Absorbing properties and structural design of microwave absorbers based on carbonyl iron and barium ferrite

Abstract Carbonyl iron and barium ferrite powder (BaZn1.5Co0.5Fe16O27) were prepared in this work. The complex permittivity and permeability spectra for rubber radar absorbing materials employing carbonyl iron and barium ferrite powders were measured. A database describing the frequency dependence of the permittivities and permeabilities of the carbonyl iron and barium ferrite microwave absorbers with various powder percentage compositions in 2–18 GHz was created. Based on the database, the single-layer and double-layer absorbers were designed and prepared, and their microwave absorption properties were investigated. The results indicate that the carbonyl iron powder prepared via thermal decomposition of iron pentacarbonyl is single cubic iron and of spherical shape. The barium ferrite powder is single W-type ferrite and a hexagonal flake. The absorption band of the double-layer microwave absorber is obviously more than that of the single-layer absorber. The double-layer microwave absorbers with reflection loss

[1]  Zhaobo Wang,et al.  Ni-Fe-Co-P coatings on coiled carbon nanofibers , 2005 .

[2]  H. Okino,et al.  Dielectric and Magnetic Properties of a Titanium Oxide and Carbonyl Iron Composite Material and Application as a Microwave Absorber , 2004 .

[3]  H. Okino,et al.  Double-layer type microwave absorber made of magnetic-dielectric composite material , 2002 .

[4]  P. A. Joy,et al.  Evaluation of the Magnetic and Mechanical Properties of Rubber Ferrite Composites Containing Strontium Ferrite , 2004 .

[5]  X. Yao,et al.  Preparation of magnetic cobalt fibres and their microwave properties , 2000 .

[6]  A. M. Nicolson,et al.  Measurement of the Intrinsic Properties of Materials by Time-Domain Techniques , 1970 .

[7]  Tobias Lindström,et al.  Magnesium diboride nanobridges fabricated by electron-beam lithography , 2005 .

[8]  J. Akedo,et al.  Magnetic properties and microwave characteristics of Ni-Zn-Cu ferrite film fabricated by aerosol deposition method , 2005 .

[9]  Mao-Sheng Cao,et al.  Computation design and performance prediction towards a multi-layer microwave absorber , 2002 .

[10]  J. Xiong,et al.  Microwave-absorbing properties of de-aggregated flake-shaped carbonyl-iron particle composites at 2-18 GHz , 2006 .

[11]  Muyu Zhao,et al.  Microwave absorptive behavior of ZnCo-substituted W-type Ba hexaferrite nanocrystalline composite material , 2000 .

[12]  Baoshan Zhang,et al.  Microwave absorption studies of W-hexaferrite prepared by co-precipitation/mechanical milling , 2003 .

[13]  Myung-Jun Park,et al.  Wide bandwidth pyramidal absorbers of granular ferrite and carbonyl iron powders , 2000 .

[14]  P. B. Jana,et al.  Effects of sample thickness and fiber aspect ratio on EMI shielding effectiveness of carbon fiber filled polychloroprene composites in the X-band frequency range , 1992 .

[15]  R. Gong,et al.  Optimization of two-layer electromagnetic wave absorbers composed of magnetic and dielectric materials in gigahertz frequency band , 2005 .

[16]  E. J. Vanzura,et al.  Improved technique for determining complex permittivity with the transmission/reflection method , 1990 .