Gigahertz range electromagnetic wave absorbers made of amorphous-carbon-based magnetic nanocomposites
- 1 September 2005
- journal article
- research article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 98 (5), 054305
- https://doi.org/10.1063/1.2009082
Abstract
Nanocomposite magnetic materials α-Fe∕C(a), Fe2B∕C(a), and Fe1.4Co0.6B∕C(a) were prepared by mechanically grinding α-Fe, Fe2B, or Fe1.4Co0.6B with amorphous carbon [C(a)] powders. Complex permittivity, permeability, and electromagnetic wave absorption properties of resin compacts containing 40-vol% composite powders of α-Fe∕C(a), Fe2B∕C(a), and Fe1.4Co0.6B∕C(a) were characterized according to a conventional reflection/transmission technique. The real part (εr′) and imaginary part (εr″) of the relative permittivity are low and almost independent of frequency between 0.05 and 40GHz. The Imaginary part (μr″) of the relative permeability exhibited wide peaks in the 1–9-GHz range for α-Fe∕C(a), in the 2–18-GHz range for Fe2B∕C(a), and in the 18–40-GHz range for Fe1.4Co0.6B∕C(a) owing to their different magnetocrystalline anisotropy field (HA) values. Consequently, the resin compacts of 40-vol% α-Fe∕C(a), Fe2B∕C(a), and Fe1.4Co0.6B∕C(a) powders provided good electromagnetic (em) wave absorption performances (reflection loss<−20dB) in ranges of 4.3–8.2GHz (G band), 7.5–16.0GHz (X band), and 26.5–40GHz (Q band) over absorber thicknesses of 1.8–3.3, 1.2–2.2, and 0.63–0.82mm, respectively. Our experimental results demonstrate that the amorphous-carbon-based magnetic nanocomposites are promising for the application to produce thin and light EM wave absorbers.Keywords
This publication has 49 references indexed in Scilit:
- Electrical and Physical Properties of Carbonized CharcoalsIndustrial & Engineering Chemistry Research, 2003
- Z type Ba hexagonal ferrites with tailored microwave propertiesJournal of Applied Physics, 2002
- Standing spin waves in granular Fe–SiO2 thin filmsJournal of Applied Physics, 2000
- Nanostructured Fe networks studied by ferromagnetic resonanceIEEE Transactions on Magnetics, 2000
- Effect of milling temperature and additive elements on an Fe–C system alloy prepared by mechanical alloyingJournal of the American Academy of Dermatology, 1999
- Properties of pulsed laser deposited scandium-doped barium hexaferrite filmsJournal of Applied Physics, 1999
- Magnetic and structural properties of laser deposited lithium ferrite filmsIEEE Transactions on Magnetics, 1994
- Thin-layer electromagnetic absorber designIEEE Transactions on Magnetics, 1989
- Application of Ferrite to Electromagnetic Wave Absorber and its CharacteristicsIEEE Transactions on Microwave Theory and Techniques, 1971
- Dispersion and absorption in magnetic ferrites at frequencies above one Mc/sPhysica, 1948