CN115784317A - LaCaFeO wave-absorbing material and preparation method thereof - Google Patents
LaCaFeO wave-absorbing material and preparation method thereof Download PDFInfo
- Publication number
- CN115784317A CN115784317A CN202211529019.6A CN202211529019A CN115784317A CN 115784317 A CN115784317 A CN 115784317A CN 202211529019 A CN202211529019 A CN 202211529019A CN 115784317 A CN115784317 A CN 115784317A
- Authority
- CN
- China
- Prior art keywords
- wave
- absorbing material
- lacafeo
- preparation
- absorbing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000011358 absorbing material Substances 0.000 title claims abstract description 79
- 238000002360 preparation method Methods 0.000 title claims abstract description 26
- 238000006243 chemical reaction Methods 0.000 claims abstract description 13
- 238000000034 method Methods 0.000 claims abstract description 10
- 238000005245 sintering Methods 0.000 claims abstract description 6
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 93
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 43
- 239000011575 calcium Substances 0.000 claims description 33
- 238000001354 calcination Methods 0.000 claims description 15
- 238000001879 gelation Methods 0.000 claims description 11
- 238000003756 stirring Methods 0.000 claims description 11
- 238000001035 drying Methods 0.000 claims description 8
- 229910052742 iron Inorganic materials 0.000 claims description 8
- 229910021645 metal ion Inorganic materials 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 6
- 229910052746 lanthanum Inorganic materials 0.000 claims description 5
- 229910001960 metal nitrate Inorganic materials 0.000 claims description 5
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims 1
- 229910052791 calcium Inorganic materials 0.000 claims 1
- 238000010438 heat treatment Methods 0.000 claims 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 claims 1
- 239000000463 material Substances 0.000 abstract description 34
- 238000010521 absorption reaction Methods 0.000 abstract description 28
- 230000008569 process Effects 0.000 abstract description 5
- 230000003647 oxidation Effects 0.000 abstract description 3
- 238000007254 oxidation reaction Methods 0.000 abstract description 3
- 230000015572 biosynthetic process Effects 0.000 abstract 1
- 238000003837 high-temperature calcination Methods 0.000 abstract 1
- 238000009776 industrial production Methods 0.000 abstract 1
- 238000003786 synthesis reaction Methods 0.000 abstract 1
- 238000002310 reflectometry Methods 0.000 description 20
- ZCCIPPOKBCJFDN-UHFFFAOYSA-N calcium nitrate Chemical compound [Ca+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ZCCIPPOKBCJFDN-UHFFFAOYSA-N 0.000 description 12
- VCJMYUPGQJHHFU-UHFFFAOYSA-N iron(3+);trinitrate Chemical compound [Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VCJMYUPGQJHHFU-UHFFFAOYSA-N 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- 239000002131 composite material Substances 0.000 description 9
- 230000010287 polarization Effects 0.000 description 8
- 229910001424 calcium ion Inorganic materials 0.000 description 7
- -1 iron ions Chemical class 0.000 description 7
- FYDKNKUEBJQCCN-UHFFFAOYSA-N lanthanum(3+);trinitrate Chemical compound [La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FYDKNKUEBJQCCN-UHFFFAOYSA-N 0.000 description 7
- 239000013078 crystal Substances 0.000 description 6
- 239000000843 powder Substances 0.000 description 5
- 239000002356 single layer Substances 0.000 description 5
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 description 4
- 238000007605 air drying Methods 0.000 description 4
- 239000008367 deionised water Substances 0.000 description 4
- 229910021641 deionized water Inorganic materials 0.000 description 4
- 238000005303 weighing Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000002441 X-ray diffraction Methods 0.000 description 2
- 230000002745 absorbent Effects 0.000 description 2
- 239000002250 absorbent Substances 0.000 description 2
- 239000006096 absorbing agent Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 230000005670 electromagnetic radiation Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000011031 large-scale manufacturing process Methods 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- QXPQVUQBEBHHQP-UHFFFAOYSA-N 5,6,7,8-tetrahydro-[1]benzothiolo[2,3-d]pyrimidin-4-amine Chemical compound C1CCCC2=C1SC1=C2C(N)=NC=N1 QXPQVUQBEBHHQP-UHFFFAOYSA-N 0.000 description 1
- AFCARXCZXQIEQB-UHFFFAOYSA-N N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CCNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 AFCARXCZXQIEQB-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 239000002262 Schiff base Substances 0.000 description 1
- 150000004753 Schiff bases Chemical class 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000000536 complexating effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229920001940 conductive polymer Polymers 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000005307 ferromagnetism Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- MVFCKEFYUDZOCX-UHFFFAOYSA-N iron(2+);dinitrate Chemical compound [Fe+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MVFCKEFYUDZOCX-UHFFFAOYSA-N 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N nitrate group Chemical group [N+](=O)([O-])[O-] NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 239000012188 paraffin wax Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Landscapes
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
Abstract
The invention provides a LaCaFeO wave-absorbing material and a preparation method thereof, relating to the technical field of microwave absorbing materials. The molecular formula of the LaCaFeO wave-absorbing material is La x Ca y Fe 2 O 5 Wherein x is more than 0 and less than or equal to 0.3, y is more than or equal to 1.7 and less than or equal to 2, the wave-absorbing material of the component can absorb electromagnetic waves in a 2-18GHz microwave band, the effective absorption frequency band is wide, the absorption efficiency is high (more than 90 percent), and the wave-absorbing material has excellent thermal stability and oxidation resistance; the material of the invention is lower than other wave-absorbing materials in the market, and meanwhile, the invention provides the preparation method of the LaCaFeO wave-absorbing material, the wave-absorbing material can be obtained through sol-gel reaction, pre-sintering and high-temperature calcination, the synthesis process is simple, and the invention is suitable for large-scale industrial production.
Description
Technical Field
The invention relates to the technical field of microwave absorbing materials, in particular to a LaCaFeO wave absorbing material and a preparation method thereof.
Background
With the development of modern science and technology, various electronic and electrical equipment provide high efficiency for social production and bring great convenience for daily life of people. Meanwhile, the electromagnetic radiation and interference generated in the working process of electronic and electrical equipment can influence the production and life of people, so that the electromagnetic environment of human living space is increasingly worsened. In addition, the wide application of electromagnetic waves in science and technology also brings new social problems, becomes a new pollution source which has great harmfulness and is not easy to protect after water sources, atmosphere and noise, not only influences normal communication, but also directly harms human health, and becomes a hot problem concerned by the society and the scientific community. Furthermore, electromagnetic radiation can also have a detrimental effect on electronic devices. High-frequency equipment, especially high-power high-frequency equipment, has large output energy during working, and the formed high-frequency radiation is very strong, so that the high-frequency equipment can generate serious interference on other surrounding electronic equipment, instruments and meters, communication signals and the like, and even can not normally work, thereby causing serious consequences.
In order to solve the above problems, research on wave-absorbing materials capable of absorbing electromagnetic waves is a primary task for researchers. At present, the novel wave-absorbing material needs to meet the characteristics of thinness, lightness, width, strength and the like, and the future wave-absorbing material needs to meet higher requirements of multi-spectrum stealth, environmental adaptation, high temperature resistance, ocean climate resistance, nuclear radiation resistance, impact resistance and the like. The existing novel wave absorbing agent comprises various new materials such as nano, chiral and conductive polymers, polycrystalline iron fiber absorbing materials, schiff base type absorbing agents, plasma stealth materials, high-temperature-resistant ceramic wave absorbing materials, multifunctional wave absorbing materials, multi-band wave absorbing materials, intelligent wave absorbing materials and the like.
An oxide generally refers to a composite compound of an iron group and one or more other suitable metal elements, and is a semiconductor in terms of its conductivity, but is used as a magnetic medium in applications. The oxide is a double-complex dielectric material which absorbs electromagnetic wavesAnd, in terms of dielectric properties, from polarization effects; in the microwave band, the magnetic property is mainly determined by natural resonance, which is the main mechanism of oxide absorption of electromagnetic waves. Oxide with its higher mu r The value and the low preparation cost are the most commonly used microwave absorbent, and the advantages of high absorption efficiency, thin coating and wide frequency band are the advantages of the oxide absorbent. In addition, oxides at low frequencies (f)<1 GHz) with a higher μ r Value of epsilon r The composite material is small, so that the composite material has obvious advantages as a matching material and has good application prospect.
However, the absorption band of the existing oxide wave-absorbing material is narrow, and the absorption efficiency needs to be improved.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a LaCaFeO wave-absorbing material and a preparation method thereof.
In order to achieve the above purpose, the technical scheme of the invention is realized by the following technical scheme:
a LaCaFeO wave-absorbing material with a molecular formula of La x Ca y Fe 2 O 5 Wherein x is more than 0 and less than or equal to 0.3, and y is more than or equal to 1.7 and less than 2.
The La x Ca y Fe 2 O 5 The molecular formula of the wave-absorbing material is preferably La (0.1～0.3) Ca (1.7～1.9) Fe 2 O 5 More preferably La (0.15～0.25) Ca (0.75～0.85) Fe 2 O 5 Most preferably La 0.2 Ca 1.8 Fe 2 O 5 。
A preparation method of a LaCaFeO wave-absorbing material comprises the following steps:
(1) Mixing metal nitrates of La, ca and Fe with a citric acid solution, and stirring for a gelation reaction to obtain a gel;
(2) Pre-burning and calcining the gel in sequence to obtain a LaCaFeO wave-absorbing material;
preferably, the citric acid solution is obtained by mixing citric acid and deionized water, and the mass concentration of the citric acid solution is preferably 36.23% -50.71%, more preferably 40.1-46.5%, and most preferably 44.4%.
Preferably, the molar ratio of the total molar amount of metal ions in the metal nitrate to the citric acid in the citric acid solution is 1: 1.2.
The temperature of the gelation reaction is preferably 85 ℃, and the time is preferably 3-6h, and more preferably 4h; the gelation reaction is preferably carried out under the condition of stirring, the rotating speed of the stirring is preferably 260-360r/min, more preferably 280-340r/min, and most preferably 320r/min, and during the gelation reaction, the metal nitrate forms black-red viscous gel through hydrogen bonds under the complexing action of citric acid to obtain the gel.
Preferably, the gel is dried before pre-burning, the drying temperature is preferably 90-130 ℃, more preferably 100-120 ℃, most preferably 110 ℃, and the drying time is preferably 12-24h, more preferably 16-22 h, most preferably 20h.
Preferably, the temperature of the pre-burning in the step (2) is 400 ℃, and the pre-burning time is 1h.
Preferably, the calcining temperature in the step (2) is 800 ℃, and the calcining time is 20h.
The invention provides a LaCaFeO wave-absorbing material and a preparation method thereof, compared with the prior art, the LaCaFeO wave-absorbing material has the advantages that:
(1) The invention utilizes La 3+ Alkaline earth element Ca replacing A site 2+ La ions and Ca ions have similar radiuses (the radius of the Ca ions is slightly smaller than that of the La ions), so that lattice distortion is small, the material with small lattice distortion degree has strong magnetism, and the doping is carried out on the Ca ions 2 Fe 2 O 5 The material has great influence, can reduce the degree of lattice distortion, enables the material to have ferromagnetism, changes the dielectric property of the magnetic wave-absorbing material, adjusts the complex dielectric constant of the material, enables the material to have better impedance matching, finally leads the reflection of the wave-absorbing material to microwaves to be reduced, and further improves the wave-absorbing performance of the magnetic wave-absorbing material; and La element is doped, so that magnetocrystalline anisotropy field and diffusion activation energy of the magnetic wave-absorbing material can be obviously changed, and the common resonance absorption peak and domain wall of the magnetic wave-absorbing material are increasedAnd the absorption peak of the wave-absorbing material has a wider wave-absorbing frequency band while vibrating the absorption peak. The polarization of the dielectric medium comprises electron displacement polarization, ion displacement polarization, interface polarization, space charge polarization, etc., the change of complex dielectric constant is mainly related to inherent dipole moment orientation polarization and crystal interface polarization, and La 3+ Alkaline earth element Ca replacing A site 2+ Can reduce oxygen vacancy in the system, reduce conductivity, reduce complex dielectric constant, improve impedance matching, change the wave-absorbing performance of the material, ensure that the obtained wave-absorbing material can absorb electromagnetic waves in a 2-18GHz microwave band and has wide absorption frequency band (the existing oxide absorbs the electromagnetic waves in the R band of the oxide)<Bandwidth of-10 dB is typical>2 GHz), high absorption efficiency (more than 90%), and good thermal stability and oxidation resistance of the wave-absorbing material.
(2) In the present invention, when the calcination temperature is raised to 800 ℃, la is added (0～0.3) Ca (1.7～2) Fe 2 O 5 The powder can obtain a relatively pure perovskite structure, and the increase of the calcination temperature can promote the growth of crystal grains and reduce the resistivity of the crystal grains.
(3) The invention provides a preparation method of the LaCaFeO wave-absorbing material, the wave-absorbing material can be obtained through sol-gel reaction, pre-sintering and calcining, the production cost is low, the preparation process is simple, and the preparation method is suitable for large-scale production.
Description of the drawings:
FIG. 1 is XRD spectra of the oxide composite materials prepared in examples 1 to 3 and the oxide composite material prepared in comparative example 1;
FIG. 2 is a reflection rate loss graph of the LaCaFeO wave-absorbing materials prepared in examples 1-3 and comparative example 1 of the invention when the thickness is 2.4 mm;
FIG. 3 shows Ca prepared in comparative example 1 of the present invention 2 Fe 2 O 5 A reflectivity loss graph of the wave-absorbing material;
FIG. 4 shows La prepared in example 1 of the present invention 0.1 Ca 1.9 Fe 2 O 5 A reflectivity loss graph of the wave-absorbing material;
FIG. 5 shows La prepared in example 2 of the present invention 0.2 Ca 1.8 Fe 2 O 5 A reflectivity loss graph of the wave-absorbing material;
FIG. 6 shows La prepared according to example 3 of the present invention 0.3 Ca 1.7 Fe 2 O 5 And (3) a reflectivity loss graph of the wave-absorbing material.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.
Example 1:
preparation of La 0.1 Ca 1.9 Fe 2 O 5 Wave-absorbing material:
(1) According to the formula La 0.1 Ca 1.9 Fe 2 O 5 Weighing 4.78g of calcium nitrate with the purity of more than or equal to 99.9%, 8.61g of ferric nitrate and 0.46g of lanthanum nitrate, weighing 10.74g of citric acid according to the molar ratio of metal ions (calcium ions, iron ions and lanthanum ions) to citric acid of 1: 1.2, mixing the citric acid with deionized water to obtain a citric acid solution, adding the calcium nitrate, the ferric nitrate and the lanthanum nitrate into the citric acid solution, putting the obtained solution into a water bath, continuously stirring at constant temperature and under the condition of 80 ℃ by magnetic force (the stirring speed is 280 r/min), and carrying out gelation reaction for 4 hours to obtain gel;
(2) Putting the gel into a forced air drying oven for drying at 110 ℃, pre-burning the obtained dried material for 1h at 400 ℃, putting the obtained material into a muffle furnace for calcining for 10h at 800 ℃ to obtain an oxide wave-absorbing material, and marking the oxide wave-absorbing material as La 0.1 Ca 1.9 Fe 2 O 5 。
Example 2:
preparation of La 0.2 Ca 1.8 Fe 2 O 5 Wave-absorbing material
(1) According to the formula La 0.2 Ca 1.8 Fe 2 O 5 4.37g of calcium nitrate and nitric acid with the purity of more than or equal to 99.9 percent are weighed8.31g of iron and 0.89g of lanthanum nitrate, weighing 10.38g of citric acid according to the molar ratio of metal ions (calcium ions, iron ions and lanthanum ions) to citric acid of 1: 1.2, mixing citric acid with deionized water to obtain a citric acid solution, adding calcium nitrate, iron nitrate and lanthanum nitrate into the citric acid solution, putting the obtained solution into a water bath, continuously stirring by magnetic force at constant temperature of 90 ℃ (the stirring speed is 300 r/min), and carrying out gelation reaction for 3 hours to obtain gel;
(2) Putting the gel into a forced air drying oven for drying at 100 ℃, pre-burning the obtained dried substance for 2h at 400 ℃, putting the obtained material into a muffle furnace for calcining for 15h at 600 ℃ to obtain an oxide wave-absorbing material, and marking the oxide wave-absorbing material as La 0.2 Ca 1.8 Fe 2 O 5 。
Example 3:
preparation of La 0.3 Ca 1.7 Fe 2 O 5 Wave-absorbing material:
(1) According to the formula La 0.3 Ca 1.7 Fe 2 O 5 3.99g of calcium nitrate with the purity of more than or equal to 99.9 percent, 8.04g of ferric nitrate and 1.29g of lanthanum nitrate are weighed, 10.04g of citric acid is weighed according to the molar ratio of metal ions (calcium ions, iron ions and lanthanum ions) to the citric acid of 1: 1.2, the citric acid and deionized water are mixed to obtain a citric acid solution, then the lanthanum nitrate, dysprosium nitrate and the ferric nitrate are added into the citric acid solution, the obtained solution is placed into a water bath, and is continuously stirred by constant temperature magnetic force at the temperature of 95 ℃ (the stirring speed is 320 r/min) for gelation reaction for 3.2 hours to obtain gel;
(2) Putting the gel into a forced air drying oven for drying at 90 ℃, pre-burning the obtained dried material for 2h at 600 ℃, putting the obtained material into a muffle furnace for calcining for 10h at 900 ℃ to obtain an oxide wave-absorbing material, and marking the oxide wave-absorbing material as La 0.3 Ca 1.7 Fe 2 O 5 。
Comparative example 1:
Ca 2 Fe 2 O 5 preparing a wave-absorbing material:
(1) According to the formula Ca 2 Fe 2 O 5 Weighing the mixture with the purity of more than or equal to 99.9 percent8.92g of ferric nitrate and 5.21g of calcium nitrate, then 13.91g of citric acid is weighed according to the molar ratio of metal ions (iron ions and calcium ions) to citric acid of 1: 1.2, citric acid and distilled water are mixed to obtain a citric acid solution, lanthanum nitrate and ferric nitrate are added into the citric acid solution, the obtained solution is put into a water bath kettle, and the mixture is continuously stirred by constant temperature magnetic force at the temperature of 85 ℃ (the stirring speed is 260 r/min) for gelation reaction for 3 hours to obtain gel;
(2) Putting the gel into a forced air drying oven for drying at 110 ℃, pre-burning the obtained dried substance for 1h at 400 ℃, putting the obtained material into a muffle furnace for calcining for 20h at 800 ℃ to obtain a wave-absorbing material, and recording Ca 2 Fe 2 O 5 。
Test example
1. XRD detection was performed on the oxide composite materials prepared in examples 1 to 3 and the oxide composite material prepared in comparative example 1 to obtain XRD patterns, as shown in fig. 1.
As can be seen from the diffraction crystal planes corresponding to the different diffraction peaks in FIG. 1, the oxide composite materials prepared in examples 1 to 3 and the oxide composite material prepared in comparative example 1 were made of Ca 2 Fe 2 O 5 Single-phase composition, which proves that the La element successfully replaces the Ca element in the crystal, and the crystal structure is stable without generating a second phase.
2. The reflectivity of the oxide wave-absorbing materials prepared in examples 1 to 3 and comparative example 1 was measured:
the measuring method comprises the following steps: mixing powder (oxide wave-absorbing material) and paraffin = 3: 1 (mass ratio), preparing coaxial samples with the outer diameter and the inner diameter of 7mm and 3mm respectively and the thickness of 2.5-3.5 mm, measuring the complex permeability and the complex dielectric constant of the sample at the frequency band of 2-18GHz respectively by adopting an HP8755ES microwave vector network analyzer, and then calculating and simulating the reflectivity R of the single-layer wave-absorbing material by adopting the following formula:
in the formula, epsilon r 、μ r And d is divided intoThe relative dielectric constant, the relative permeability and the thickness of the wave-absorbing material are respectively, f is the frequency of the electromagnetic wave, c is the propagation speed (namely the light speed) of the electromagnetic wave in a free space, and j is an imaginary number unit.
When the reflectivity of the oxide wave-absorbing materials prepared in examples 1 to 3 and comparative example 1 is tested:
A. for Ca prepared in comparative example 1 2 Fe 2 O 5 The calculated reflectivities R of the simulated single-layer wave-absorbing material with the thicknesses of 2.2mm, 2.6mm, 3.0mm, 3.4mm and 3.8mm are shown in fig. 3:
from the figure, it can be seen that: the minimum reflectance peak is about-12.07 dB (absorption about 93.79%) at 14.4GHz when the material thickness is 2.2mm, about-17.25 dB (absorption about 98.13%) at 14.16GHz when the material thickness is 2.6mm, about-10.91B (absorption about 91.89%) at 13.6GHz when the material thickness is 3.0mm, about-7.41 dB (absorption about 81.84%) at 13.36 when the material thickness is 3.4mm, and about-5.8 dB (absorption about 73.7%) at 14.16 when the material thickness is 3.8 mm. Thus, ca 2 Fe 2 O 5 Has certain wave-absorbing performance.
B. For La prepared in example 1 0.1 Ca 1.9 Fe 2 O 5 The reflectivities R of the simulated single-layer wave-absorbing material with the thicknesses of 2.0mm,2.4mm,2.8mm,3.2mm and 3.6mm are calculated, and the result is shown in FIG. 4:
from the figure, it can be seen that: in all the thicknesses, the minimum reflectivity peak value is less than-10 dB (the absorptivity is more than 90%), the bandwidth of R < -10dB is wide, and a certain broadband effect is achieved, when the thickness of the material is 2.0mm, the bandwidth of R < -10dB is about 3.92GHz, and at 14.96G Hz, the maximum value of the reflectivity is about-22.81 dB (the absorptivity is about 99.48%). With increasing thickness, the maximum value of the reflectivity is about-13.64 dB (absorption is about 95.67%) at 13.04G Hz when the thickness is 2.4 mm.
C. For La prepared in example 2 0.2 Ca 1.8 Fe 2 O 5 CalculatingThe reflectivity R of the single-layer wave-absorbing material with the thickness of 2.0mm,2.2mm,2.4mm, 2.6mm and 2.8mm is simulated, and the result is shown in fig. 5:
from the figure, it can be seen that: the minimum reflectance peak is less than-10 dB (absorption greater than 90%) at all thicknesses, and the bandwidth of R < -10dB is wide, with good broadband effects, the bandwidth of R < -10dB is about 4GHz when the material thickness is 2.0mm, the minimum reflectance peak is about-20.12 dB (absorption about 99.03%) at 12.72GHz, the bandwidth of R < -10dB is about 3.36GHz when the material thickness is 2.2mm, the minimum reflectance peak is about-41.64 dB (absorption about 99.99%) at 11.6GHz, the bandwidth of R < -10dB is about 3.36GHz when the material thickness is 2.4mm, the minimum reflectance peak is about-24.79 dB (absorption about 99.67%) at 10.4GHz, the bandwidth of R < -10dB is about 3.36GHz when the material thickness is 2.4mm, the minimum reflectance peak is about-24.79 dB (absorption about 99.67%) at 9.52GHz, the bandwidth of R < -10dB is about-22.55% when the material thickness is 2.6mm, the minimum reflectance peak is about 3.36GHz, the absorption about 8.55% when the material thickness is 2.6 mm.
D. For La prepared in example 3 0.3 Ca 1.7 Fe 2 O 5 The calculated and simulated reflectivities R of the single-layer wave-absorbing material with the thicknesses of 1.6mm,1.8mm,2.0mm,2.2mm and 2.4mm are shown in FIG. 6:
from the figures, it can be seen that: the minimum reflectance peak is less than-10 dB (absorption greater than 90%) at all thicknesses, the bandwidth of R < -10dB is about 3.2GHz at a material thickness of 1.6mm, and the maximum reflectance is about-14.91 dB (absorption of about 96.77%) at 12.24 GHz. With increasing thickness, the maximum value of the reflectivity is about-14.51 dB (the absorption is about 96.46%) at 11.04GHz when the thickness is 1.8 mm.
E. The reflection rate loss condition of the wave-absorbing materials prepared in the embodiments 1 to 3 and the comparative example 1 is detected when the thickness is 2.4 mm:
the results are shown in FIG. 2: the minimum reflectivity peak value of the LaCaFeO material moves to a high-frequency region, the reflectivity peak value is increased and then reduced along with the increase of the La content, the La content is 0,0.1 and 0.2, the minimum reflectivity peak values are all less than-10 dB (the absorptivity is more than 90%), when the La content is 0,0.1,0.2 and 0.3, the frequencies of the reflectivity loss resonance peaks of the powder are respectively 14.32GHz,13.2GHz,11.6GHz and 8.4GHz, the corresponding reflectivity peak values are-12.06 dB, -14.91dB, -41.64dB and-9.62 dB, and the effective bandwidths of R < -10dB are respectively 0.8GHz,2.32GHz,3.36Ghz and 0GHz. The data can show that the powder has certain wave-absorbing bandwidth and wave-absorbing performance in the frequency band of 2-18 GHz.
As is clear from examples 1 to 3 and comparative example 1, the present invention is obtained by adding Ca 2 Fe 2 O 5 La element is doped in the material, so that the wave absorbing performance of the material is further improved.
The embodiments show that the invention provides a LaCaFeO wave-absorbing material, which can absorb electromagnetic waves in a 2-18GHz microwave band, has wide absorption band and high absorption efficiency (more than 90%), has higher oxide calcination temperature, has certain thermal stability compared with an alloy powder material, and has good oxidation resistance because the material is calcined in the air atmosphere and fully reacts with oxygen atoms in the air; the invention provides a preparation method of the LaCaFeO wave-absorbing material, the wave-absorbing material can be obtained through gelation reaction, pre-sintering and calcination, the preparation process is simple, and the preparation method is suitable for large-scale production.
It should be noted that, in this document, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.
The above examples are only intended to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. The LaCaFeO wave-absorbing material is characterized in that the molecular formula of the LaCaFeO wave-absorbing material is La x Ca y Fe 2 O 5 Wherein x is more than 0 and less than or equal to 0.3, and y is more than or equal to 1.7 and less than or equal to 2.
2. A preparation method of a LaCaFeO wave-absorbing material is characterized by comprising the following steps:
(1) Fully mixing metal nitrates of calcium, iron and lanthanum with a citric acid solution, stirring to carry out a gelation reaction, and obtaining gel for later use;
(2) And pre-burning the gel, and then heating and calcining to obtain the LaCaFeO wave-absorbing material.
3. The preparation method of the LaCaFeO wave-absorbing material according to claim 2, characterized in that: the molar ratio of the total molar amount of metal ions in the metal nitrate to the citric acid in the citric acid solution is 1: 1.2.
4. The preparation method of the LaCaFeO wave-absorbing material according to claim 2, characterized in that: the mass concentration of the citric acid solution is 36.23-50.71%.
5. The preparation method of the LaCaFeO wave-absorbing material according to claim 2, characterized in that: the temperature for the gelation reaction in the step (1) is 85 ℃, and the time is 3-5h.
6. The preparation method of the LaCaFeO wave-absorbing material according to claim 2, characterized in that: the rotating speed of stirring in the step (1) is 260-360r/min.
7. The preparation method of the LaCaFeO wave-absorbing material according to claim 2, characterized in that: in the step (2), the gel is dried before pre-sintering.
8. The method for preparing LaCaFeO wave-absorbing material according to claim 7, wherein: the drying mode is drying for 12-24h at the temperature of 80-130 ℃.
9. The preparation method of the LaCaFeO wave-absorbing material according to claim 2, characterized in that: the pre-sintering temperature in the step (2) is 400 ℃, and the pre-sintering time is 1h.
10. The preparation method of the LaCaFeO wave-absorbing material according to claim 2, characterized in that: the calcining temperature in the step (2) is 800 ℃, and the calcining time is 20h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211529019.6A CN115784317A (en) | 2022-11-30 | 2022-11-30 | LaCaFeO wave-absorbing material and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211529019.6A CN115784317A (en) | 2022-11-30 | 2022-11-30 | LaCaFeO wave-absorbing material and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115784317A true CN115784317A (en) | 2023-03-14 |
Family
ID=85444415
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211529019.6A Pending CN115784317A (en) | 2022-11-30 | 2022-11-30 | LaCaFeO wave-absorbing material and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115784317A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116395750A (en) * | 2023-03-27 | 2023-07-07 | 桂林电子科技大学 | SmCaFeO wave-absorbing material and preparation method thereof |
| CN116534902A (en) * | 2023-03-27 | 2023-08-04 | 桂林电子科技大学 | PrCaFeO wave-absorbing material and preparation method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101746834A (en) * | 2009-12-19 | 2010-06-23 | 山西大学 | Preparation method of perovskite composite oxide La1-xCaxFeO3 superfines |
| CN110550944A (en) * | 2019-09-26 | 2019-12-10 | 桂林电子科技大学 | BaLaFeO wave-absorbing material and preparation method thereof |
| CN111892093A (en) * | 2020-08-12 | 2020-11-06 | 桂林电子科技大学 | Microwave absorbing material and preparation method thereof |
| CN113573561A (en) * | 2021-06-16 | 2021-10-29 | 南京航空航天大学 | Perovskite type electromagnetic wave absorption material and preparation method thereof |
| CN114715947A (en) * | 2022-05-07 | 2022-07-08 | 桂林电子科技大学 | SrNdMnO wave absorbing material and preparation method thereof |
-
2022
- 2022-11-30 CN CN202211529019.6A patent/CN115784317A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101746834A (en) * | 2009-12-19 | 2010-06-23 | 山西大学 | Preparation method of perovskite composite oxide La1-xCaxFeO3 superfines |
| CN110550944A (en) * | 2019-09-26 | 2019-12-10 | 桂林电子科技大学 | BaLaFeO wave-absorbing material and preparation method thereof |
| CN111892093A (en) * | 2020-08-12 | 2020-11-06 | 桂林电子科技大学 | Microwave absorbing material and preparation method thereof |
| CN113573561A (en) * | 2021-06-16 | 2021-10-29 | 南京航空航天大学 | Perovskite type electromagnetic wave absorption material and preparation method thereof |
| CN114715947A (en) * | 2022-05-07 | 2022-07-08 | 桂林电子科技大学 | SrNdMnO wave absorbing material and preparation method thereof |
Non-Patent Citations (3)
| Title |
|---|
| T.L. PHAN等: "Crystalline and Electronic Structures and Magnetic andElectrical Properties of La-Doped Ca2Fe2O5 Compounds", 《JOURNAL OF ELECTRONIC MATERIALS》, vol. 47, no. 1, pages 189 - 65 * |
| 杜卫民: "《纳米材料化学的理论与工程应用研究》", 31 May 2018, 电子科技大学出版社, pages: 263 * |
| 赵玛等: "纳米晶La0.8Sr0.2FeO3气敏元器件的制备与乙醇敏感特性", 《稀有金属材料与工程》, vol. 36, no. 05, pages 899 - 902 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116395750A (en) * | 2023-03-27 | 2023-07-07 | 桂林电子科技大学 | SmCaFeO wave-absorbing material and preparation method thereof |
| CN116534902A (en) * | 2023-03-27 | 2023-08-04 | 桂林电子科技大学 | PrCaFeO wave-absorbing material and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115784317A (en) | LaCaFeO wave-absorbing material and preparation method thereof | |
| Feng et al. | Fabrication of NiFe 2 O 4@ carbon fiber coated with phytic acid-doped polyaniline composite and its application as an electromagnetic wave absorber | |
| CN110550944A (en) | BaLaFeO wave-absorbing material and preparation method thereof | |
| CN111892093B (en) | Microwave absorbing material and preparation method thereof | |
| CN114715947A (en) | SrNdMnO wave absorbing material and preparation method thereof | |
| CN112456562B (en) | Ferrite-based composite material and preparation method and application thereof | |
| CN112408409A (en) | High-temperature-resistant high-entropy wave-absorbing ceramic and preparation method and application thereof | |
| CN113956027A (en) | Ferrite wave-absorbing material and preparation method thereof | |
| CN114634208A (en) | Oxide composite material and preparation method and application thereof | |
| CN115650309A (en) | Cerium-doped barium ferrite wave-absorbing material and preparation method thereof | |
| CN111484080A (en) | Neodymium-doped praseodymium-manganese oxide wave-absorbing powder material and preparation method thereof | |
| CN103242037B (en) | Hexagonal ferrite material with high magnetic loss in L wave band and preparation method thereof | |
| CN110340376B (en) | Flower-shaped nickel wire wave-absorbing material and preparation method thereof | |
| CN114956192A (en) | Lanthanum-cobalt co-doped barium ferrite dual-waveband wave-absorbing powder material and preparation method thereof | |
| CN113511687B (en) | Wave-absorbing material and preparation method thereof | |
| Veisi et al. | Magnetic properties, structural studies and microwave absorption performance of Ba0. 5Sr0. 5CuxZrxFe12-2xO19/Poly Ortho-Toluidine (X= 0.2, 0.4, 0.6, 0.8) ceramic nanocomposites | |
| CN114455630B (en) | Multi-band composite electromagnetic wave absorbing material and preparation method and application thereof | |
| CN116534902A (en) | PrCaFeO wave-absorbing material and preparation method thereof | |
| CN116395750A (en) | SmCaFeO wave-absorbing material and preparation method thereof | |
| CN110517723B (en) | Preparation method of high-permeability GHz-band absorbing material | |
| CN106957985A (en) | A kind of DyHoFe electromagnetic wave absorbing materials and preparation method thereof | |
| CN117460238A (en) | Wave-absorbing material and preparation method thereof | |
| CN117658227A (en) | PrNdCoO wave-absorbing material and preparation method thereof | |
| CN110922181A (en) | Flaky ceramic wave-absorbing material and preparation method thereof | |
| CN110922180A (en) | Multi-iron wave-absorbing material and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |