CN107285757B - Wave-absorbing material and preparation method thereof - Google Patents
Wave-absorbing material and preparation method thereof Download PDFInfo
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Abstract
In order to overcome the problems of limited wave-absorbing bandwidth and poor wave-absorbing effect of the wave-absorbing material in the prior art, the invention provides the wave-absorbing material which is an oxide containing metal elements of Ba, Fe, Co, Mn, La, Y and Cr; in the wave-absorbing material, the mole ratio of Ba, Fe, (Co + Mn), La, Y and Cr is 15-20: 130-150: 7-15: 0.6-2: 1-4: 0.5-1.5. Meanwhile, the invention also discloses a preparation method of the wave-absorbing material. The wave-absorbing material provided by the invention has wide wave-absorbing frequency and good wave-absorbing effect.
Description
Technical Field
The invention relates to a wave-absorbing material and a preparation method thereof.
Background
With the rapid development of information technology, mobile communication, computers, household appliances and the like are rapidly popularized, and the working frequency range is wider and wider, for example, the working frequency of an induction cooker is 20-50kHz, the working frequency of a mobile phone is 800 plus 2400MHz, and the clock frequency of a computer CPU reaches more than 4 GHz. The widespread popularization of household appliances and electronic devices brings great convenience to the life of people and also brings the problem of adverse electromagnetic wave interference.
Electromagnetic interference (EMI), or electromagnetic noise, is a type of invisible pollution that cannot be felt by the sense of touch. The misoperations and even failures of electronic instruments due to electromagnetic interference (EMI) are common, and EMI resistance problems are present to a different degree in almost all information systems. The incidence of malfunction of medical electronic equipment caused by the use of mobile phones in hospitals is said to be above 66%. Electromagnetic waves radiated and leaked by electronic equipment not only cause serious interference to the electronic equipment, but also threaten the health of human beings and the safety of various military targets.
Electromagnetic radiation is one of the current pathogenic sources harmful to human health, the probability of people living in an electromagnetic wave magnetic field of more than 2 milligauss to suffer from leukemia is 2.93 times that of normal people, and the probability of suffering from muscle tumor is 326 times that of the normal people. In the case of military targets, the military targets are not only subjected to search of three-dimensional, multi-means and high-performance modern reconnaissance facilities in the air, but also threatened by reconnaissance guidance systems such as visible light, near infrared, thermal infrared and millimeter waves on the ground. Especially, the rapid development of modern radio technology and radar detection system greatly promotes the ability of searching and tracking target of war defense system. The electromagnetic radiation from military electronic devices may be a clue for enemy reconnaissance, and thus conventional camouflage (visible and infrared) has not been able to accommodate future war development. How to suppress or even eliminate EMI of electronic devices has become an important issue related to the health of people and national defense safety.
Electromagnetic interference signals reach the receiver mainly by conduction, radiation and induction. Common interference sources and frequency ranges mainly include computers (10M-100MHz), televisions, frequency modulation broadcasts, very high frequency communications (100M-1GHz), microwaves and aviation radars (1G-10 GHz). In many cases, the interfering signal is a wideband signal.
The anti-electromagnetic interference technology mainly comprises three major types of filtering, shielding and grounding, and electromagnetic shielding mainly limits the transmission of electromagnetic energy from one side space of a shielding material to the other side space. Electromagnetic waves generally decay by 3 different mechanisms as they propagate to the surface of the shielding material: firstly, the reflection on the surface of the shield is attenuated; secondly, the material absorbs and attenuates after entering the shielding body; and thirdly, multiple reflection attenuation inside the shield.
In the prior art, electromagnetic shielding is generally performed in three ways: 1. isolating electromagnetic waves by an electromagnetic shielding effect using a metal wire or a thin metal sheet, etc.; 2. carbon-based powder and other powder materials are used as coating materials to absorb electromagnetic waves; 3. ordinary ferrite is used to absorb electromagnetic waves.
However, the use of a metal wire or a thin metal sheet or the like for shielding electromagnetic waves by an electromagnetic shielding effect can protect individual shielded objects, but cannot weaken the intensity of electromagnetic radiation, and may cause interference with critical equipment. When powder materials such as carbon base and the like are used as coating materials to absorb electromagnetic waves, the absorption efficiency and the wave absorption bandwidth are limited. And the conventional ferrite has poor wave-absorbing performance.
Disclosure of Invention
The invention aims to solve the technical problems of limited wave-absorbing bandwidth and poor wave-absorbing effect of the wave-absorbing material in the prior art and provides the wave-absorbing material.
The technical scheme adopted by the invention for solving the technical problems is as follows:
providing a wave-absorbing material which is an oxide containing metal elements of Ba, Fe, Co, Mn, La, Y and Cr; in the wave-absorbing material, the mole ratio of Ba, Fe, (Co + Mn), La, Y and Cr is 15-20: 130-150: 7-15: 0.6-2: 1-4: 0.5-1.5.
Meanwhile, the invention also provides a preparation method of the wave-absorbing material, which comprises the steps of preparing a raw material mixture containing a Ba source, a Fe source, a Co source, a Mn source, a La source, a Y source and a Cr source by a molten salt method to obtain the wave-absorbing material; in the raw material mixture, the molar ratio of Ba, Fe, (Co + Mn), La, Y and Cr is 15-20: 130-150: 7-15: 0.6-2: 1-4: 0.5-1.5.
The wave-absorbing material provided by the invention is Z-type hexagonal barium ferrite, wherein the Z-type hexagonal barium ferrite is doped by taking Co and Mn with higher contents as main doping elements. Meanwhile, a small amount of La, Y and Cr is adopted for auxiliary doping. Through the matching of the main doping and the auxiliary doping, the unit cell structure and the lattice parameters in the Z-type hexagonal barium ferrite are changed, the magnetic loss is increased, the wave-absorbing capacity is improved, harmful electromagnetic waves can be effectively absorbed, and the wave-absorbing bandwidth is large.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects solved by the present invention more apparent, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The wave-absorbing material provided by the invention is an oxide containing metal elements of Ba, Fe, Co, Mn, La, Y and Cr; in the wave-absorbing material, the mole ratio of Ba, Fe, (Co + Mn), La, Y and Cr is 15-20: 130-150: 7-15: 0.6-2: 1-4: 0.5-1.5.
Specifically, the wave-absorbing material provided by the invention belongs to Z-type hexagonal barium ferrite, wherein Fe and Ba are used as main elements.
Co, Mn, La, Y and Cr with different contents exist in the wave-absorbing material as doping elements, and the wave-absorbing capacity and the wave-absorbing bandwidth of the wave-absorbing material are improved by changing the crystal cell structure and the crystal lattice parameters in the Z-type hexagonal barium ferrite.
According to the invention, Co and Mn are main doping elements. In the wave-absorbing material provided by the invention, Co is used2+Increase lattice constant, increase lattice magnetic moment and decrease centerAnd the saturation magnetization is increased at the internal temperature. Mn ions are doped into Fe2+Or Fe3+Due to Mn having a larger ionic radius than Fe2+And Fe3+The doping of Mn changes the lattice shape and parameters and thus the magnetic properties of the ferrite. According to the invention, Co and Mn are simultaneously used as main doping elements to dope the Z-type hexagonal barium ferrite, so that the wave-absorbing capacity and the wave-absorbing bandwidth of the wave-absorbing material are improved to a certain extent.
Meanwhile, La, Y and Cr are adopted as auxiliary doping elements on the premise of the main doping. La increases lattice constant, hinders domain wall motion, and reduces superexchange between tetrahedral A site and octahedral B site ions. Meanwhile, by doping Y element, the growth of Z-type hexagonal barium ferrite grains is promoted, the lattice constant is increased, the saturation magnetization is improved, the initial magnetic conductivity is increased, the coercive force is reduced, the super exchange effect between the A-site ions of the tetrahedron and the B-site ions of the octahedron is influenced, and the resistivity is increased.
In the invention, the Z-type hexagonal barium ferrite which takes Fe and Ba as main elements is subjected to the main doping and the auxiliary doping, and finally the wave-absorbing capacity and the wave-absorbing bandwidth of the wave-absorbing material are improved.
It is noted that different contents of the elements in the ferrite will result in different micro-crystalline structures and actual properties of the material as a whole. In the present invention, the main doping elements have high contents of Co and Mn, while the auxiliary doping elements have low contents of La, Y and Cr. If La, Y and Cr are too high and Co and Mn content are too low, the structure and properties of the wave-absorbing material will change, for example, M-type ferrite is formed.
According to the invention, the molar ratio of Ba, Fe, (Co + Mn), La, Y and Cr in the wave-absorbing material is 15-20: 130-150: 7-15: 0.6-2: 1-4: 0.5-1.5. Under the content composition, the wave-absorbing material has excellent wave-absorbing capacity and larger wave-absorbing bandwidth. Preferably, the molar ratio of Ba, Fe, (Co + Mn), La, Y and Cr is 17-19: 134-142: 8-12: 0.7-1: 1.5-3: 0.8-1.5.
Wherein the total molar ratio content of Co and Mn as main doping elements is 7-15. The content relationship between Co and Mn can vary within wide limits, and it is preferred that the molar ratio of the elements Co and Mn is from 0.8 to 1.2: 1.2-0.8.
Meanwhile, the wave-absorbing material provided by the invention can also contain other elements, for example, the wave-absorbing material also contains an auxiliary element R, and the auxiliary element R comprises one or more of B, Ca, Si, Sn and Mg. The content of the auxiliary element R can vary within a wide range, for example, preferably, the molar ratio of the element Ba to the auxiliary element R in the wave-absorbing material is 15-20: 0.4-2.
As mentioned above, the wave-absorbing material provided by the present invention is a Z-type hexagonal barium ferrite doped with a plurality of elements, and preferably, the wave-absorbing material comprises the following elements:
Bax1Fex2Cox3Mnx4Lax5Yx6Crx7Rx8Ox9；
wherein the element R is selected from one or more of B, Ca, Si, Sn and Mg; and, x 1: x 2: (x3+ x 4): x 5: x 6: x 7: x 8: x9 is 15-20: 130-150: 7-15: 0.6-2: 1-4: 0.5-1.5: 0-2: 238-263.
As mentioned above, preferably, x 1: x 2: (x3+ x 4): x 5: x 6: x 7: x 8: x9 is 17-19: 134-142: 8-12: 0.7-1: 1.5-3: 0.8-1.5: 1.2-1.8: 240-250.
Wherein, x 3: x4 is 0.8-1.2: 1.2-0.8.
The invention also provides a preparation method of the wave-absorbing material, and the wave-absorbing material can be prepared by a molten salt method by adopting a raw material mixture containing a Ba source, a Fe source, a Co source, a Mn source, a La source, a Y source and a Cr source. In the raw material mixture, the mol ratio of Ba, Fe, (Co + Mn), La, Y and Cr is 15-20: 130-150: 7-15: 0.6-2: 1-4: 0.5-1.5.
In the above raw material mixture, various Ba compounds commonly used in the art for preparing Z-type hexagonal barium ferrite can be used as the Ba source, and Ba sources that do not introduce other impurity elements are preferred. In the present invention, the Ba source is an oxide and/or salt of divalent Ba, for exampleIs selected from BaCO3and/BaO. BaCO is preferably used3。
Similarly, Fe source, Co source, Mn source, La source, Y source, and Cr source may be any of the compounds conventionally used for the production of magnetic materials, such as oxides. Preferably, the source of Fe is an oxide and/or salt of trivalent Fe, preferably Fe2O3. The Co source is an oxide and/or salt of divalent Co, preferably CoO. The source of Mn is an oxide and/or salt of divalent Mn, preferably MnO. The La source is trivalent La oxide and/or salt, preferably La2O3. The Y source is an oxide and/or salt of trivalent Y, preferably Y2O3. The source of Cr is an oxide and/or salt of divalent Cr, preferably CrO.
In the raw material mixture, the addition amount of the various substances is required to ensure that the molar ratio of Ba, Fe, (Co + Mn), La, Y and Cr in the raw material mixture is 15-20: 130-150: 7-15: 0.6-2: 1-4: 0.5-1.5. Wherein, in the raw material mixture, the mol ratio of the elements Co and Mn is preferably 0.8-1.2: 1.2-0.8.
After the raw material mixture is obtained, the wave-absorbing material provided by the invention can be prepared by a molten salt method. The wave-absorbing material prepared by the molten salt method has the characteristics of low cost, high purity, uniform grain size, good particle morphology and the like.
As is known in the art, the molten salt process generally employs one or more salts with low melting points as the reaction medium, and the reactants have a solubility in the molten salt such that the reaction proceeds at the atomic level. After the reaction is finished, the salt is dissolved by adopting a proper solvent, and a synthetic product can be obtained after filtration and washing. Because the low-melting-point salt is used as a reaction medium, a liquid phase appears in the synthesis process, and reactants have certain solubility in the liquid phase, the diffusion rate of ions is greatly accelerated, so that the reactants are mixed in the liquid phase at an atomic scale, and the reaction is converted from a solid-solid reaction into a solid-liquid reaction. Compared with the conventional solid phase method, the method has the advantages of simple process, low synthesis temperature, short heat preservation time, uniform chemical components of the synthesized powder, good crystal morphology, high phase purity and the like. In addition, the salt is easy to separate and can be reused.
In the invention, preferably, the method for preparing the wave-absorbing material comprises the following steps:
s1, mixing the raw material mixture with medium salt, and performing ball milling and drying to obtain a material to be fired;
s2, sintering the material to be sintered to obtain a sintered material; the conditions of the sintering treatment are as follows: the heating speed is 2-8 ℃/min, the sintering temperature is 1000-;
and S3, performing ball milling on the sintered material, and then filtering, cleaning and drying to obtain the wave-absorbing material.
As mentioned above, in the preparation of the product by the molten salt method, a salt is provided as a reaction medium. In the present invention, in step S1, the raw material mixture is mixed with a medium salt.
In the present invention, the above-mentioned medium salt can be used as a salt used in a conventional molten salt method, and for example, the medium salt is NaCl and KCl. The weight ratio of NaCl to KCl in the medium salt may vary within wide limits and may, for example, be from 1 to 100: 100-1, preferably 40-50: 60-50, for example NaCl: KCl is 43.94: 56.06.
in step S1, the relative content of the medium salt and the raw material mixture may vary within a wide range, for example, the weight ratio of the total weight of the medium salt to the raw material mixture is 0.4-1.6: 1.6-0.4. Specifically, the ratio of 1: 1.
after mixing the raw material mixture with the medium salt, ball milling is preferably performed. The ball milling method and the ball milling equipment can adopt the conventional method, for example, ball milling is carried out for 4-8h at the rotating speed of 200-400 r/min in the presence of a solvent. The solvent used in the ball milling may be any of the conventional solvents, and for example, one or more of ethanol, diethylene glycol, xylene, and acetone may be used. Ethanol is preferably used.
And after ball milling, drying the material to obtain the material to be fired. The specific drying method can be conventional, and can be dried for 12-24h in a drying oven, for example.
According to the invention, in step S2, the material to be sintered is further sintered to obtain a sintered material. In the invention, the specific conditions of the sintering treatment are as follows: the heating rate is 2-8 ℃/min, the sintering temperature is 1000-1350 ℃, and the sintering time is 2-8 h.
After sintering, cooling the sintered material, and then performing ball milling again. At this time, the ball milling method is similar to that in step S1, and ball milling is carried out for 2-6h at the rotation speed of 200-400 r/min in the presence of the solvent. Likewise, the solvent can adopt one or more of ethanol, diethylene glycol, xylene and acetone. Ethanol is preferably used.
And finally, filtering, cleaning and drying the ball-milled materials to obtain the wave-absorbing material.
The medium salt is contained in the material, so that the medium salt is required to be cleaned and removed. In the invention, the ball-milled material can be cleaned by deionized water until no Cl exists-Until now, AgNo can be used3The solution was checked for absence of white precipitate. And finally drying in a drying oven for 12-24 h.
According to the present invention, it is preferable that the raw material mixture further contains an auxiliary agent, wherein the auxiliary agent is a compound of an auxiliary agent element R, and the auxiliary agent element R includes one or more of B, Ca, Si, Sn, and Mg. Preferably, the auxiliary is selected from B2O3、CaO、SiO2、SnO2、MgO、V2O5、SnO2、Nb2O5One or more of (a).
The addition of the auxiliary agent in the raw material mixture can reduce the sintering temperature, so that the wave-absorbing material can form liquid phase sintering at a lower temperature, thereby reducing the energy consumption. Meanwhile, the relative density of the wave-absorbing material can be improved by sintering in the presence of the auxiliary agent, and the strength of the wave-absorbing material is improved.
According to the invention, the content of the auxiliary agent added to the raw material mixture can vary within a wide range, and preferably, the molar ratio of the Ba source to the auxiliary agent in the raw material mixture is 15 to 20: 0.4-2.
The wave-absorbing material prepared by the method has excellent wave-absorbing performance and larger wave-absorbing bandwidth.
The present invention will be further illustrated by the following examples.
Examples 1 to 7
This example is used to illustrate the wave-absorbing material and the preparation method thereof disclosed in the present invention.
1. Weighing the materials according to the table 1, wherein the auxiliary agents are B2O3, CaO, SiO2, SnO2 and MgO, and obtaining a raw material mixture.
TABLE 1
2. Weighing NaCl and KCl according to the mass ratio of 1:1 of the total mass of the NaCl and the KCl to the total mass of the raw material mixture, wherein the mass ratio of the NaCl to the KCl is 43.94: 56.06.
3. putting the materials into a ball milling tank, adding ethanol until the materials just overflow, and carrying out ball milling for 6 hours at the rotating speed of 300 r/min.
4. And taking out the ball-milled materials, and placing the materials in a drying box for drying for 18h to obtain the materials to be fired.
5. And placing the material to be sintered in a sintering furnace for sintering treatment to obtain the sintered material. The sintering treatment conditions are as follows: the sintering time is 6h, and the sintering temperature is 1200 ℃; the temperature rise speed is 5 ℃/min.
6. And after sintering, putting the sintered material into a ball milling tank, adding 400g of ethanol, carrying out ball milling for 4 hours at the rotating speed of 300 r/min, and then filtering.
7. Washing the ball-milled materials with deionized water until no Cl is generated-Until now, AgNo3The solution was checked for absence of white precipitate.
8. And (5) drying the cleaned material in a drying oven for 18h to obtain the wave-absorbing material.
Example 8
This example is used to illustrate the wave-absorbing material and the preparation method thereof disclosed in the present invention.
1. The materials were weighed out as in Table 1 to obtain a raw material mixture.
2. Weighing NaCl and KCl according to the mass ratio of 1:1 of the total mass of the NaCl and the KCl to the total mass of the raw material mixture, wherein the mass ratio of the NaCl to the KCl is 43.94: 56.06.
3. putting the materials into a ball milling tank, adding ethanol until the ethanol just overflows the materials, and carrying out ball milling for 8 hours at the rotating speed of 200 revolutions per minute.
4. And taking out the ball-milled materials, and placing the materials in a drying box for drying for 12 hours to obtain the materials to be fired.
5. And placing the material to be sintered in a sintering furnace for sintering treatment to obtain the sintered material. The sintering treatment conditions are as follows: the sintering time is 3h, and the sintering temperature is 1300 ℃; the temperature rise speed is 8 ℃/min.
6. And after sintering, putting the sintered material into a ball milling tank, adding 400g of ethanol, carrying out ball milling for 6 hours at the rotating speed of 200 revolutions per minute, and then filtering.
7. Washing the ball-milled materials with deionized water until no Cl is generated-Until now, AgNo3The solution was checked for absence of white precipitate.
8. And (5) drying the cleaned material in a drying oven for 12 hours to obtain the wave-absorbing material.
Example 9
This example is used to illustrate the wave-absorbing material and the preparation method thereof disclosed in the present invention.
1. The materials were weighed out as in Table 1 to obtain a raw material mixture.
2. Weighing NaCl and KCl according to the mass ratio of 1:1 of the total mass of the NaCl and the KCl to the total mass of the raw material mixture, wherein the mass ratio of the NaCl to the KCl is 43.94: 56.06.
3. putting the materials into a ball milling tank, adding ethanol until the ethanol just overflows the materials, and carrying out ball milling for 4 hours at the rotating speed of 400 r/min.
4. And taking out the ball-milled materials, and placing the materials in a drying box for drying for 24 hours to obtain the materials to be fired.
5. And placing the material to be sintered in a sintering furnace for sintering treatment to obtain the sintered material. The sintering treatment conditions are as follows: the sintering time is 8h, and the sintering temperature is 1000 ℃; the temperature rise speed is 3 ℃/min.
6. And after sintering, putting the sintered material into a ball milling tank, adding 400g of ethanol, carrying out ball milling for 2h at the rotating speed of 400 r/min, and then filtering.
7、Washing the ball-milled materials with deionized water until no Cl is generated-Until now, AgNo3The solution was checked for absence of white precipitate.
8. And (5) drying the cleaned material in a drying oven for 24 hours to obtain the wave-absorbing material.
Comparative examples 1 to 8
The comparative example is used for comparing and explaining the wave-absorbing material and the preparation method thereof disclosed by the invention.
A wave-absorbing material was prepared according to the method of example 1, except that the composition of the raw material mixture was as shown in table 2.
TABLE 2
Performance testing
The wave-absorbing materials prepared in the above examples 1 to 9 and comparative examples 1 to 8 were subjected to dynamic electromagnetic parameter testing. The test method is as follows:
preparation of coaxial ring samples: wave-absorbing materials with different numbers are respectively mixed with paraffin according to a certain proportion, heated, melted and uniformly stirred, and pressed into annular samples with the inner diameter of 3mm, the outer diameter of 7mm and the thickness of 2.8-3.8mm after being cooled.
And (3) placing the coaxial ring sample in a test coaxial pipe sleeve, and then measuring the wave absorption of the 1M-10GHz frequency band by using an HP8720ET analyzer.
The test results obtained are filled in Table 3.
TABLE 3
| Numbering | 1M | 10M | 20M | 300M | 1G | 5G | 10G |
| Example 1 | 8 | 8 | 10 | 12 | 14 | 19 | 17 |
| Example 2 | 7 | 8 | 9 | 11 | 14 | 18 | 16 |
| Example 3 | 7 | 8 | 9 | 11 | 14 | 18 | 15 |
| Example 4 | 7 | 8 | 10 | 12 | 13 | 19 | 16 |
| Example 5 | 7 | 8 | 9 | 11 | 13 | 18 | 15 |
| Example 6 | 7 | 8 | 9 | 11 | 14 | 18 | 16 |
| Example 7 | 7 | 8 | 9 | 11 | 13 | 18 | 15 |
| Example 8 | 7 | 8 | 9 | 11 | 14 | 19 | 16 |
| Example 9 | 8 | 9 | 10 | 12 | 15 | 20 | 18 |
| Comparative example 1 | 5 | 5 | 7 | 8 | 10 | 15 | 13 |
| Comparative example 2 | 5 | 5 | 6 | 7 | 9 | 15 | 14 |
| Comparative example 3 | 3 | 3 | 5 | 5 | 9 | 11 | 10 |
| Comparative example 4 | 2 | 2 | 3 | 4 | 6 | 9 | 7 |
| Comparative example 5 | 4 | 4 | 6 | 8 | 9 | 11 | 9 |
| Comparative example 6 | 2 | 2 | 3 | 4 | 5 | 9 | 6 |
| Comparative example 7 | 2 | 2 | 2 | 3 | 4 | 8 | 6 |
| Comparative example 8 | 4 | 4 | 5 | 6 | 7 | 11 | 8 |
From the test results in table 1, it can be seen that the wave-absorbing material provided by the invention has excellent wave-absorbing performance and larger wave-absorbing bandwidth.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (8)
1. The wave-absorbing material is characterized in that the wave-absorbing material is an oxide containing metal elements of Ba, Fe, Co, Mn, La, Y and Cr;
in the wave-absorbing material, the mole ratio of Ba, Fe, (Co + Mn), La, Y and Cr is 15-20: 130-150: 7-15: 0.6-2: 1-4: 0.5-1.5;
in the wave-absorbing material, the molar ratio of elements Co to Mn is 0.8-1.2: 1.2-0.8;
the wave-absorbing material also contains an auxiliary agent element R, wherein the auxiliary agent element R comprises one or more of B, Ca, Si, Sn and Mg;
the molar ratio of the element Ba to the auxiliary element R is 15-20: 0.4-2.
2. The wave-absorbing material according to claim 1, wherein the wave-absorbing material comprises the following elements:
Bax1Fex2Cox3Mnx4Lax5Yx6Crx7Rx8Ox9；
wherein the element R is selected from one or more of B, Ca, Si, Sn and Mg;
and, x 1: x 2: (x3+ x 4): x 5: x 6: x 7: x 8: x9 is 15-20: 130-150: 7-15: 0.6-2: 1-4: 0.5-1.5: 0.4-2: 238-263.
3. The method for preparing the wave-absorbing material according to claim 1 or 2, wherein a raw material mixture containing a Ba source, a Fe source, a Co source, a Mn source, a La source, a Y source and a Cr source is adopted, the raw material mixture further contains an auxiliary agent, the auxiliary agent is a compound of an auxiliary agent element R, and the auxiliary agent element R comprises one or more of B, Ca, Si, Sn and Mg; preparing the wave-absorbing material by a molten salt method to obtain the wave-absorbing material;
in the raw material mixture, the molar ratio of Ba, Fe, (Co + Mn), La, Y and Cr is 15-20: 130-150: 7-15: 0.6-2: 1-4: 0.5-1.5;
in the wave-absorbing material, the molar ratio of elements Co to Mn is 0.8-1.2: 1.2-0.8;
in the wave-absorbing material, the molar ratio of element Ba to auxiliary agent element R is 15-20: 0.4-2.
4. The method of claim 3, comprising the steps of:
s1, mixing the raw material mixture with medium salt, and performing ball milling and drying to obtain a material to be fired;
s2, sintering the material to be sintered to obtain a sintered material; the conditions of the sintering treatment are as follows: the heating speed is 2-8 ℃/min, the sintering temperature is 1000-;
and S3, performing ball milling on the sintered material, and then filtering, cleaning and drying to obtain the wave-absorbing material.
5. The method according to claim 4, wherein in step S1, the medium salts are NaCl and KCl;
the weight ratio of NaCl to KCl in the medium salt is 40-50: 60-50 parts of;
the weight ratio of the total weight of the medium salt to the raw material mixture is 0.4-1.6: 1.6-0.4.
6. The preparation method according to claim 4, wherein in the step S1, the ball milling method comprises: adding a solvent, and ball-milling at the rotation speed of 200-400 r/min for 4-8 h;
in step S3, the ball milling method includes: adding a solvent, and ball-milling at the rotation speed of 200-;
the solvents in the steps S1 and S3 are respectively and independently selected from one or more of ethanol, diethylene glycol, xylene and acetone.
7. The production method according to claim 3, wherein the Ba source is an oxide and/or a salt of divalent Ba;
the Fe source is selected from the oxides and/or salts of trivalent Fe;
the Co source is selected from divalent Co oxides and/or salts;
the source of Mn is selected from oxides and/or salts of divalent Mn;
the La source is selected from oxides and/or salts of trivalent La;
the Y source is selected from oxides and/or salts of trivalent Y;
the source of Cr is selected from the group consisting of oxides and/or salts of divalent Cr.
8. The method according to claim 3, wherein the auxiliary is selected from B2O3、CaO、SiO2、SnO2And MgO.
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| CN102260072A (en) * | 2011-06-13 | 2011-11-30 | 中国地质大学（武汉） | Method for synthesizing high-performance barium ferrite by using molten salt as flux and reaction medium |
| CN103086707A (en) * | 2013-01-16 | 2013-05-08 | 陕西科技大学 | Preparation method for Ni-Mn-Co multi-doped barium ferrite wave-absorbing material |
| CN103086706A (en) * | 2013-01-16 | 2013-05-08 | 陕西科技大学 | Preparation method for Zr-Mn-Co multi-doped barium ferrite wave-absorbing material |
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| CN103086707A (en) * | 2013-01-16 | 2013-05-08 | 陕西科技大学 | Preparation method for Ni-Mn-Co multi-doped barium ferrite wave-absorbing material |
| CN103086706A (en) * | 2013-01-16 | 2013-05-08 | 陕西科技大学 | Preparation method for Zr-Mn-Co multi-doped barium ferrite wave-absorbing material |
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