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1

Fabrication and characterization of iron coated carbon nanotubes/polymer composite for microwave absorption

Kaur Gurjit, Deep Aul Gagan

Composites Theory and Practice

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2020

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R. 20, nr 3-4

111--117

EN

Electrical characteristics of iron coated multi-walled carbon nanotubes (MWNTs) along with ferromagnetic properties are very interesting nanomaterial for microwave absorption. In this research work, surface morphology, compositions and microwave absorption properties of polymer containing iron coated MWNTs have been investigated. Iron coated multi-walled carbon nanotubes composite were prepared by two simple steps method. In addition, microstructure and microwave absorption properties under frequency range 8÷13 GHz by means of FESEM, EDX &Vector network analyzer had shown. The maximum reflection loss is observed for Fe-coated MWNTs/polymer sample B is –20.86 dB and –18.13 dB at frequency 8.1 and 10.75 GHz respectively. And the maximum bandwidth window is available for sample C is 3.25 GHz from frequency 8.45 to 11.7 GHz with 3 mm thickness, which can be attributed to synergistic effect of improved impedance matching characteristic and superior microwave attenuation characteristic of the absorber. The reflection properties of the material enhanced with variations in the wt.% of Fe-coated MWNTs and polymer. In this research paper, Fe-coated MWNTs are analyzed as promising microwave absorbing material and combined utilization of dielectric loss and magnetic loss absorbent design shows great design flexibility and diversity in the frequency range 8÷13 GHz.

2

Stealth technology. Yesterday, today and tomorrow

Skalski P., Krupski J.

Logistyka

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2014

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nr 6

9554--9561

EN

Stealth technology continuous to grow in significance with the development of radars and an ever changing battlefield. Nowadays, not only aircraft, but other types of units like helicopters, ships, land vehicles, submarines and missiles are constructed with low-observable technology. This paper covers the most important methods of making objects less visible and less-detectable. The paper will give a short description of radar, infrared, visual, sonar (acoustic), and plasma. Radar absorbing materials, the most researched element of stealth technology, still present enormous potential. Authors of the paper presented a magnetorheological elastomer as a future material in the stealth technology.

PL

Znaczenie technologii stealth ciągle rośnie wraz z rozwojem radarów i zmieniającym się polem bitwy. W dzisiejszych czasach nie tylko samoloty, ale inne jednostki takie jak: śmigłowce, statki, pojazdy lądowe, łodzie podwodne i rakiety są zbudowane z myślą o niskie wykrywalności. Praca ta obejmuje najważniejsze sposoby wytwarzania obiektów mało wykrywalnych. W skrócie przedstawiono opis radaru, podczerwieni, techniki wizualnej, akustycznej (sonar) i plazmy. Materiały pochłaniające fale radarowe, wymagają ciągłych badań. Autorzy pracy przedstawiają elastomer magnetoreologiczny jako materiał w przyszłościowym zastosowaniu w technologii stealth.

3

Synthesis and characterization of nanocrystalline Ba3Co0.9Cu1.1Fe24O41 powder and its application in the reduction of radar cross-section

Da Rocha Caffarena V., Ogasawara T., Pinho M. S., Leixas Capitaneo J. L.

Materials Science Poland

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2007

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Vol. 25, No. 3

875--884

EN

There has been a growing and widespread interest in the development of radar absorbing materials (RAM). Z-type hexaferrite is one of the most complex compounds in the family of hexaferrites that may be used in many applications. In this work, the citrate sol-gel process under an inert atmosphere was used to obtain the nanocrystalline Ba3Co0.9Cu1.1Fe24O41 powder to be used as RAM. Cu2+ ions were incorporated into the structure of Ba3Co2Fe24O41 and, consequently, low temperature sintering and good magnetic properties were achieved. Composites of Ba3Co2Fe24O41 with polychloroprene (CR) were obtained for microwave absorption measurements by the transmission/reflection method, using a waveguide medium for the S- band and X-Ku bands. The 80:20 nanocomposite of Ba3Co0.9Cu1.1Fe24O41:CR with 3.0 mm thickness exhibited the best performance as a RAM for the X-band, with 99.50% microwave absorption at 9.5 GHz.