Carbonyl iron powder/lanthanum strontium manganate composite and preparation method thereof

A carbonyl iron powder, composite material technology, applied in chemical instruments and methods, other chemical processes, radiation-absorbing coatings, etc. Thin, lightweight and other issues, to achieve the effect of good absorbing performance

Inactive Publication Date: 2011-04-20
HEFEI INSTITUTES OF PHYSICAL SCIENCE - CHINESE ACAD OF SCI
View PDF5 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, these absorbing materials based on chemical methods and their preparation processes have shortcomings. First, the thickness of the absorbing materials in the microwave band, such as the X-band, needs to be greater than 1 mm, which is difficult to meet the requirements of practical applications. In the middle, the requirements for the characteristics of broadba

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Carbonyl iron powder/lanthanum strontium manganate composite and preparation method thereof
  • Carbonyl iron powder/lanthanum strontium manganate composite and preparation method thereof
  • Carbonyl iron powder/lanthanum strontium manganate composite and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] The concrete steps of preparation are:

[0021] Step 1, first lanthanum oxide, strontium carbonate and manganese carbonate according to La 1-x Sr x MnO 3 The stoichiometric ratio is added into the aqueous solution of nitric acid under stirring until it is completely dissolved to obtain a mixed solution; wherein, La 1-x Sr x MnO 3x in the powder is 0.25, the volume ratio of nitric acid:water in the nitric acid aqueous solution is 1:50, and the water is deionized water. Add citric acid to the mixed solution placed at 60° C. to obtain an intermediate solution, wherein the molar ratio between citric acid and manganese carbonate in the mixed solution is 2:1. Next, first add ammonia water dropwise to the intermediate liquid until its pH value is 6, and place it at 60°C to continue stirring until a gel is formed; then place the gel at 100°C to keep warm until the gel is dried, Obtain gel dry powder. Afterwards, the dry gel powder was pre-calcined at 200°C for 4 hours, a...

Embodiment 2

[0024] The concrete steps of preparation are:

[0025] Step 1, first lanthanum oxide, strontium carbonate and manganese carbonate according to La 1-x Sr x MnO 3 The stoichiometric ratio is added into the aqueous solution of nitric acid under stirring until it is completely dissolved to obtain a mixed solution; wherein, La 1-x Sr x MnO 3 x in the powder is 0.33, the volume ratio of nitric acid:water in the nitric acid aqueous solution is 1:63, and the water is distilled water. Add citric acid to the mixed solution placed at 69° C. to obtain an intermediate solution, wherein the molar ratio between citric acid and manganese carbonate in the mixed solution is 3.5:1. Next, add ammonia water dropwise to the intermediate solution until its pH value is 6.3, and place it at 69°C to continue stirring until a gel is formed; then place the gel at 115°C to keep warm until the gel is dried, Obtain gel dry powder. Afterwards, the dry gel powder was pre-calcined at 235°C for 3.5 hours...

Embodiment 3

[0028] The concrete steps of preparation are:

[0029] Step 1, first lanthanum oxide, strontium carbonate and manganese carbonate according to La 1-x Sr x MnO 3 The stoichiometric ratio is added into the aqueous solution of nitric acid under stirring until it is completely dissolved to obtain a mixed solution; wherein, La 1-x Sr x MnO 3 x in the powder is 0.4, the volume ratio of nitric acid:water in the nitric acid aqueous solution is 1:75, and the water is deionized water. Add citric acid to the mixed solution placed at 78° C. to obtain an intermediate solution, wherein the molar ratio between citric acid and manganese carbonate in the mixed solution is 5:1. Next, add ammonia water dropwise to the intermediate liquid until its pH value is 6.5, and place it at 78°C to continue stirring until a gel is formed; then place the gel at 130°C to keep warm until the gel is dried, Obtain gel dry powder. Afterwards, the dry gel powder was pre-calcined at 275°C for 3 hours, and t...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a carbonyl iron powder/lanthanum strontium manganate composite and a preparation method thereof. The composite is formed by mixing the following components in percentage by weight: 7.25 to 98.75 percent of carbonyl iron powder and 1.25 to 22.75 percent of La1-xSrxMnO3 powder, wherein x in the La1-xSrxMnO3 powder is between 0.25 and 0.55. The method comprises the following steps of: adding lanthanum oxide, strontium carbonate and manganese carbonate into aqueous solution of hydrogen nitrate according to a stoichiometric ratio of La1-xSrxMnO3 to obtain mixed liquor, and adding citric acid into the mixed liquor at the temperature of between 60 and 95 DEG C to obtain intermediate liquor; adding ammonia water into the intermediate liquor dropwise until the pH value is between 6 and 7, stirring at the temperature of between 60 and 95 DEG C to form gel, and performing heat preservation on the gel at the temperature of between 100 and 150 DEG C to obtain gel dry powder; presintering the gel dry powder at the temperature of between 200 and 350 DEG C for 2 to 4 hours, and grinding to obtain powder; performing heat treatment on the powder at the temperature of between650 and 800 DEG C for 2 to 8 hours to obtain the La1-xSrxMnO3 powder; and mixing the carbonyl iron powder and the La1-xSrxMnO3 powder according to the required ratio to obtain the composite. The carbonyl iron powder/lanthanum strontium manganate composite can absorb electromagnetic waves uniformly and effectively within the frequency range of between 8 and 12 GHz under the condition that the thickness is less than 1 millimeter.

Description

technical field [0001] The invention relates to a composite material and a preparation method, in particular to a carbonyl iron powder / strontium lanthanum manganate composite material and a preparation method thereof. Background technique [0002] In recent years, the increasingly serious electromagnetic wave pollution has made the study of absorbing materials with broadband, strong absorption, light weight and other characteristics attract extensive attention. In the design and preparation process of absorbing materials, especially when the frequency and thickness are fixed, it is required that the absorbing materials must have a large magnetic permeability and permittivity at the same time, and a good relationship between the two must be achieved. match. Magnetic metal particles, such as nickel, cobalt, and carbonyl iron particles, have high saturation magnetization and high relative permeability in the microwave band, so they can be used as microwave absorbers in the mic...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C09K3/00C09D5/32H05K9/00
Inventor 程玉兰戴建明刘强春吴大俊孙玉平
Owner HEFEI INSTITUTES OF PHYSICAL SCIENCE - CHINESE ACAD OF SCI
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap