A binary spinel ferrite and a preparation method thereof

Abstract

The present invention relates to the technical field of magnetic materials. Specifically, it relates to a binary spinel ferrite and a preparation method thereof. The preparation method of the binary spinel ferrite comprises the following steps: adding a precipitant solution to a mixed material containing a first solvent, a second solvent, water, iron element and two other metal elements other than iron, and carrying out a reaction. After the reaction is completed, solid-liquid separation is carried out to obtain a precursor; after the precursor is calcined, a binary spinel ferrite is obtained; the first solvent includes choline chloride; the second solvent includes at least one of ethylene glycol, glycerol and urea; the other metal elements include two of Mg, Ni, Co and Zn elements. The binary spinel ferrite prepared by this method has high static magnetic properties, large size and high stability.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic materials, and in particular, to a binary spinel ferrite and a preparation method thereof. Background Art

[0002] As an excellent magnetic material, binary spinel ferrite materials have been widely used in power transformers, filters, sensors and other fields. At present, the preparation methods of binary spinel include: sol-gel method, hydrothermal method, chemical co-precipitation method, etc. Among them, the chemical co-precipitation reaction process is simple, easy to control, and the generated particle morphology is relatively complete, and the raw material sources are extensive, which is conducive to industrial production.

[0003] However, the existing chemical co-precipitation method uses metal ions and a precipitant to carry out a co-precipitation reaction in a solution to prepare a precursor, which is subjected to aging and filtration, and then high-temperature calcination, and finally the final product is obtained after grinding. The traditional chemical co-precipitation method has many disadvantages, such as the colloidal precipitate is difficult to filter, impurities are introduced, and particles are easily agglomerated during washing and drying. This will lead to low static magnetic properties and poor stability of the prepared binary spinel ferrite material.

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] The first object of the present invention is to provide a preparation method of a binary spinel ferrite. The present invention uses a eutectic solvent mixed with water to replace the traditional water solvent, and adopts the chemical co-precipitation method to prepare the binary spinel ferrite, which can improve the phenomenon of easy agglomeration of particles during the preparation of the precursor by the chemical co-precipitation method, and further improve its static magnetic properties and stability.

[0006] The second object of the present invention is to provide a binary spinel ferrite.

[0007] In order to achieve the above objects of the present invention, the following technical solutions are specifically adopted:

[0008] The present invention first provides a preparation method of a binary spinel ferrite, including the following steps:

[0009] Adding a precipitant solution to a mixed material containing a first solvent, a second solvent, water, iron element and other metal elements, and carrying out a reaction. After the reaction is completed, solid-liquid separation is carried out to obtain a precursor;

[0010] After the precursor is calcined, the binary spinel ferrite is obtained;

[0011] Wherein, the first solvent includes choline chloride;

[0012] The second solvent includes at least one of ethylene glycol, glycerol and urea;

[0013] The other metal elements include two of Mg, Ni, Co, and Zn elements.

[0014] The present invention further provides a binary spinel ferrite prepared by the preparation method of the binary spinel ferrite;

[0015] The chemical formula of the binary spinel ferrite is A x M 1-x Fe₂O₄, where 0 < x < 1, A and M are each independently selected from one of Mg, Ni, Co, and Zn elements, and A and M are different elements.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] (1) The preparation method of the binary spinel ferrite provided by the present invention can improve the phenomenon of easy aggregation of particles during the preparation of the precursor by the chemical coprecipitation method, thereby enhancing its static magnetic properties and stability, and reducing the coercivity.

[0018] (2) The preparation method of the binary spinel ferrite provided by the present invention can reduce the synthesis temperature: Using a deep eutectic solvent can reduce the synthesis temperature of metal oxide materials, which helps to save energy and improve production efficiency. Since the melting point of the deep eutectic mixture is usually low, the reaction can be completed at a lower temperature, thereby reducing heat loss and heating time.

[0019] (3) The preparation method of the binary spinel ferrite provided by the present invention can regulate the grain morphology and size: The special properties of the deep eutectic solvent, such as its influence on crystal growth and its dissolution performance for metal ions, can regulate the grain morphology and size of metal oxide materials to a certain extent, such as particle size, shape, and distribution.

[0020] (4) The preparation method of the binary spinel ferrite provided by the present invention can improve the crystal purity: The deep eutectic solvent can reduce the formation of impurities and crystal defects to a certain extent, which is beneficial to improving the purity and crystal quality of the product. Description of the Drawings

[0021] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is the XRD pattern of the binary spinel ferrite prepared in Example 2 provided by the present invention;

[0023] Figure 2 XRD pattern of the binary spinel ferrite prepared in Example 3 provided by the present invention;

[0024] Figure 3 VSM pattern of the binary spinel ferrite prepared in Example 2 provided by the present invention;

[0025] Figure 4 VSM pattern of the binary spinel ferrite prepared in Example 3 provided by the present invention;

[0026] Figure 5 XRD pattern of the binary spinel ferrite prepared in Example 4 provided by the present invention;

[0027] Figure 6 XRD pattern of the binary spinel ferrite prepared in Example 5 provided by the present invention;

[0028] Figure 7 XRD pattern of the binary spinel ferrite prepared in Example 6 provided by the present invention;

[0029] Figure 8 XRD pattern of the binary spinel ferrite prepared in Example 7 provided by the present invention;

[0030] Figure 9 XRD pattern of the binary spinel ferrite prepared in Example 8 provided by the present invention. Detailed implementation manners

[0031] The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific implementation manners. However, those skilled in the art will understand that the following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. For those conditions not specified in the embodiments, they shall be carried out according to conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments without indicating the manufacturer can be obtained as conventional products through commercial purchase.

[0032] If there is no special description, in the present invention, "the first aspect", "the second aspect", "the third aspect", "the fourth aspect", etc. are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or quantity, nor can it be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "the first", "the second", "the third", "the fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on the quantity.

[0033] Unless otherwise specified, the terms "comprising" and "including" mentioned in the present invention are open-ended and can also be closed-ended. For example, the terms "comprising" and "including" can mean that other components not listed can also be included or contained, or only the listed components are included or contained.

[0034] Unless otherwise specified, in the present invention, "one or more" or "at least one" refers to any one, any two, or any two or more of the listed items. Among them, "several" refers to any two or more.

[0035] In a first aspect, the present invention provides a method for preparing a binary spinel ferrite, comprising the following steps:

[0036] Adding a precipitant solution to a mixed material containing a first solvent, a second solvent, water, iron element, and other metal elements, and reacting. After the reaction is completed, solid-liquid separation is carried out to obtain a precursor.

[0037] Calcining the precursor, and after cooling, obtaining the binary spinel ferrite.

[0038] Among them, the first solvent includes choline chloride.

[0039] The second solvent includes at least one of ethylene glycol, glycerol, and urea.

[0040] Deep eutectic solvent is a green solvent, and its advantages in the process of preparing binary spinel ferrite include: deep eutectic solvent is completely miscible with water, metal salts can be well dissolved and dispersed in the mixed solution of deep eutectic solvent and water; nucleation occurs more uniformly during the precipitation process, weakening the agglomeration phenomenon of the precipitate and making the precursor particles finer; the fine and uniform particles in the precursor are conducive to accelerating the intermediate phase reaction occurring during the calcination process of the precursor, so the reaction temperature can be reduced or binary spinel ferrite with larger particle size can be obtained.

[0041] The other metal elements include two of Mg element, Ni element, Co element, and Zn element.

[0042] The molar ratio of the iron element to the other metal elements is 1.8 - 2.2:1, including but not limited to the point values of any one of 1.8:1, 1.9:1, 2:1, 2.1:1, 2.2:1 or the range values between any two of them.

[0043] By using specific types of the first solvent, the second solvent, and water as solvents, the present invention can make the precipitate more uniformly dispersed during the coprecipitation reaction process, thereby reducing the synthesis temperature, reducing energy consumption, and improving the magnetism, size, and stability of the binary spinel ferrite, and reducing its coercivity.

[0044] A lower coercivity indicates that the material is very sensitive to the magnetic field. This high sensitivity has important applications in fields such as magnetic sensors and magnetic memories, which can improve the performance and stability of devices. Moreover, a low coercivity means that less energy input is required to generate the desired magnetization, which is particularly important for some applications that require frequent magnetization reversals (such as magnetic memories).

[0045] Furthermore, the binary spinel ferrite prepared by the above method contains, in addition to iron element, two different other metal elements. By introducing two other metal elements, the spinel structure can be distorted, thereby obtaining different structural parameters and different physical properties, such as saturation magnetization, remanent magnetization, coercivity, conductivity, etc. Research shows that doping can improve the physical and chemical properties of the material, making it suitable for many important applications.

[0046] In some specific embodiments, the binary spinel ferrite can be prepared by the above method, that is, the spinel ferrite contains, in addition to iron element, two different metal elements. Binary spinel ferrites include, for example, nickel-zinc ferrite, cobalt-zinc ferrite, and magnesium-cobalt ferrite, but are not limited thereto.

[0047] In some specific embodiments, the binary spinel ferrite includes at least one of nickel-zinc ferrite, magnesium-cobalt ferrite, cobalt-zinc ferrite, magnesium-nickel ferrite, magnesium-zinc ferrite, and nickel-cobalt ferrite.

[0048] In some specific embodiments, the other metal elements include two of Mg, Ni, Co, and Zn elements, and the molar ratio of any two other metal elements is 0.1-0.9:0.1-0.9, such as 0.1:0.9, 0.2:0.8, 0.3:0.7, 0.4:0.6, 0.5:0.5, 0.6:0.4, 0.7:0.3, 0.8:0.2, or 0.9:0.1, but are not limited thereto.

[0049] In some specific embodiments, in the mixed material, the molar ratio of the first solvent to the second solvent is 0.8-1.2:1.8-2.2, including but not limited to any point value of 0.8:1.8, 1:1.8, 1.2:1.8, 0.8:2, 1:2, 1.2:2, 0.8:2.2, 1:2.2, 1.2:2.2 or the range value between any two of them.

[0050] In some specific embodiments, in the mixed material, the ratio of the sum of the volumes of the first solvent and the second solvent to the volume of water is 10 to 90:90 to 10, including but not limited to any point value among 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10 or the range value between any two of them.

[0051] In some specific embodiments, during the reaction, the pH value of the mixed material is 10 to 13, including but not limited to any point value among 10, 10.5, 11, 11.5, 12, 12.5, 13 or the range value between any two of them.

[0052] In some specific embodiments, the temperature of the reaction is 30 to 80 °C; including but not limited to any point value among 30 °C, 40 °C, 50 °C, 60 °C, 70 °C, 80 °C or the range value between any two of them.

[0053] In some specific embodiments, the reaction time is ≥ 0.5 h, including but not limited to any point value among 1 h, 2 h, 3 h, 4 h, 5 h, 8 h, 10 h, 12 h, 15 h, 18 h, 20 h, 24 h or the range value between any two of them.

[0054] In some specific embodiments, the calcination temperature is 400 to 800 °C; including but not limited to any point value among 400 °C, 500 °C, 600 °C, 700 °C, 800 °C or the range value between any two of them.

[0055] In some specific embodiments, the calcination time is ≥ 0.5 h, including but not limited to any point value among 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, 8 h, 10 h, 12 h, 15 h, 18 h, 20 h, 24 h or the range value between any two of them.

[0056] In some specific embodiments, the precipitant solution includes a sodium hydroxide solution.

[0057] In a second aspect, the present invention provides a binary spinel ferrite prepared by using the preparation method of the binary spinel ferrite.

[0058] Among them, the chemical formula of the binary spinel ferrite is A x M 1-x Fe2O4.

[0059] Among them, 0 < x < 1, A and M are each independently selected from one of the elements Mg, Ni, Co, and Zn, and A and M are different elements.

[0060] The binary spinel ferrite provided by the present invention has high magnetism and stability.

[0061] In some specific embodiments, the saturation magnetization of the binary spinel ferrite is ≥55 emu / g, including but not limited to the point values of any one of 55 emu / g, 56 emu / g, 57 emu / g, 58 emu / g, 59 emu / g, 60 emu / g, 61 emu / g, 62 emu / g, 63 emu / g, 65 emu / g, 68 emu / g, 70 emu / g or the range values between any two of them.

[0062] In some specific embodiments, the coercivity of the binary spinel ferrite is ≤55 Oe, including but not limited to the point values of any one of 55 Oe, 53 Oe, 51 Oe, 50 Oe, 48 Oe, 45 Oe or the range values between any two of them.

[0063] The binary spinel ferrite provided by the present invention can be used in the technical field of magnetic materials, such as applied in electronic fields such as power transformers, filters, sensors, etc., communication fields such as power electronics, fuel cells, solar cells, etc., or medical fields such as magnetic resonance imaging (MRI) devices, etc., but not limited thereto.

[0064] The implementation scheme of the present invention will be described in detail below in conjunction with the embodiments. However, those skilled in the art will understand that the following embodiments are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. For those not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified in the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0065] Example 1

[0066] The preparation method of the binary spinel ferrite provided in this embodiment includes the following steps:

[0067] Mix choline chloride and ethylene glycol according to a molar ratio of 1:2 and stir evenly to obtain a choline chloride-ethylene glycol solution. Mix the choline chloride-ethylene glycol solution with water according to a volume ratio of 10:90 and stir until the mixture is clear.

[0068] Mix 30 mL of the mixture with 2 mol of iron nitrate, 0.5 mol of nickel nitrate and 0.5 mol of zinc nitrate weighed and stir evenly to obtain a mixed salt solution.

[0069] Transfer the mixed salt solution into a reactor at 40 °C. Under continuous stirring, gradually add the sodium hydroxide solution dropwise to the mixed salt solution for coprecipitation reaction. After the pH of the reaction solution reaches 12, stop adding the sodium hydroxide solution and continue stirring the reaction for 1 h. End the reaction, filter the precipitate in the reactor, wash it with water until it is nearly neutral, then dry and grind it to obtain the precursor.

[0070] Calcine the precursor at 800 °C for 3 h to obtain the binary spinel ferrite.

[0071] The binary spinel ferrite prepared in this example is nickel-zinc ferrite.

[0072] Example 2

[0073] The preparation method of the binary spinel ferrite provided in this example is basically the same as that in Example 2, except that the volume ratio of the choline chloride-ethylene glycol solution to water is replaced with 25:75.

[0074] Example 3

[0075] The preparation method of the binary spinel ferrite provided in this example is basically the same as that in Example 2, except that the sodium hydroxide solution is added dropwise until the pH of the reaction solution is 11.

[0076] Example 4

[0077] The preparation method of the binary spinel ferrite provided in this example is basically the same as that in Example 2, except that the calcination temperature of the precursor is replaced with 600 °C.

[0078] Example 5

[0079] The preparation method of the binary spinel ferrite provided in this example is basically the same as that in Example 2, except that ethylene glycol is replaced with an equimolar amount of glycerol.

[0080] Example 6

[0081] The preparation method of the binary spinel ferrite provided in this example is basically the same as that in Example 2, except that ethylene glycol is replaced with an equimolar amount of urea.

[0082] Example 7

[0083] The preparation method of the binary spinel ferrite provided in this example is basically the same as that in Example 2, except that nickel nitrate is replaced with an equimolar amount of magnesium nitrate, and zinc nitrate is replaced with an equimolar amount of cobalt nitrate.

[0084] The binary spinel ferrite prepared in this example is magnesium-cobalt ferrite.

[0085] Example 8

[0086] The preparation method of the binary spinel ferrite provided in this example is basically the same as that in Example 2, except that nickel nitrate is replaced with cobalt nitrate in an equimolar amount.

[0087] The binary spinel ferrite prepared in this example is cobalt-zinc ferrite.

[0088] Among them, the XRD pattern of the binary spinel ferrite prepared in Example 2 is as Figure 1 shown. The XRD pattern of the binary spinel ferrite prepared in Example 3 is as Figure 2 shown. The VSM pattern of the binary spinel ferrite prepared in Example 2 is as Figure 3 shown. The VSM pattern of the binary spinel ferrite prepared in Example 3 is as Figure 4 shown. The XRD pattern of the binary spinel ferrite prepared in Example 4 is as Figure 5 shown. The XRD pattern of the binary spinel ferrite prepared in Example 5 is as Figure 6 shown. The XRD pattern of the binary spinel ferrite prepared in Example 6 is as Figure 7 shown. The XRD pattern of the binary spinel ferrite prepared in Example 7 is as Figure 8 shown. The XRD pattern of the binary spinel ferrite prepared in Example 8 is as Figure 9 shown.

[0089] Comparative Example 1

[0090] The preparation method of the binary spinel ferrite provided in this comparative example is basically the same as that in Example 2, except that ethylene glycol is replaced with an equal volume of choline chloride, that is, the preparation raw material does not contain ethylene glycol.

[0091] Comparative Example 2

[0092] The preparation method of the binary spinel ferrite provided in this comparative example is basically the same as that in Example 2, except that choline chloride is replaced with an equal volume of ethylene glycol, that is, the preparation raw material does not contain choline chloride.

[0093] Comparative Example 3

[0094] The preparation method of the binary spinel ferrite provided in this comparative example is basically the same as that in Example 2, except that the choline chloride-ethylene glycol solution is replaced with an equal volume of water, that is, the preparation raw material does not contain choline chloride and ethylene glycol.

[0095] Experimental Example

[0096] The grain size (hereinafter referred to as D), saturation magnetization (hereinafter abbreviated as Ms), and coercivity (hereinafter abbreviated as Hc) of the binary spinel ferrites prepared in each of the above examples and comparative examples were respectively detected, and the results are shown in Table 1.

[0097] Table 1 Grain size, saturation magnetization and coercivity of each binary spinel ferrite

[0098] D (nm) Ms (emu / g) Hc (Oe) Example 1 58 61 48 Example 2 75 70 53 Example 3 62 63 51 Example 4 55 55 45 Example 5 65 65 55 Example 6 57 62 52 Example 7 53 57 46 Example 8 63 64 48 Comparative Example 1 48 49 66 Comparative Example 2 51 52 70 Comparative Example 3 54 60 66

[0099] Referring to Table 1 and comparing the data of Example 2 and Comparative Examples 1-3, it can be seen that the binary spinel ferrite prepared in Example 2 has a larger grain size, a higher saturation magnetization and a lower coercivity. In Comparative Examples 1-3, since the first solvent and / or the second solvent was not added, the grain size of the spinel ferrite prepared was reduced, the saturation magnetization was decreased, or the coercivity was increased.

[0100] Although the present invention has been illustrated and described with reference to specific embodiments, it should be realized that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; those of ordinary skill in the art should understand that: without departing from the spirit and scope of the present invention, the technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such replacements and modifications within the scope of the present invention are included in the appended claims.

Claims

1. A preparation method of a binary spinel ferrite, characterized in that Comprising the following steps: Adding a precipitant solution to a mixed material containing a first solvent, a second solvent, water, iron element and other metal elements, and carrying out a reaction. After the reaction is completed, solid-liquid separation is carried out to obtain a precursor; After the precursor is calcined, the binary spinel ferrite is obtained; Wherein, the first solvent includes choline chloride; The second solvent includes at least one of glycerol and urea; In the mixed material, the molar ratio of the first solvent to the second solvent is 1-1.2:1.8-2.2; The other metal elements include two of Mg, Ni, Co and Zn elements; The molar ratio of the iron element to the other metal elements is 1.8-2.2:1; The binary spinel ferrite includes at least one of nickel-zinc ferrite, magnesium-cobalt ferrite, cobalt-zinc ferrite, magnesium-nickel ferrite, magnesium-zinc ferrite and nickel-cobalt ferrite; During the reaction, the pH value of the mixed material is 10-13; The reaction temperature is 30-80 °C; The calcination temperature is 400-700 °C.

2. The preparation method of the binary spinel ferrite according to claim 1, wherein In the mixed material, the ratio of the sum of the volumes of the first solvent and the second solvent to the volume of the water is 10-90:90-10.

3. A binary spinel ferrite, characterized in that, Prepared by using the preparation method of the binary spinel ferrite according to any one of claims 1-2; The chemical formula of the binary spinel ferrite is A x M 1-x Fe2O4, where 0 < x < 1, A and M are each independently selected from one of the elements Mg, Ni, Co, and Zn, and A and M are different elements.

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