Magnetic materials based on manganese–zinc ferrite with surface-organized polyaniline coating

Polyaniline containing W-type hexaferrite composites for microwave absorption in high-frequency applications

“…whereas the imaginary part (μ″) of the permeability remains constant with a little fluctuation in the measured frequency range. The increase results of the μ′ of the composites with the increasing PANI ratio were consistent with that of polymer-ferrite composites reported in the papers [25,26], although some of the opposite results were reported in the previous papers [27,28]. With the increasing frequency, the magnetic dipole tries to rotate with the frequency, but at a higher frequency due to the strong anisotropy, the induced magnetization (B) lags behind the applied field (H), which results in magnetic losses.…”

Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials

“…Considering applications of these materials in military area it can say that the energy scattered from a target (eco-radar), that would be used for its detection by radar, is attenuated and the object coated with RAM becomes stealth or, as reported in the literature, "invisible" to radar. In civilian applications, the RAM use brings benefits in different areas, such as in telecommunication area coating cell phones and radio transmitting antennas; in medical sector coating, for example, electronic pacemakers and equipment; in anechoic chambers used for research and industrial purposes; in home appliances in general, in electromagnetic shielding and control of interference, among other applications [8][9][10] . Usually, microwave absorbing coatings are composite materials that may present itself in various forms such as plates of elastomeric polymers based on polyisoprene and polychloroprene; flexible blankets of different types of rubbers and paints based on epoxy, phenolic and polyurethane resins 3,11,12 .…”

Synthesis, characterization and surface properties of Fe2O3 decorated ferromagnetic polypyrrole nanocomposites

“…Therefore, conjugated polymers combined with magnetic nanoparticles to form ferromagnetic nanocomposites provide an exciting system to investigate the possibility of exhibiting novel functionality to provide the better microwave absorption properties. Number of articles reported the synthesis and electrical properties of polymer nanocomposites of polypyrrole and polyaniline incorporating ferrite particles in the polymer matrix [20][21][22][23][24][25]. Bidan et al has reported the electrochemical method to prepare polypyrrole composite exhibiting magnetic and conducting properties [26].…”