5-0.8):(8-12):(100-120) in g / g / g / g / g / mL.

3. The cobalt ferrite nanomagnetic material according to claim 1, characterized in that: In the preparation method S1, the concentration of the tartaric acid solution is 0.8 mol / L; the concentration of the citric acid solution is 0.5 mol / L.

4. The cobalt ferrite nanomagnetic material according to claim 1, characterized in that: In the preparation method S1, the heating reaction temperature is 70-80°C.

5. The cobalt ferrite nanomagnetic material according to claim 1, characterized in that: In the preparation method S1, the temperature of the heat preservation pre-calcination is 400-500° C. and the time is 1-1.5 hours.

6. The cobalt ferrite nanomagnetic material according to claim 1, characterized in that: In the preparation method S1, the mass concentration of ammonia water is 20-25%.

7. The cobalt ferrite nanomagnetic material according to claim 1, characterized in that: In the preparation method S2, the mass ratio of the calcined product, modified propylene glycol alginate, silicon nitride, and barium carbonate is 100:(20-25):(5-8):(3-3.5).

8. The cobalt ferrite nanomagnetic material according to claim 1, characterized in that: In the preparation method of the modified propylene glycol alginate, the mass ratio of propylene glycol alginate, mannitol, tartaric acid, water, polyethylene glycol, and lithium chloride is 10:(3-3.5):(5-8):(12-15):(10-15):(12-15).

9. The cobalt ferrite nanomagnetic material according to claim 1, characterized in that: The molecular weight of the polyethylene glycol in the preparation method of the modified propylene glycol alginate is 600-1200.

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