The superior electromagnetic properties of carbonyl-iron/Fe91.2Si3.1P2.9Sb2.8 composites powder and impedance match mechanism

Fabrication and electromagnetic properties of novel FeNi alloy-coated flake graphite prepared by electroless plating

“…The dielectric loss and magnetic loss are complementary and a good electromagnetic impedance matching is set up in the range of 2e18 GHz. In order to further prove that, the coefficient of electromagnetic matching d(d ¼ (m 00 ε 0 )/(m 0 ε 00 )) [4] has been used as the criterion of electromagnetic matching. The electromagnetic matching properties are much better with the d values closing to 1.…”

“…It can be seen that the d values are mostly close to 1. Compared with most magnetic materials with the d values nearly achieving 10 [4,9], the FeNi-FG/paraffin composite exhibit better electromagnetic matching between the dielectric loss and magnetic loss. Thus, the FeNi-FG can be applied as an ideal absorbent to reach good absorption properties in EMA materials.…”

“…Generally, besides high electromagnetic attenuation, an excellent absorbent should also ensure good impedance matching which is crucial for obtaining high microwave absorption properties [3]. The unitary absorbent is difficult to realize good impedance matching for the reason that most microwave absorbents (such as magnetic materials) have higher permittivity than permeability [4]. Recently, many researchers fabricated the wrapped absorbents composited with magnetic materials and carbon materials to enhance the impedance matching of absorbents, such as CF@carbonyl iron [5], C@FeNi 3 [6], Co 3 Fe 7 @C [7], Fe 3 O 4 @C [8].…”

A carbon fiber based three-phase heterostructure composite CF/Co0.2Fe2.8O4/PANI as an efficient electromagnetic wave absorber in the Ku band

“…For comparison, the simulated reflection loss-frequency (RL-F) curves of CF/Co 0.2 Fe 2.8 O 4 are illustrated in Fig. 4 The EM matching performs much better with δ value close to one. For CF/Co 0.2 Fe 2.8 O 4 , with the thickness 4.0-5.5 mm, the RL value below -10 dB can be obtained in the EM frequency range 11-18 GHz.…”

Investigation of the Absorption Properties of the Alloys Fe-Ni and Fe-Ni-Cr Prepared by Mechanical Alloying

“…Wang et al 16 placed heavy emphasis on aspect ratio, electromagnetic properties (l r ¼ l 0 r þ il 00 r ; e r ¼ e 0 r þ ie 00 r ), and RL of Fe-Cr-Si-Al alloy, and reported that aspect ratio was crucially important for increasing reflection loss. Zhonglun et al 17 studied the microwave-absorption properties of iron carbonyl-Fe 91.2 Si 3.1 P 2.9 Sb 2.8 composites, and were the first to introduce the quantitative coefficient of electromagnetic matching to explain microwave absorption. Luo et al 18 13,19 focused on the effect of Cr content on the structure and magnetic properties of Fe-Si-Al-Cr and Fe 1ÀxÀy Ni x Cr y (x = 20, y = 10% by wt), and studied dynamic permeability and permittivity and the static magnetic properties (M S and H C ) of the magnetic materials obtained; no microwave-absorption properties were reported.…”