Study On The Modified Preparation And Microwave Absorbing Properties Of Magnetic Composite

Magnetic materials such as carbonyl iron and iron tetroxide are widely used in the field of absorbing materials because of their low cost,good absorbing effect and good permeability.However,magnetic materials as absorbing materials also have obvious disadvantages compared with other absorbing materials.Magnetic materials are similar to iron products in that they are not resistant to oxidation,have high density and tend to aggregate.With the development of society and the development of science and technology,the requirements of science and technology products on materials are getting higher and higher.A single magnetic material can no longer meet the requirements directly as a wave absorbing material.The ideal wave absorbing material should meet the requirements of thin,low,wide and anti-oxidation.Magnetic metal absorbing material has a high conductivity(conductor),the use of non-magnetic particles to cover the magnetic metal material can effectively reduce its dielectric constant,conducive to impedance matching,improve the low-frequency absorbing performance of the material.In this paper,aiming at the above disadvantages of magnetic materials,the magnetic materials carbonyl iron and iron tetroxide were coated by sol-gel method to prepare the magnetic dielectric composite materials with light weight and high temperature oxidation resistance,and the surface morphology,phase composition and electromagnetic properties were characterized,and the electromagnetic parameters and wave absorbency were studied.Taking carbonyl iron as the core body,barium titanate(Ba Ti O3)was coated on the surface of carbonyl iron by sol-gel method,forming CIP/Ba Ti O3 as the absorbing material of core-shell structure.The composite wave absorbing material Fe3O4/Ti O2 with good absorbing properties was prepared by coating titanium dioxide(Ti O2)on the surface of ferric oxide by sol-gel method with ferric oxide as the core.The magnetic dielectric composite was measured by vector network analyzer and the reflection loss was calculated.The results showed that the permittivity of magnetic materials such as carbonyl iron and iron tetroxide was increased due to the coating of barium titanate and titanium dioxide,and the impedance matching reached the ideal requirement.It can better improve the defects of the magnetic material such as oxidation resistance,high density and poor dielectric properties,and can improve the wave absorbing performance of the magnetic material.