A Method of Using Dielectric/Ferromagnetic Composite Materials to Absorb Microwaves

A composite material and dielectric technology, applied in radiation-absorbing coatings, chemical instruments and methods, and other chemical processes, can solve problems such as narrow absorption frequency bands, and achieve the effects of wide frequency bands, broad application prospects, and low density

Active Publication Date: 2016-04-27
INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method for absorbing microwaves using a dielectric / ferromagnetic composite material to solve the problem of a single type of microwave absorbing material with a narrow absorption frequency band

Method used

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  • A Method of Using Dielectric/Ferromagnetic Composite Materials to Absorb Microwaves
  • A Method of Using Dielectric/Ferromagnetic Composite Materials to Absorb Microwaves
  • A Method of Using Dielectric/Ferromagnetic Composite Materials to Absorb Microwaves

Examples

Experimental program
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Effect test

Embodiment 1

[0023] The described dielectric / ferromagnetic composite microwave absorbing material is prepared in the following steps:

[0024] (1) Using the sol-gel method, using ethylene glycol methyl ether and monoethanolamine as solvents, lanthanum nitrate and nickel acetate as starting materials, annealing at 700 °C for 1.5 hours in air to obtain loose and porous nickel acid with oxygen vacancies Lanthanum powder (such as figure 1 shown);

[0025] (2) Carbon-coated iron-cobalt nanocapsules were prepared by DC plasma arc method;

[0026] (3) 50wt% lanthanum nickelate (LaNiO 3 ) powder and 50wt% iron-cobalt-cobalt-carbon (FeCo / C) nanocapsules were dispersed in ethanol, and then the two suspensions were ultrasonically mixed, mixed uniformly and then dried to obtain LaNiO 3 -FeCo / C (50 / 50) composite.

[0027] (4) Preparation of absorbing samples:

[0028] 0.4g LaNiO prepared in step (3) 3 -FeCo / C(50 / 50) composite mixed with 0.6g paraffin (LaNiO 3 -FeCo / C (50 / 50) composite material h...

Embodiment 2

[0030] The described dielectric / ferromagnetic composite microwave absorbing material is prepared in the following steps:

[0031] (1) Using the sol-gel method, using ethylene glycol methyl ether and monoethanolamine as solvents, lanthanum nitrate and nickel acetate as starting materials, annealing at 700 °C for 1.5 hours in air to obtain loose and porous nickel acid with oxygen vacancies Lanthanum powder (such as figure 1 shown);

[0032] (2) Carbon-coated iron-cobalt nanocapsules were prepared by DC plasma arc method;

[0033] (3) 80wt% lanthanum nickelate (LaNiO 3 ) powder and 20wt% iron-cobalt-cobalt-carbon (FeCo / C) nanocapsules were dispersed in ethanol, then the two suspensions were ultrasonically mixed, mixed uniformly and then dried to obtain LaNiO 3 -FeCo / C (80 / 20) composite.

[0034] (4) Preparation of absorbing samples:

[0035] 0.4g LaNiO prepared in step (3) 3 -FeCo / C(80 / 20) composite mixed with 0.6g paraffin (LaNiO 3 -FeCo / C (80 / 20) composite material has a...

Embodiment 3

[0037] The difference from Example 2 is: lanthanum nickelate (LaNiO 3 ) powder and carbon-coated iron cobalt (FeCo / C) nanocapsules with a mass ratio of 20:80, and the obtained composite material is LaNiO 3 -FeCo / C(20 / 80), the reflection loss of the absorbing sample made of this composite material has absorption below -10dB at different frequencies (see Image 6 ).

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Abstract

The invention aims to provide a method for absorbing microwaves by adopting a dielectric / ferromagnetic composite material, and is used for solving the deficiency of narrow absorbing frequency band of a single-species wave absorbing material. The composite material takes a lanthanum nickelate powder as a dielectric component, and takes carbon-coated iron cobalt as a ferromagnetic component. The composite material has the advantages of small density and wide frequency band width, and has broad application prospects in electromagnetic shielding, photoelectric materials, electrorheological fluids, functional coatings and the like.

Description

technical field [0001] The invention belongs to the field of electromagnetic wave absorption, and particularly provides a method for absorbing microwaves by using a dielectric / ferromagnetic composite material. Background technique [0002] Microwave absorbing materials refer to materials that can absorb microwaves and convert microwaves into thermal energy. Such materials have been widely used in military and civilian fields such as electromagnetic pollution shielding and stealth technology. Microwave absorbing materials can be divided into dielectric loss type materials and magnetic loss type materials according to the loss mechanism. The dielectric loss type microwave absorbing materials are represented by carbon black and barium titanate, and the magnetic loss type materials include ferrite and magnetic metal particles. . Absorbers with a single loss type often have the disadvantage of narrow absorption band, while composite materials with different loss mechanisms can a...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09K3/00C09D5/32C09D7/12
Inventor 姜菁菁李达耿殿禹李少杰刘伟张志东
Owner INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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