CN108558387B - Single-phase multi-iron microwave absorbing material and preparation method thereof - Google Patents

Single-phase multi-iron microwave absorbing material and preparation method thereof Download PDF

Info

Publication number
CN108558387B
CN108558387B CN201810035771.2A CN201810035771A CN108558387B CN 108558387 B CN108558387 B CN 108558387B CN 201810035771 A CN201810035771 A CN 201810035771A CN 108558387 B CN108558387 B CN 108558387B
Authority
CN
China
Prior art keywords
containing compound
microwave
phase
neodymium
absorbing material
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.)
Active
Application number
CN201810035771.2A
Other languages
Chinese (zh)
Other versions
CN108558387A (en
Inventor
孙书杰
王文燕
张�林
田永尚
肖振宇
李彦磊
赵志强
程念
房良
訾威
孙柱柱
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xinyang Normal University
Original Assignee
Xinyang Normal University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Xinyang Normal University filed Critical Xinyang Normal University
Priority to CN201810035771.2A priority Critical patent/CN108558387B/en
Publication of CN108558387A publication Critical patent/CN108558387A/en
Application granted granted Critical
Publication of CN108558387B publication Critical patent/CN108558387B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/26—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on ferrites
    • C04B35/2608—Compositions containing one or more ferrites of the group comprising manganese, zinc, nickel, copper or cobalt and one or more ferrites of the group comprising rare earth metals, alkali metals, alkaline earth metals or lead
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/26—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on ferrites
    • C04B35/2666—Other ferrites containing nickel, copper or cobalt
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/26—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on ferrites
    • C04B35/2675—Other ferrites containing rare earth metals, e.g. rare earth ferrite garnets
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0073—Shielding materials
    • H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C04B2235/3232—Titanium oxides or titanates, e.g. rutile or anatase
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/327—Iron group oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C04B2235/3275—Cobalt oxides, cobaltates or cobaltites or oxide forming salts thereof, e.g. bismuth cobaltate, zinc cobaltite
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3298—Bismuth oxides, bismuthates or oxide forming salts thereof, e.g. zinc bismuthate
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/658—Atmosphere during thermal treatment
    • C04B2235/6583—Oxygen containing atmosphere, e.g. with changing oxygen pressures
    • C04B2235/6585—Oxygen containing atmosphere, e.g. with changing oxygen pressures at an oxygen percentage above that of air
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/74—Physical characteristics
    • C04B2235/76—Crystal structural characteristics, e.g. symmetry
    • C04B2235/768—Perovskite structure ABO3
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance

Abstract

The invention discloses a single-phase multiferroic microwave absorbing material NdBi6Ti3(Fe1‑xCox)3O21(x is 0.25-0.3) and a preparation method thereof, the microwave absorbing material shows excellent multiferroic performance due to the symbiotic structural characteristics of layered perovskites and chemical modification by neodymium, and ferrite octahedron and cobalt oxygen octahedron structural units exist in the structure. Based on the physical properties, the material has good microwave absorption property in the microwave range of 2-18GHz, high absorption strength and wide absorption frequency band, and is far superior to the microwave absorption property of partial carbon/ferrite composite material; and the preparation method is simple to operate, short in experimental period, beneficial to large-scale production and wide in application prospect.

Description

Single-phase multi-iron microwave absorbing material and preparation method thereof
Technical Field
The invention relates to a microwave absorbing material and a preparation method thereof, in particular to a multiferroic microwave absorbing material with a single-phase layered perovskite symbiotic structure and a preparation method thereof, belonging to the technical field of functional materials.
Background
With the development of the electronic industry, problems about electromagnetic interference, information security, personnel security and the like become more and more prominent, wherein the problems about electromagnetic interference shielding and microwave absorption are always paid attention by scientists due to the existence of novel physical characteristics and potential commercial values. Ideal microwave absorbing materials are generally required to have good thermal stability, oxidation resistance, low density, wide absorption band and high absorption strength, and the most widely studied materials in this field are magnetic ferrite system materials because they have high resistance and excellent magnetic loss, but at the same time, they have disadvantages of being easily oxidized, easily agglomerated and high in density, thus hindering their practical use. Subsequently, scientists paid attention to the nanocomposite formed by compounding the carbon nanotube and the magnetic ferrite nanomaterial, and the nanocomposite has the advantages of high thermal stability, low density, high electrical conductivity and the like, can show excellent microwave absorption characteristics, and has a good potential application.
It is well known that electric and magnetic dipoles are two types of strong microwave absorbers. Multiferroic materials generally refer to materials that contain two or more basic ferroelectricities (ferroelectricity, ferromagnetism/antiferromagnetism, ferroelasticity, etc.) in the same phase. The magnetoelectric multiferroic material can simultaneously have ferroelectricity (electric dipole) and ferromagnetism/antiferromagnetism (magnetic dipole) in a single phase, and can also realize the conversion between electromagnetism by utilizing a coupling mechanism. These suggest that the magnetoelectric multiferroic material can simultaneously realize the absorption of microwaves by two types of microwave absorbers in a single-phase material, and is probably a type of microwave device material with good microwave absorption characteristics. Unfortunately, the research on the microwave absorption characteristics of magnetoelectric multiferroic materials has focused only on bismuth ferrite (BiFeO) having ferroelectricity and antiferromagnetism3) On the material. The bismuth ferrite nano material has been reported to have inherent microwave absorption characteristics, and the best reflection loss value is-17 dB, which is far higher than the reflection loss value of-30 dB of the carbon nano tube and magnetic ferrite nano composite material. Therefore, it is important to find the microwave absorption characteristics of other magnetoelectric multiferroic materials, and the research focus has been focused on by researchers.
Disclosure of Invention
In order to solve the technical problems, the invention provides a single-phase multiferroic microwave absorbing material and a preparation method thereof, and the single-phase characteristic of the material enables the preparation process of the material to be simple and is beneficial to large-scale application; the multiferroic material can simultaneously realize the microwave absorption of electric dipoles and magnetic dipoles, so that the material shows excellent microwave absorption characteristics.
The technical scheme of the invention is as follows:
the invention provides a single-phase multiferroic microwave absorbing material, which has a chemical formula shown as a formula (I):
NdBi6Ti3(Fe1-xCox)3O21(x＝0.25-0.3) (Ⅰ)。
furthermore, the structure of the material is a structure with a single-phase intergrowth layered perovskite layer, and the structure with the single-phase intergrowth layered perovskite layer is a single-phase structure with a disordered intergrowth state of four perovskite layers and five perovskite layers.
The single-phase multiferroic microwave absorbing material is Aurivillius phase bismuth layer-shaped perovskite oxide, and the value range of X is 0.25 to 0.3. In the range, the material is in a homogeneous phase five-layer and homogeneous phase four-layer perovskite structure conversion interval, and has the characteristic of disordered symbiotic structure of four and five perovskite layers. The structure belongs to a single-phase layer modulation phase structure, and ferrite octahedron and cobalt oxygen octahedron structure units exist in the structure, so that the material has excellent ferroelectricity and ferromagnetism; in addition, neodymium is adopted for chemical modification, so that the leakage current of the material can be reduced, and the physical performance of the material can be improved. Finally, the modulation structure material can show excellent ferroelectricity, dielectricity and ferromagnetism, and further shows excellent microwave absorption performance.
The invention also provides a preparation method of the single-phase multiferroic microwave absorbing material, which comprises the following steps:
(1) mixing n-butyl titanate, a bismuth-containing compound, a neodymium-containing compound, an iron-containing compound, a cobalt-containing compound and a complexing agent in a dilute nitric acid solution according to a stoichiometric ratio to obtain a mixed solution;
(2) adjusting the pH value of the mixed solution obtained in the step (1) to be neutral by using ammonia water, stirring to obtain a clear solution, and then evaporating and presintering the clear solution to obtain primary powder;
(3) and (3) tabletting and forming the primary powder obtained in the step (2), and carrying out hot-pressing sintering to obtain the single-phase multiferroic microwave absorbing material.
In a still further aspect of the present invention,
in the step (1), the molar ratio of titanium, bismuth, neodymium, iron and cobalt in the n-butyl titanate, the bismuth-containing compound, the neodymium-containing compound, the iron-containing compound and the cobalt-containing compound is 3:6:1 (3-3x) 3x, and x is 0.25-0.3.
In the step (1), the bismuth-containing compound is bismuth nitrate pentahydrate, the neodymium-containing compound is neodymium nitrate hexahydrate, the iron-containing compound is ferric nitrate nonahydrate, the cobalt-containing compound is cobalt nitrate hexahydrate, and the complexing agent is citric acid and ethylenediamine tetraacetic acid.
In the step (2), the pre-sintering temperature is 700-750 ℃, and the pre-sintering time is 2-5 h.
In the step (3), the sintering temperature is 850-900 ℃, the sintering time is 3-6h, the sintering atmosphere is a mixed atmosphere formed by oxygen and argon according to the volume ratio of (3-5):1, and the hot-pressing pressure in the sintering process is 12-13 MPa; wherein the volume ratio of oxygen to argon in the mixed atmosphere is optimally 4:1, and the hot pressing pressure in the sintering process is optimally 12.56 MPa.
The single-phase multiferroic microwave absorbing material NdBi of the invention6Ti3(Fe1-xCox)3O21(x is 0.25-0.3) can be used as a good microwave absorbent, and the microwave absorption performance parameters can be analyzed and measured by a vector network analyzer and calculated by a coaxial line theory.
The beneficial technical effects of the invention are as follows: the invention provides a single-phase multiferroic microwave absorbing material NdBi with a layered perovskite intergrowth structure6Ti3(Fe1-xCox)3O21(x is 0.25-0.3), the material is chemically modified by neodymium due to the characteristic of a layered perovskite symbiotic structure, and ferrite octahedron and cobalt oxygen octahedron exist in the structureThe bulk structural units interact and show excellent dielectricity, ferroelectricity and ferromagnetism. Based on the physical properties, the material has good microwave absorption property in the microwave range of 2-18GHz, high absorption strength (the optimal reflection loss peaks are all lower than-30 dB), wide absorption frequency band (the frequency band width with the reflection loss lower than-20 dB is higher than 10GHz), and far better microwave absorption property than that of partial carbon/ferrite composite material; and the preparation method is simple to operate, short in experimental period, beneficial to large-scale production and wide in application prospect.
Drawings
FIG. 1 shows NdBi in examples of the present invention6Ti3(Fe1-xCox)3O21(X-0.2-0.4) X-ray pattern of material;
FIG. 2 shows NdBi in examples of the present invention6Ti3(Fe1-xCox)3O21(x is 0.0-1.0) a schematic structural diagram and a physical diagram of the material;
FIG. 3 shows NdBi in examples of the present invention6Ti3(Fe1-xCox)3O21(x ═ 0.25) the ferroelectric and ferromagnetic results of the material;
FIG. 4 shows NdBi in example 1 of the present invention6Ti3(Fe1-xCox)3O21(x ═ 0.25) results for electromagnetic parameters for a material thickness of 3.3 mm;
FIG. 5 shows NdBi in example 1 of the present invention6Ti3(Fe1-xCox)3O21(x ═ 0.25) microwave reflection loss results for material thickness 3.3 mm;
FIG. 6 shows NdBi in example 1 of the present invention6Ti3(Fe1-xCox)3O21(x ═ 0.25) relationship between material coating thickness d and microwave reflection loss;
FIG. 7 shows NdBi in example 2 of the present invention6Ti3(Fe1-xCox)3O21(x ═ 0.3) results for electromagnetic parameters at a material thickness of 3.3 mm;
FIG. 8 is an embodiment of the present inventionNdBi in example 26Ti3(Fe1-xCox)3O21(x ═ 0.3) microwave reflection loss results for a material thickness of 3.3 mm.
Detailed Description
In order to make the technical means of the present invention clearer and to make the technical means of the present invention capable of being implemented according to the content of the specification, the following detailed description of the embodiments of the present invention is made with reference to the accompanying drawings and examples, which are provided for illustrating the present invention and are not intended to limit the scope of the present invention.
The embodiment of the application discloses a single-phase multiferroic microwave absorbing material as shown in a formula (I):
NdBi6Ti3(Fe1-xCox)3O21(x＝0.25-0.3) (Ⅰ)。
the embodiment of the application provides a preparation method of a single-phase multiferroic microwave absorbing material as shown in a formula (I), and the preparation method comprises the following steps:
(1) mixing n-butyl titanate, a bismuth-containing compound, a neodymium-containing compound, an iron-containing compound, a cobalt-containing compound and a complexing agent in a dilute nitric acid solution according to a stoichiometric ratio to obtain a mixed solution; wherein the molar ratio of titanium, bismuth, neodymium, iron and cobalt in the n-butyl titanate, the bismuth-containing compound, the neodymium-containing compound, the iron-containing compound and the cobalt-containing compound is 3:6:1 (3-3x) 3x, and x is 0.25-0.3; the bismuth-containing compound is bismuth nitrate pentahydrate, the neodymium-containing compound is neodymium nitrate hexahydrate, the iron-containing compound is ferric nitrate nonahydrate, the cobalt-containing compound is cobalt nitrate hexahydrate, and the complexing agent is citric acid and ethylenediamine tetraacetic acid.
(2) Adjusting the pH value of the mixed solution obtained in the step (1) to be neutral by using ammonia water, stirring to obtain a clear solution, then putting the clear solution into a crucible and evaporating on a heating table to dryness; pre-burning the material obtained after drying by distillation, wherein the pre-burning temperature is 700-750 ℃, the pre-burning time is 2-5 h, and the pre-sintered material is ground to obtain primary powder;
(3) tabletting the primary powder obtained in the step (2) on a tabletting machine through a mould; then hot-pressing and sintering by using a hot-pressing furnace, wherein the hot-pressing sintering temperature is 850-900 ℃, the sintering time is 3-6h, the sintering atmosphere is a mixed atmosphere formed by oxygen and argon according to the volume ratio of (3-5):1, the optimal volume ratio of oxygen and argon is 4:1, and in the sintering process, the hot-pressing pressure condition is always kept at 12-13MPa, and the optimal pressure condition is kept at 12.56 MPa; and obtaining the single-phase multiferroic microwave absorbing material after hot-pressing sintering.
The single-phase multiferroic microwave absorbing material is Aurivillius phase bismuth layer-structured oxide, as shown in figure 1. The value range of X is 0.25 to 0.3, and in the range, the material is in a homogeneous phase five-layer and homogeneous phase four-layer perovskite structure transformation interval and has the disordered symbiotic structural characteristics of four and five perovskite layers as shown in the attached figure 2. Although the material has a perovskite layer intergrowth structure, the material is still a single-phase material, and the intergrowth structure is formed by self-assembly in the preparation process. Therefore, the preparation process of the material is relatively simple, the experimental period is short, and the material is beneficial to large-scale production. The microwave material with the single-phase layer modulation phase structure has the advantages that ferrite octahedron and cobalt oxygen octahedron structural units exist in the structure of the microwave material and interact with each other, neodymium chemical modification is performed on the microwave material, so that the material is beneficial to reducing leakage current, and excellent ferroelectricity and ferromagnetism are shown as shown in a figure 3.
The single-phase multi-iron microwave absorbing material is used as a microwave absorbing agent, and microwave absorbing performance parameters of the single-phase multi-iron microwave absorbing material are obtained by analyzing and measuring the single-phase multi-iron microwave absorbing material by a vector network analyzer and calculating the microwave absorbing performance parameters by a coaxial line theory. The details are as follows:
the NdBi sintered by hot pressing6Ti3(Fe1-xCox)3O21(x is 0.25-0.3) mixing the powder with paraffin (mixing according to the mass ratio of 1: 1), keeping the temperature for half an hour at 80 ℃ to melt the paraffin, uniformly stirring, placing the mixture into a mould, preparing a coaxial ring with the inner diameter of 3mm, the outer diameter of 7mm and the thickness of 3.3mm under the pressure of 2-5MPa, placing the coaxial ring into a coaxial cable clamp for testing, testing by using an Agilent HPE8363B vector network analyzer, testing the range of 2-18GHz, finally obtaining a complex dielectric constant real part, a complex dielectric constant imaginary part, a complex magnetic permeability real part and a complex magnetic permeability imaginary part, finally calculating the reflection loss characteristic of the microwave absorbing material by a classical coaxial cable theory, and fitting different parts in the range of 1-5mmThe reflection loss characteristic of the thickness d of the shaft ring can obtain the relation between different thicknesses d and corresponding reflection losses.
The results show that the NdBi of the invention6Ti3(Fe1-xCox)3O21The (x is 0.25-0.3) material has high microwave absorption performance, and when the thickness of a test coating is about 3mm, the optimal reflection loss value is lower than-30 dB and the bandwidth with the reflection loss lower than-20 dB is higher than 10GHz within the frequency range of 5-8 GHz. And the optimal reflection loss peak position will shift to the low frequency direction as the coating thickness changes, but the reflection loss peak values are all below-30 dB. Compared with the commonly reported carbon nanotube/ferrite composite microwave material (the optimal reflection loss value is about-10 dB to-30 dB, and the frequency bandwidth with the reflection loss lower than-20 dB is about 0-6GHz), the material has high absorption strength (the optimal reflection loss peak is lower than-30 dB), wide absorption frequency bandwidth (the frequency bandwidth with the reflection loss lower than-20 dB is higher than 10GHz), high microwave strength and wide microwave absorption frequency band, and has wide application prospect.
Detailed description of the preferred embodiment 1
NdBi is prepared according to the following steps6Ti3(Fe1-xCox)3O21(x ═ 0.25) single-phase multiferroic microwave absorbing material.
The method comprises the following steps: weighing (0.05/7) mol of sample raw materials according to the stoichiometric ratio of Nd: Bi: Ti: Fe: Co of 1:6:3:2.25:0.75, namely weighing 7.442g of n-butyl titanate (with the purity of 98%), 2.163g of neodymium nitrate hexahydrate (with the purity of 99%), 20.998g of bismuth nitrate pentahydrate (with the purity of 99%), 6.592g of ferric nitrate nonahydrate (with the purity of 98.5%), and 1.575g of cobalt nitrate hexahydrate (with the purity of 98.5%) and dissolving the mixture in a nitric acid solution (20 mL of the nitric acid solution with the concentration of 65-68% is added into a distilled water beaker with the concentration of about 500mL and then 100mL of distilled water is added), 18.616g of ethylenediamine tetraacetic acid (EDTA) with the purity of 98% and 19.123g of citric acid with the purity of 98% are added as complexing agents, and stirring is carried out to obtain a mixed solution.
Step two: adjusting the pH value of the mixed solution to be neutral by ammonia water, and stirring to obtain a clear solution; then placing the mixed solution in a crucible and evaporating to dryness on a heating table until the mixed solution is combusted to obtain a precursor, presintering the obtained powder in a muffle furnace at 750 ℃ for 2h, removing organic matters to obtain powder, and grinding to obtain primary powder of the material;
step three: tabletting the primary powder on a tabletting machine through a die to form; hot-pressing and sintering by using a hot-pressing furnace, wherein the whole process is carried out in a mixed atmosphere of oxygen and argon (Ar/O)21/4, volume ratio), the hot-pressing sintering temperature is 880 ℃, the sintering heat preservation time is 4h, and the pressure of the direct-pressing grinding tool is kept at about 12.56MPa all the time during the sintering heat preservation; cooling to room temperature, taking out the sample to finally obtain the single-phase multiferroic microwave material NdBi6Ti3(Fe0.75Co0.25)3O21。
For the NdBi prepared above6Ti3(Fe0.75Co0.25)3O21The microwave absorption performance of the single-phase multiferroic microwave material was tested as follows.
The NdBi sintered by hot pressing6Ti3(Fe0.75Co0.25)3O21Mixing the powder and paraffin (mixing according to the mass ratio of 1: 1), keeping the temperature for half an hour at 80 ℃ to melt the paraffin, stirring uniformly, placing the mixture into a mold, preparing a coaxial ring with the inner diameter of 3mm, the outer diameter of 7mm and the thickness of 3.3mm under the pressure of 2-5MPa, placing the coaxial ring into a coaxial line clamp for testing, testing by using an Agilent HPE8363B vector network analyzer to test the coaxial line clamp within the test range of 2-18GHz, finally obtaining a real part of a complex dielectric constant, an imaginary part of the complex dielectric constant, a real part of a complex magnetic permeability and an imaginary part of the complex magnetic permeability as shown in figure 4, and finally calculating the reflection loss characteristic of the microwave absorbing material by a classical coaxial line theory as shown in figure 5, and obtaining the mutual relation between different thicknesses and the reflection loss of the microwave absorbing material by fitting different coaxial ring thicknesses within the range of 1-5 mm.
The results show that the single-phase multiferroic microwave absorbing material NdBi6Ti3(Fe0.75Co0.25)3O21Has high microwave absorbing performance. When the thickness of the coating layer is about 3.3mm, the optimal reflection loss can be obtained within the frequency of 6.5GHz, the value is-37.5 dB, and the reflection isThe bandwidth with losses below-20 dB is about 13 GHz. And the optimal reflection loss peak position will shift to the low frequency direction as the coating thickness changes, but the reflection loss peak values are all below-30 dB. Compared with the carbon nano tube/ferrite composite microwave material which is generally reported, the composite microwave material has high microwave intensity and wide microwave absorption frequency band.
Specific example 2
NdBi is prepared according to the following steps6Ti3(Fe1-xCox)3O21(x ═ 0.3) single-phase multiferroic microwave absorbing material.
The method comprises the following steps: weighing (0.05/7) mol of sample raw materials according to the stoichiometric ratio of Nd: Bi: Ti: Fe: Co of 1:6:3:2.1:0.9, namely weighing 7.442g of n-butyl titanate (with the purity of 98%), 2.163g of neodymium nitrate hexahydrate (with the purity of 99%), 20.998g of bismuth nitrate pentahydrate (with the purity of 99%), 6.153g of ferric nitrate nonahydrate (with the purity of 98.5%), 1.899g of cobalt nitrate hexahydrate (with the purity of 98.5%) and dissolving in a nitric acid solution (taking 20mL from a 65-68% nitric acid solution, adding into a distilled water beaker with the concentration of about 500mL, then adding 100mL of distilled water), adding 18.616g of ethylenediamine tetraacetic acid (EDTA) with the purity of 98% and 19.123g of citric acid with the purity of 98% as complexing agents, and stirring to obtain a mixed solution.
Step two: adjusting the pH value of the mixed solution to be neutral by ammonia water, and stirring to obtain a clear solution; then placing the mixed solution in a crucible and evaporating to dryness on a heating table until the mixed solution is combusted to obtain a precursor, presintering the obtained powder in a muffle furnace at 750 ℃ for 2h, removing organic matters to obtain powder, and grinding to obtain primary powder of the material;
step three: tabletting the primary powder on a tabletting machine through a die to form; hot-pressing and sintering by using a hot-pressing furnace, wherein the whole process is carried out in a mixed atmosphere of oxygen and argon (Ar/O)21/4), the hot-pressing sintering temperature is 870 ℃, the sintering heat preservation time is 3h, and the pressure of the hot-pressing sintering temperature on the die is kept at about 12.56MPa all the time; cooling to room temperature, taking out the sample to obtain the single-phase multiferroic microwave material NdBi6Ti3(Fe0.9Co0.3)3O21。
For the abovePreparation of the resulting NdBi6Ti3(Fe0.9Co0.3)3O21The microwave absorption detection of the single-phase multiferroic microwave material is carried out according to the following method.
The NdBi sintered by hot pressing6Ti3(Fe0.9Co0.3)3O21Mixing the powder and paraffin (mixing according to the mass ratio of 1: 1), keeping the temperature for half an hour at 80 ℃ to melt the paraffin, stirring uniformly, placing the mixture into a mold, making a coaxial ring with the inner diameter of 3mm, the outer diameter of 7mm and the thickness of 3.3mm under the pressure of 2-5MPa, placing the coaxial ring into a coaxial line clamp for testing, testing by using an Agilent HPE8363B vector network analyzer, testing the range of 2-18GHz, finally obtaining a complex dielectric constant real part, a complex dielectric constant imaginary part, a complex magnetic permeability real part and a complex magnetic permeability imaginary part, as shown in figure 7, and finally calculating the reflection loss characteristic of the microwave absorbing material by a classical coaxial line theory, as shown in figure 8.
The results show that the single-phase multiferroic microwave absorbing material NdBi6Ti3(Fe0.9Co0.3)3O21Has high microwave absorbing performance. When the thickness of the test coating is about 3.3mm, the optimal reflection loss can be obtained within the frequency of 6.8GHz, the value of the optimal reflection loss is-42.3 dB, and the bandwidth with the reflection loss lower than-20 dB is about 14 GHz. Compared with the carbon nano tube/ferrite composite microwave material which is generally reported, the composite microwave material has high microwave intensity and wide microwave absorption frequency band.
The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (6)

1. A single-phase multiferroic microwave absorbing material, wherein the material has a chemical formula as shown in formula (i): NdBi6Ti3(Fe1-xCox)3O21(i) wherein x is 0.25 to 0.3;
the material structure is a single-phase symbiotic layered perovskite layer structure, and the structure with the single-phase symbiotic layered perovskite layer is a single-phase structure with four perovskite layers and five perovskite layers in a disordered symbiotic state.
2. A method for preparing the single-phase multiferroic microwave absorbing material as defined in claim 1, wherein the method comprises the following steps: the method comprises the following steps:
(1) mixing n-butyl titanate, a bismuth-containing compound, a neodymium-containing compound, an iron-containing compound, a cobalt-containing compound and a complexing agent in a dilute nitric acid solution according to a stoichiometric ratio to obtain a mixed solution;
(2) adjusting the pH value of the mixed solution obtained in the step (1) to be neutral by using ammonia water, stirring to obtain a clear solution, and then evaporating and presintering the clear solution to obtain primary powder;
(3) and (3) tabletting and forming the primary powder obtained in the step (2), and carrying out hot-pressing sintering to obtain the single-phase multiferroic microwave absorbing material.
3. The method of claim 2, wherein: in the step (1), the molar ratio of titanium, bismuth, neodymium, iron and cobalt in the n-butyl titanate, the bismuth-containing compound, the neodymium-containing compound, the iron-containing compound and the cobalt-containing compound is 3:6:1 (3-3x) 3x, and x is 0.25-0.3.
4. The production method according to claim 3, characterized in that: in the step (1), the bismuth-containing compound is bismuth nitrate pentahydrate, the neodymium-containing compound is neodymium nitrate hexahydrate, the iron-containing compound is ferric nitrate nonahydrate, the cobalt-containing compound is cobalt nitrate hexahydrate, and the complexing agent is citric acid and ethylenediamine tetraacetic acid.
5. The method of claim 2, wherein: in the step (2), the pre-sintering temperature is 700-750 ℃, and the pre-sintering time is 2-5 h.
6. The method of claim 2, wherein: in the step (3), the sintering temperature is 850-900 ℃, the sintering time is 3-6h, the sintering atmosphere is a mixed atmosphere formed by oxygen and argon according to the volume ratio of (3-5):1, and the hot-pressing pressure in the sintering process is 12-13 MPa.
CN201810035771.2A 2018-01-15 2018-01-15 Single-phase multi-iron microwave absorbing material and preparation method thereof Active CN108558387B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810035771.2A CN108558387B (en) 2018-01-15 2018-01-15 Single-phase multi-iron microwave absorbing material and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810035771.2A CN108558387B (en) 2018-01-15 2018-01-15 Single-phase multi-iron microwave absorbing material and preparation method thereof

Publications (2)

Publication Number Publication Date
CN108558387A CN108558387A (en) 2018-09-21
CN108558387B true CN108558387B (en) 2020-10-30

Family

ID=63529892

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810035771.2A Active CN108558387B (en) 2018-01-15 2018-01-15 Single-phase multi-iron microwave absorbing material and preparation method thereof

Country Status (1)

Country Link
CN (1) CN108558387B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110922181B (en) * 2019-11-29 2021-09-21 湖南工程学院 Flaky ceramic wave-absorbing material and preparation method thereof
CN110922180B (en) * 2019-11-29 2021-11-09 湖南工程学院 Multi-iron wave-absorbing material and preparation method thereof

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103288437B (en) * 2012-06-21 2015-01-07 中国科学技术大学 Six-layer ferrotitanium yttrium bismuth cobaltate ceramic material with multiferroic performance and preparation method thereof
CN104098143B (en) * 2014-07-30 2015-10-28 中国科学技术大学 Multifunctional single-phase nano material

Also Published As

Publication number Publication date
CN108558387A (en) 2018-09-21

Similar Documents

Publication Publication Date Title
Shahbaz Tehrani et al. Structural, magnetic, and optical properties of zinc-and copper-substituted nickel ferrite nanocrystals
Kumar et al. Effect of La3+ doping on the electric, dielectric and magnetic properties of cobalt ferrite processed by co-precipitation technique
Peng et al. Fe-based soft magnetic composites coated with NiZn ferrite prepared by a co-precipitation method
Amighian et al. Preparation of nano‐sized manganese ferrite (MnFe2O4) via coprecipitation method
Sujatha et al. Effects of heat treatment conditions on the structural and magnetic properties of MgCuZn nano ferrite
Ahmad et al. Effect of sintering temperature on magnetic and electrical properties of nano-sized Co2W hexaferrites
Verma et al. Low temperature processing of NiZn ferrite by citrate precursor method and study of properties
Gabal et al. Cr-substituted Ni–Zn ferrites via oxalate decomposition. Structural, electrical and magnetic properties
Gadkari et al. Synthesis, characterization and magnetic properties of La3+ added Mg–Cd ferrites prepared by oxalate co-precipitation method
Hashim et al. High temperature dielectric studies of indium-substituted NiCuZn nanoferrites
Ghasemi et al. The microstructure and magnetic behavior of spark plasma sintered iron/nickel zinc ferrite nanocomposite synthesized by the complex sol-gel method
Kaur et al. Studies on structural and magnetic properties of ternary cobalt magnesium zinc (CMZ) Co0. 6-xMgxZn0. 4 Fe2O4 (x= 0.0, 0.2, 0.4, 0.6) ferrite nanoparticles
Gabal et al. Structural, magnetic and electrical properties of Ga-substituted NiCuZn nanocrystalline ferrite
Manikandan et al. Influence of sintering temperature on structural, dielectric and magnetic properties of Li substituted CuFe2O4 nanoparticles
Zhang et al. Microstructure characterization and properties of chemically synthesized Co2Z hexaferrite
Mugutkar et al. Ammonia gas sensing and magnetic permeability of enhanced surface area and high porosity lanthanum substituted Co–Zn nano ferrites
CN108558387B (en) Single-phase multi-iron microwave absorbing material and preparation method thereof
Wang et al. Preparation and characterizations of ultrafine hexaganoal ferrite Co2Z powders
Mathur et al. Low temperature synthesis of Mn0. 4Zn0. 6In0. 5Fe1. 5O4 nanoferrite for high-frequency applications
Bachhav et al. Microstructure and magnetic studies of Mg–Ni–Zn–Cu ferrites
Su et al. Effects of ${\hbox {Nb}} _ {2}{\hbox {O}} _ {5} $ on DC-Bias-Superposition Characteristic of the Low-Temperature-Fired NiCuZn Ferrites
Patil et al. Tuning the structural, optical and magnetic properties of NiCuZn (Ni0. 4Cu0. 3Zn0. 3Fe2O4) spinel ferrites by Nb2O5 additive
Verma et al. Low-temperature synthesis of nanocrystalline powders of lithium ferrite by an autocombustion method using citric acid and glycine
Agami et al. Structural, IR, and magnetic studies of annealed Li-ferrite nanoparticles
Ahmad et al. Synthesis and electrical behavior of Ni-Ti substituted Y-type hexaferrites for high frequency application

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
GR01 Patent grant
GR01 Patent grant