Microwave absorption properties of the core/shell-type iron and nickel nanoparticles

Abstract Iron (Fe) and nickel (Ni) nanoparticles were prepared by the DC arc-discharge method in a mixture of hydrogen and argon gases, using bulk metals as the raw materials. The microstructure of core/shell (metal/metal oxide) in nanoparticle formed after in situ passivation process. The complex electromagnetic parameters (permittivity e r = e r ′ + i e r ″ and permeability μ r = μ r ′ + i μ r ″ ) of the paraffin-mixed nanocomposite samples (paraffin:nanoparticles=1:1 in mass ratio) were measured in the frequency range of 2–18 GHz. The polarization mechanisms of the space charge and dipole coexist in both the Fe and Ni nanoparticles. The orientational polarization is a particular polarization for Fe nanoparticles and brings a relatively higher dielectric loss. Natural resonance is the main reason for magnetic loss and the corresponding frequencies are 11.6 and 5.2 GHz for the Fe and Ni nanoparticles, respectively. The paraffin composite with Fe nanoparticles provided excellent microwave absorption properties (reflection loss

[1]  Masahiro Itoh,et al.  Magnetic and electromagnetic wave absorption properties of α-Fe∕Z-type Ba-ferrite nanocomposites , 2006 .

[2]  Z. Lü,et al.  A study of (Ba0.5Sr0.5)1 − xSmxCo0.8Fe0.2O3 − δ as a cathode material for IT-SOFCs , 2006 .

[3]  T. Xiao,et al.  Microwave magnetic properties of Co50/(SiO2)50 nanoparticles , 2002 .

[4]  X. Batlle,et al.  Finite-size effects in fine particles: magnetic and transport properties , 2002 .

[5]  Xiaoyun Li,et al.  Electromagnetic and absorption properties of carbonyl iron/rubber radar absorbing materials , 2006 .

[6]  Joonmo Ahn,et al.  Magnetic and microwave absorbing properties of Co–Fe thin films plated on hollow ceramic microspheres of low density , 2004 .

[7]  Olivier Acher,et al.  Effective medium at finite frequency: Theory and experiment , 1993 .

[8]  L. Thomas,et al.  Surface effects on the magnetic properties of ultrafine cobalt particles , 1998 .

[9]  V. Bregar,et al.  Advantages of ferromagnetic nanoparticle composites in microwave absorbers , 2004, IEEE Transactions on Magnetics.

[10]  Yang Liu,et al.  Microwave absorption properties of the carbon-coated nickel nanocapsules , 2006 .

[11]  X. Dong,et al.  Structural and magnetic characterization of Fe nanoparticles synthesized by chemical vapor condensation process , 2002 .

[12]  Sung-soo Kim,et al.  Magnetic, dielectric, and microwave absorbing properties of iron particles dispersed in rubber matrix in gigahertz frequencies , 2005 .

[13]  S. Gangopadhyay,et al.  Permittivity enhancement of aluminum oxide thin films with the addition of silver nanoparticles , 2006 .

[14]  J. L. Snoek.  Dispersion and absorption in magnetic ferrites at frequencies above one Mc/s , 1948 .

[15]  Hiroyasu Ota,et al.  GHz microwave absorption of a fine α-Fe structure produced by the disproportionation of Sm2Fe17 in hydrogen , 2002 .

[16]  Yukio Hishikawa,et al.  Electromagnetic wave absorption property of carbon microcoils in 12–110 GHz region , 2003 .

[17]  A. Hippel,et al.  DIELECTRIC SPECTROSCOPY OF FERROMAGNETIC SEMICONDUCTORS , 1957 .

[18]  Electrical resistivity and magnetoresistance in monodispersed oxide-coated Fe cluster assemblies , 2004 .

[19]  O. Acher,et al.  Preparation and microwave characterization of spherical and monodisperse CoNi particles , 1995 .

[20]  X. Zhao,et al.  The preparation and characterization of ultrafine Fe–Ni particles , 1999 .

[21]  X. Dong,et al.  Surface characterizations of ultrafine Ni particles , 1998 .

[22]  S. Linderoth,et al.  Surface effects in metallic iron nanoparticles. , 1994, Physical review letters.

[23]  C. Kittel.  On the Theory of Ferromagnetic Resonance Absorption , 1948 .

[24]  D. Peng,et al.  Structural and magnetic characteristics of monodispersed Fe and oxide-coated Fe cluster assemblies , 2002 .

[25]  B. Gu,et al.  Preparation and properties of a novel iron-coated carbon fiber , 2003 .

[26]  Masahiro Itoh,et al.  Electromagnetic wave absorption properties of α-Fe/Fe3B/Y2O3 nanocomposites in gigahertz range , 2003 .

[27]  Sahrim Ahmad,et al.  Electromagnetic and absorption properties of some microwave absorbers , 2002 .

[28]  Jiurong Liu,et al.  Gigahertz range electromagnetic wave absorbers made of amorphous-carbon-based magnetic nanocomposites , 2005 .