• Title/Summary/Keyword: NiFe

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A Study on $[Ni_x-Mg_{0.1}-Zn_{(1-x-0.1)}{\cdot}Fe_2O_4]$-Rubber Composite for Electromagnetic Wave Absorber (전파흡수체용 $[Ni_x-Mg_{0.1}-Zn_{(1-x-0.1)}{\cdot}Fe_2O_4]$-Rubber Composite에 관한 연구)

  • 박연준;김동일
    • Journal of the Korean Institute of Navigation
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    • v.22 no.4
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    • pp.69-75
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    • 1998

  • The super wideband electromagnetic wave absorber in RF-A-PF type has been proposed, which can be used for an anechoic chamber, wall material to prevent TV ghost, etc, In this paper, $Ni_x-Mg_{0.1}-Zn_(1-x-0.1){\cdot}Fe_2O_4$ Ferrite Powder has been fabricated. Using this, then, [$Ni_x-Mg_{0.1}-Zn_(1-x-0.1){\cdot}Fe_2O_4$-Rubber composite for RF-layer in the RF-A-PF type absorber has been fabricated and its characteristics has been analyzed. As a result, it has been shown that the $Ni_x-Mg_{0.1}-Zn_(1-x-0.1){\cdot}Fe_2O_4$-Rubber composit with the quantity $_x$ of $Ni_x$ between 0.5 and 0.6 is suitable for the RF-layer in the case of which the grain size is sub-micrometer order.

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Interlayer Coupling of CoFe/Cu/NiFe Trilayer Films

  • Baek, Jong-Sung;Lim, Woo-Woung;Lee, Soo-Hyung;Kim, Mee-Yang;Rhee, Jang-Roh
    • Journal of Magnetics
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    • v.5 no.4
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    • pp.139-142
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    • 2000

  • The interlayer coupling between adjacent ferromagnetic layers was examined for CoFe/Cu/NiFe trilayer systems. A series of films of CoFe (20 nm)/Cu($t_{cu}$)/NiFe (20 nm) trilayers with Cu spacer thickness, $t_{cu}$, in the range of 1~10 m was deposited on Si(100) wafers at room temperature by DC magnetron sputtering. In order to understand the dependence of the magnetic interaction between ferromagnetic $Co_{90}Fe_{10}$ (wt.%) and $Ni_{81}Fe_{19}$ (wt.%) layers separated by a nonmagnetic Cu spacer on the Cu layer thickness, we investigated the derivative ferromagnetic resonance (FMR) spectra. The FMR results were analyzed using the model of Layadi and Art-man for interlayer interaction. The interlayer coupling constant decreases in an oscillatory manner as the Cu spacer thickness increases up to 10 nm and approaches zero above 10 nm. The interlayer coupling constant is positive for all samples. Hence, it seems that the exchange coupling between adjacent CoFe and NiFe layers separated by a Cu layer is ferromagnetic.

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