TY - JOUR
T1 - Gigahertz range electromagnetic wave absorbers made of amorphous-carbon-based magnetic nanocomposites
AU - Liu, Jiu Rong
AU - Itoh, Masahiro
AU - Horikawa, Takashi
AU - MacHida, Ken Ichi
AU - Sugimoto, Satoshi
AU - Maeda, Toru
N1 - Funding Information:
This work was supported by Grant-in-Aid for Scientific Research No. 15205025 from the Ministry of Education, Science, Sports, and Culture of Japan, and Industrial Technology Research Grant Program in 2003 from New Energy and Industrial Technology Development Organization (NEDO) of Japan.
PY - 2005/9/1
Y1 - 2005/9/1
N2 - Nanocomposite magnetic materials α-FeC (a), Fe2 BC (a), and Fe1.4 Co0.6 BC (a) were prepared by mechanically grinding α-Fe, Fe2 B, or Fe1.4 Co0.6 B with amorphous carbon [C (a)] powders. Complex permittivity, permeability, and electromagnetic wave absorption properties of resin compacts containing 40-vol % composite powders of α-FeC (a), Fe2 BC (a), and Fe1.4 Co0.6 BC (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 40 GHz. The Imaginary part (μr″) of the relative permeability exhibited wide peaks in the 1-9-GHz range for α-FeC (a), in the 2-18-GHz range for Fe2 BC (a), and in the 18-40-GHz range for Fe1.4 Co0.6 BC (a) owing to their different magnetocrystalline anisotropy field (HA) values. Consequently, the resin compacts of 40-vol % α-FeC (a), Fe2 BC (a), and Fe1.4 Co0.6 BC (a) powders provided good electromagnetic (em) wave absorption performances (reflection loss<-20 dB) in ranges of 4.3-8.2 GHz (G band), 7.5-16.0 GHz (X band), and 26.5-40 GHz (Q band) over absorber thicknesses of 1.8-3.3, 1.2-2.2, and 0.63-0.82 mm, 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.
AB - Nanocomposite magnetic materials α-FeC (a), Fe2 BC (a), and Fe1.4 Co0.6 BC (a) were prepared by mechanically grinding α-Fe, Fe2 B, or Fe1.4 Co0.6 B with amorphous carbon [C (a)] powders. Complex permittivity, permeability, and electromagnetic wave absorption properties of resin compacts containing 40-vol % composite powders of α-FeC (a), Fe2 BC (a), and Fe1.4 Co0.6 BC (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 40 GHz. The Imaginary part (μr″) of the relative permeability exhibited wide peaks in the 1-9-GHz range for α-FeC (a), in the 2-18-GHz range for Fe2 BC (a), and in the 18-40-GHz range for Fe1.4 Co0.6 BC (a) owing to their different magnetocrystalline anisotropy field (HA) values. Consequently, the resin compacts of 40-vol % α-FeC (a), Fe2 BC (a), and Fe1.4 Co0.6 BC (a) powders provided good electromagnetic (em) wave absorption performances (reflection loss<-20 dB) in ranges of 4.3-8.2 GHz (G band), 7.5-16.0 GHz (X band), and 26.5-40 GHz (Q band) over absorber thicknesses of 1.8-3.3, 1.2-2.2, and 0.63-0.82 mm, 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.
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U2 - 10.1063/1.2009082
DO - 10.1063/1.2009082
M3 - Article
AN - SCOPUS:25144472779
SN - 0021-8979
VL - 98
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 5
M1 - 054305
ER -