CN100574598C - W type ferrite electromagnetic-wave absorbent and preparation method thereof - Google Patents
W type ferrite electromagnetic-wave absorbent and preparation method thereof Download PDFInfo
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- CN100574598C CN100574598C CNB2007101919028A CN200710191902A CN100574598C CN 100574598 C CN100574598 C CN 100574598C CN B2007101919028 A CNB2007101919028 A CN B2007101919028A CN 200710191902 A CN200710191902 A CN 200710191902A CN 100574598 C CN100574598 C CN 100574598C
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Abstract
The invention discloses a kind of W type ferrite electromagnetic-wave absorbent and preparation method thereof, with barium, cobalt, the nitrate of iron, organic acid, saturated low-carbon alcohols, water is primary raw material, the mol ratio of raw material is: Ba/Fe=1: 14～17, Ba/Co=1: 1～2, organic acid/Ba=10～40: 1, saturated low-carbon alcohols/organic acid=0～3: 1, lanthanum can mix in raw material, nickel, titanium, manganese, copper, the cerium transition metal, pass through sol-gel process, through pre-burning, roasting makes under the high temperature, the present invention is complexing agent with the organic acid, saturated small molecular alcohol is a dispersant, crystallization is evenly complete, the electromagnetic performance excellence, has higher dielectric constant, become the absorption efficiency height, advantages such as the thin and bandwidth of coating are easy to processing and produce in enormous quantities, are the ferritic Perfected process of preparation.
Description
Technical field
The present invention relates to electromagnetic-wave absorbent and preparation technology thereof, relate in particular to a kind of W type ferrite electromagnetic-wave absorbent and preparation method thereof.
Background technology
In the magnetizing mediums absorbing material, hexagonal ferrite is better than spinel type ferrite, and the W type is compared with other several types and more possessed the excellent absorption characteristic in the hexagonal ferrite.W type ferrite molecular formula is BaMe
2Fe
16O
27(Me is the metal ion of divalence), have inexpensive, high resistance, chemical property is stable and the characteristics such as magnetic performance of various excellences, be used as aspects such as permanent magnetic material, high-density perpendicular magnetic recording medium widely, particularly in recent years along with the development of stealth technology, electromangnetic spectrum, ferrite is developed rapidly because of its good microwave absorbing property.
When electromagnetic wave passes through absorbing material, utilize the electromagnetic consumable of absorbent, make electromagnetic wave energy be converted into other forms of energy, it is farthest absorbed in medium.The W type ferrite has higher magnetic permeability and conductivity under high frequency, so have higher dielectric property.This material all is plural form at the relative permeability and the relative conductivity of microwave frequency band, can produce dielectric loss again so it can produce magnetic loss, and wherein the magnetic consume is main consume.The magnetic loss of W type hexagonal ferrite mainly relies on magnetic polarization mechanism decay such as magnetic hysteresis loss, domain wall resonance and natural resonance, aftereffect loss, absorbs electromagnetic wave; The electrical loss of W type hexagonal ferrite mainly is meant dielectric loss.
The ferritic main method of preparation has physics method, chemical precipitation method, hydro thermal method, micro emulsion method etc. at present, but these methods all can't solve the homogeneity question of mixing, thereby has influenced ferritic electromagnetic performance.Patent CN 1644546A employing citrate sol-gel method prepares the barium ferrite layer at porous glass phase microparticle surfaces makes it produce certain absorption to electromagnetic wave, but there are certain degree of difficulty in the moulding of wave absorbing agent and processing.Patent CN 1657585A has proposed the method at the silicon carbide coated with barium ferrite film, though certain stealthy ability is arranged, can its application region be at region of ultra-red, but have good stealth effect not appear in the newspapers in higher frequency.Patent CN 1807537A has adopted the in-situ deposition method to prepare composite wave-suction material, and the time-consuming and complex procedures of producing has limited the production in enormous quantities of material greatly.Patent CN1905079A mentions the material that increases the transition matching section between polyurethane wave-absorbing material and Ferrite Material, can have good absorbing property at high frequency, but the thickness 50mm ± 2mm of coating, the emphasis of considering is not in the raising of wave absorbing agent absorbing property, but its matching performance of main consideration.
Summary of the invention
One object of the present invention is to provide a kind of W type ferrite of electromagnetic performance excellence, makes it have good absorbing property in 30MHz～40000MHz scope.
Another purpose of the present invention is to provide a kind of W type ferrite and preparation method thereof, and is evenly complete with the W type ferrite crystallization of this method preparation.
W type ferrite electromagnetic-wave absorbent of the present invention is that nitrate, organic acid, saturated low-carbon alcohols, the water with barium, cobalt, iron is primary raw material, the mol ratio of raw material is: Ba/Fe=1: 14～17, Ba/Co=1: 1～2, organic acid/Ba=10～40: 1, saturated low-carbon alcohols/organic acid=0～3: 1.
W type ferrite of the present invention and preparation method thereof is to may further comprise the steps successively:
A, the nitrate of barium, cobalt, iron is dissolved in the distilled water stirs, obtain clear solution;
B, organic acid added in the solution of steps A and stir, obtain clear solution;
Stir in C, the solution, obtain homogeneous solution saturated low-carbon alcohols adding step B;
D, ammoniacal liquor is added in the solution of step C preparation, make it to mix fully, regulator solution pH=7 is to neutral;
E, the solution of step D is placed 80～100 ℃ slowly evaporation 2～6 hours of water-bath, in 110～150 ℃ baking oven, dry again, until the xerogel that forms black;
F, with xerogel in 450 ℃ of pre-burnings 2～6 hours, organic substance is decomposed fully;
G, the sample after the pre-burning is placed Muffle furnace, be warming up to 1000～1800 ℃ with the speed of 5 ℃ of per minutes, be incubated 2～6 hours, with the stove cooling, obtain particle diameter and be 1～10 micron ferrite, crystalline phase is single W type.
The present invention is complexing agent with the organic acid, saturated small molecular alcohol is a dispersant, and by alkali lye adjusting pH value, obtain colloidal sol, and oven dry obtains dry gel, high-temperature calcination obtains the ferrite of crystalline phase homogeneous again, have raw molecule mixing, good dispersion, reaction temperature is low, and than low 300～500 ℃ of this crystal formation ferrite preparation temperature in the prior art, product is formed and substitutional ion is controlled easily, doped chemical is raw material with the metal nitrate, employing sol-gel process preparation, it is little to make its ferrite that obtains have a powder particle, and particle size distribution is 1～50 micron; Narrow particle size distribution all is the hexagonal plate structure of perfect crystalline, is easy to processing and produces in enormous quantities, has higher dielectric constant, becomes the absorption efficiency height, coating is thin and the absorbing material of advantage such as bandwidth, is the ferritic Perfected process of preparation.
The present invention also can obtain the ferrite particulate of different absorbing properties by mix different elements and content thereof.
Description of drawings
The present invention is further described below in conjunction with the drawings and specific embodiments.
Fig. 1 is X-ray diffraction (XRD) spectrogram of the product of embodiment 1 preparation.
Fig. 2 handles ESEM (SEM) photo of the product that obtains down for sintering temperature among the embodiment 2.
Fig. 3 is graph of relation of Ferrite Material electromagnetism consume tangent and frequency for embodiment 4.
Fig. 4 is graph of relation of Ferrite Material electromagnetism consume tangent and frequency for embodiment 6.
Embodiment
W type ferrite electromagnetic-wave absorbent is a primary raw material with nitrate, organic acid, saturated low-carbon alcohols, the water of barium, cobalt, iron, the mol ratio of raw material is: Ba/Fe=1: 14～17, Ba/Co=1: 1～2, organic acid/Ba=10～40: 1, saturated low-carbon alcohols/organic acid=0～3: 1.For making the ferrite electromagnetic-wave absorbent of different absorbing properties, lanthanum, nickel, titanium, manganese, copper, cerium transition metal, wherein Ba/Ni=1 can mix in raw material: 0.5～2, and Ba/Ti=1: 0.1～0.5, Ba/Mn=1: 0.1～1, Ba/Ce=1: 0.1～1.
The present invention is a complexing agent with organic acid (mannocarolose, mannose, glucose, malic acid, butanedioic acid, citric acid, lactic acid, oxalic acid etc.), and saturated small molecular alcohol (diethylene glycol (DEG), ethylene glycol, triethylene glycol etc.) is a dispersant, prepares by sol-gel process.Concrete steps are: the nitrate of the nitrate of barium, cobalt, iron and doping lanthanum, nickel, titanium, manganese, copper, cerium transition metal is dissolved in the distilled water stirs, obtain clear solution; Organic acid added in the solution stir, saturated low-carbon alcohols is added in the solution stir again, obtain homogeneous solution; Ammoniacal liquor is added in the solution for preparing, make it to mix fully, regulator solution pH=7 is to neutral; Then neutral solution is placed 80～100 ℃ water-bath slowly to evaporate 2～6 hours, in 110～150 ℃ baking oven, dry again, until the xerogel that forms black; In 450 ℃ of pre-burnings 2～6 hours, organic substance is decomposed fully xerogel; At last the sample after the pre-burning is placed Muffle furnace, be warming up to 1000～1800 ℃ with the speed of 5 ℃ of per minutes, the roasting insulation is 2～6 hours under the high temperature, with the stove cooling, obtains particle diameter and be 1～10 micron ferrite, and crystalline phase is single W type.
The present invention regulates ferritic electromagnetic parameter by doping lanthanum, nickel, titanium, manganese, copper, cerium different metal element and content, thereby obtain the product of different performance requirement, its complex dielectric permittivity real part is 4～5, the complex dielectric permittivity imaginary part is 0.1～1, the complex permeability real part is 0.8～1.2, the complex permeability imaginary part is 0.3～0.4, and consume angle tangent value is 0.3～1.5.
Below by 6 embodiment the present invention is described in detail again, agents useful for same is a chemical pure among the embodiment, but not thereby limiting the invention.
Embodiment 1
Step 1: with Ba (NO
3)
2, Co (NO
3)
26H
2O and Fe (NO
3)
39H
2O is dissolved in the distilled water, stirs, and obtains clear solution.Material molar ratio: Ba/Co/Fe=1: 2: 16.
Step 2: citric acid is added in the solution in (1) step, stir, obtain clear solution.Material molar ratio: citric acid/Ba=19: 1.
Step 3: ethylene glycol is added in the solution in (2) step, stir, obtain homogeneous solution.Material molar ratio: ethylene glycol/citric acid=1: 1.
Step 4: ammoniacal liquor is added in the solution of (3) step preparation, make it to mix fully, regulator solution is to neutrality, pH=7.
Step 5: place 90 ℃ water-bath slowly to evaporate 2h the solution in (4) step, in 130 ℃ baking oven, dry again, until the xerogel that forms black.
Step 6: in 450 ℃ of pre-burning 3h, organic substance is decomposed fully xerogel.
Step 7: the sample after the pre-burning is placed Muffle furnace, be warming up to 1500 ℃ with the speed of 5 ℃/min, insulation 3h with the stove cooling, obtains particle diameter and is 1～10 micron ferrite, and crystalline phase is single W type.
Fig. 1 is the ferritic XRD spectra of preparation, the ferrite that the sample of preparation is a W crystal formation ferrite, crystal formation is single.Embodiment 2
Step 1: with Ba (NO
3)
2, Co (NO
3)
26H
2O and Fe (NO
3)
39H
2O is dissolved in the distilled water, stirs, and obtains clear solution.Material molar ratio: Ba/Co/Fe=1: 2: 15.2.
Step 7: the sample after the pre-burning is placed Muffle furnace, be warming up to 1800 ℃ with the speed of 5 ℃/min, insulation 5h, with the stove cooling, obtaining crystalline phase is single W type ferrite.
Fig. 2 is the ferritic SEM photo of preparation, and the sample particle diameter of preparation is 1～5 micron, is evenly distributed.
Embodiment 3
Step 1: with Ba (NO
3)
2, Co (NO
3)
26H
2O, Ni (NO
3)
26H
2O and Fe (NO
3)
39H
2O is dissolved in the distilled water, stirs, and obtains clear solution.Material molar ratio: Ba/Co/Ni/Fe=1: 1: 1: 16.
Step 7: the sample after the pre-burning is placed Muffle furnace, be warming up to 1000 ℃ with the speed of 5 ℃/min, insulation 3h with the stove cooling, obtains particle diameter and is 1～10 micron ferrite, and crystalline phase is single W type.
Step 1: with Ba (NO
3)
2, Co (NO
3)
26H
2O, Mn (NO
3)
2And Fe (NO
3)
39H
2O is dissolved in the distilled water, stirs, and obtains clear solution.Material molar ratio: Ba/Co/Mn/Fe=1: 1: 1: 16.
Step 7: the sample after the pre-burning is placed Muffle furnace, be warming up to 1280 ℃ with the speed of 5 ℃/min, insulation 4h with the stove cooling, obtains particle diameter and is 1～10 micron ferrite, and crystalline phase is single W type, has good electromagnetic performance.
Fig. 3 is the ferrite electromagnetism consume tangent of preparation and the graph of relation of frequency, and two maximum consume peaks appear respectively in sample when 5.5GHz and 13GHz, and consume angle tangent reaches 0.45.
Embodiment 5
Step 1: with step 1 among the embodiment 1.
Step 2: citric acid is added in the solution in (1) step, stir, obtain clear solution.Material molar ratio: citric acid/Ba=38: 1
Step 3～step 6: with step 3～step 6 among the embodiment 1.
Step 7: the sample after the pre-burning is placed Muffle furnace, be warming up to 1400 ℃ with the speed of 5 ℃/min, insulation 6h with the stove cooling, obtains particle diameter and is 1～10 micron ferrite, and crystalline phase is single W type.
Step 1～step 6: with step 1～step 6 among the embodiment 1.
Step 7: the sample after the pre-burning is placed Muffle furnace, be rapidly heated to 1300 ℃, insulation 2h with stove cooling, obtains particle diameter and is 1～10 micron ferrite, and crystalline phase is single W type.
Fig. 4 is the graph of relation of ferritic electromagnetism consume tangent of preparation and frequency, and maximum consume peak appears in sample when 5GHz, and consume angle tangent reaches 0.58.
Claims (4)
1. W type ferrite electromagnetic-wave absorbent, it is characterized in that: this material is a primary raw material with the saturated low-carbon alcohols of nitrate, organic acid, diethylene glycol (DEG), ethylene glycol or triethylene glycol, the water of barium, cobalt, iron, the mol ratio of raw material is: Ba/Fe=1: 14～17, Ba/Co=1: 1～2, organic acid/Ba=10～40: 1, the saturated low-carbon alcohols/organic acid of diethylene glycol (DEG), ethylene glycol or triethylene glycol=0～3: 1; The preparation process of this material is followed successively by:
A, the nitrate of barium, cobalt, iron is dissolved in the distilled water stirs, obtain clear solution;
B, organic acid added in the solution of steps A and stir, obtain clear solution;
Stir in C, the solution, obtain homogeneous solution the saturated low-carbon alcohols adding of diethylene glycol (DEG), ethylene glycol or triethylene glycol step B;
D, ammoniacal liquor is added in the solution of step C preparation, make it to mix fully, regulator solution pH=7 is to neutral;
E, the solution of step D is placed 80～100 ℃ slowly evaporation 2～6 hours of water-bath, in 110～150 ℃ baking oven, dry again, until the xerogel that forms black;
F, with xerogel in 450 ℃ of pre-burnings 2～6 hours, organic substance is decomposed fully;
G, the sample after the pre-burning is placed Muffle furnace, be warming up to 1000～1800 ℃ with the speed of 5 ℃ of per minutes, be incubated 2～6 hours, with the stove cooling, obtain particle diameter and be 1～10 micron ferrite, crystalline phase is single W type.
2. W type ferrite electromagnetic-wave absorbent according to claim 1, it is characterized in that: the lanthanum that in described raw material, mixes, nickel, titanium, manganese, copper, cerium transition metal, wherein Ba/Ni=1: 0.5～2, Ba/Ti=1: 0.1～0.5, Ba/Mn=1: 0.1～1, Ba/Ce=1: 0.1～1.
3. W type ferrite electromagnetic-wave absorbent according to claim 1, it is characterized in that: in steps A, the nitrate of doping lanthanum, nickel, titanium, manganese, copper, cerium transition metal nitrate and barium, cobalt, iron is dissolved in the distilled water and stirs, obtain clear solution.
4. W type ferrite electromagnetic-wave absorbent according to claim 1, it is characterized in that: the ferrite complex dielectric permittivity real part that step G prepares is 4～5, the complex dielectric permittivity imaginary part is 0.1～1, the complex permeability real part is 0.8～1.2, the complex permeability imaginary part is 0.3～0.4, and consume angle tangent value is 0.3～1.5.
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| CN101452756B (en) * | 2008-09-19 | 2011-04-13 | 西北工业大学 | Cerium-doped nanometer barium ferrite thin film and method for making same |
| CN102417349B (en) * | 2011-09-05 | 2013-07-17 | 常州大学 | Samarium-ferrite radar absorbing material and preparation method thereof |
| CN102863207B (en) * | 2012-09-10 | 2014-06-18 | 常州大学 | Method for preparing ferrite film with single crystal template |
| CN103131384B (en) * | 2013-02-28 | 2014-06-04 | 湖南大学 | Nanometer composite wave absorbing powder having low density and porous structure, and its preparation method |
| CN107792889A (en) * | 2017-11-02 | 2018-03-13 | 桂林电子科技大学 | A kind of strontium cobalt W type hexad ferrite materials and preparation method thereof |
| CN107855074A (en) * | 2017-11-28 | 2018-03-30 | 桂林电子科技大学 | A kind of particle diameter thinning method that metal oxide materials are prepared using nitrate as raw material |
| CN108998689B (en) * | 2018-07-03 | 2020-07-10 | 中国科学院金属研究所 | High-temperature-resistant metal ceramic wave-absorbing material and preparation method thereof |
| CN109037961B (en) * | 2018-07-11 | 2020-05-26 | 长江大学 | Nickel-zinc ferrite wave-absorbing material and preparation method thereof |
| CN111099888A (en) * | 2019-12-31 | 2020-05-05 | 天长市中德电子有限公司 | Preparation method of wave-absorbing ferrite |
| CN112175224B (en) * | 2020-10-14 | 2022-10-14 | 泉州师范学院 | Method for improving stretching and folding resistance of FDM 3D printing TPU shoe material |
| CN114538522A (en) * | 2022-01-25 | 2022-05-27 | 深圳市信维通信股份有限公司 | Aluminum-substituted high-crystallinity M-type ferrite and preparation method thereof |
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