• Title/Summary/Keyword: Soft magnetics

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Observation of the Domain Structures in Soft Magnetic (Fe97A13)85N15/Al2O3 Multilayers

  • Stobiecki, T.;Zoladz, M.
    • Journal of Magnetics
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    • v.8 no.1
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    • pp.13-17
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    • 2003
  • The longitudinal magnetooptical Kerr effect was used to analyse magnetic domains in soft magnetic ${(Fe_{97}A1_3)}_{85}N_{15}$/$Al_{2}O_{3}$ multilayers in order to get microscopic understanding of interlayer exchange coupling. The measuring system consists of a Kerr microscope, a CCIR camera (with an 8-bit framegrabber), 16 bit digital camera and computer system for real-time image processing and to control external magnetic field and cameras. The strength of ferromagnetic (EM) coupling as a function of the spacer thickness of $Al_2O_3$ was investigated. It was found that strong FM-coupling, strong uniaxial anisotropy and coherent rotation of the magnetization have been observed for the spacer thickness in the range of 0.2 nm $\leq$ t $\leq$ 1 m, however, weak FM-coupling, patch domains and $360^{\circ}$-walls occur for the spacer thickness of t = 2.5 nm. At a spacer thickness of t $\geq$ 5 nm transition takes place from weak FM-coupling to the decoupled state where complex interlayer interactions and different types of the domain walls were observed.

Effect of Residual Impurity on Magnetic Properties of the Permalloy Soft Magnet by Powder Injection Molding (분말사출성형으로 제조된 퍼말로이 연자성체에서 잔류 불순물이 자기특성에 미치는 영향)

  • 정원용;최준환;정우상
    • Journal of the Korean Magnetics Society
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    • v.10 no.6
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    • pp.291-296
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    • 2000
  • The manufacturing method of permalloy soft magnet with the Ni contents of 46.6 and 47.2 wt% was investigated by powder injection molding technology. The magnetic properties of permalloy were greatly affected on the residual carbon and oxygen content of the sintered magnet. Solvent extraction and thermal debinding process to minimize the residual carbon content in sintered magnet were developed by controlling the debinding atmosphere. The residual carbon content depends on the debinding condition of the binder system for powder injection molding and the residual oxygen content on the sintering atmosphere. The sintered magnet produced by powder injection molding process had a 50 ppm. residual carbon, 150 ppm. residual oxygen. The coercivity and maximum relative permeability of permalloy soft magnet were 0.46 Oe and 14,600 respectively.

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RF Integrated Electromagnetic-Noise Filters Incorporated with Nano-granular Co41Fe38AI13O8 Soft Magnetic Thin Films on Coplanar Transmission Line

  • Sohn, Jae-Cheon;Yamaguchi Masahiro;Lim, Sang-Ho;Han, Suk-Hee
    • Journal of Magnetics
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    • v.10 no.4
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    • pp.163-170
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    • 2005
  • The RF integrated noise filters are fabricated by photolithography. The stack for the electromagnetic noise filters consists of the nano-granular ($Co_{41}Fe_{38}AI_{13}O_8$) soft magnetic film / $SiO_2$ / Cu transmission line / seed layer (Cu/Ti) / $SiO_2$-substrate. A good signal-attenuation feature along with a low signal-reflection feature is observed in the present filters. Especially in the noise filter incorporated with a $Co_{41}Fe_{38}AI_{13}O_8$ magnetic film with lateral dimensions of $2000{\mu}m$ wide, 15 mm long and $1{\mu}m$ thick, the maximum magnitude of signal attenuation reaches -55 dB, and the magnitude of signal reflection is below -10 dB in the overall frequency range. And this level of signal attenuation is much larger than that of a noise filter incorporated with a Fe magnetic film.

A STUDY ON THE SOFT MAGNETIC PROPERRTIES OF Fe-Ta-(N,C) NANOCRYSTALLINE THIN FILMS

  • Shin, Dong-Hoon;Ahn, Dong-Hoon;Kim, Hyoung-June;Nam, Seung-Eui
    • Journal of the Korean Magnetics Society
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    • v.5 no.5
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    • pp.601-605
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    • 1995
  • Magnetic properties of FeTaN and FeTaC films deposited by DC magnetron reactive sputter were investigated, and correlated with their microstructures. The optimum magnetic properties of Hc : 0.25 Oe, Bs : 14.5 kG, and ${\mu}'$ : 4000 (5MHz) are observed in the $Fe_{78.8}Ta_{8.5}N_{12.7}$ film, and Hc : 0.25 Oe, Bs : 14.5 kG, and ${\mu}'$ : 2700 (5MHz) in the $Fe_{75.6}Ta_{8.1}C_{16.3}$ film. In both FeTaN and FeTaC films with minimum grain size show the best soft magnetic properties. Thermal stability of the soft magnetic properties of FeTaN is found to be higher than FeTaC for similar compositons. TaN and TaC particles form to retard the growth of $\alpha$-Fe grains. TaN particles in FeTaN show higher efficiency in retarding the grain growth during heat treatments resulting the higher thermal stability, compared to TaC particles in FeTaC films.

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MAGNETIC PROPERTIES OF MELT-SPUN $F_{86-x}Al_{4}B_{10}Zr_{x}$ AMORPHOUS ALLOYS

  • Kim, K.J.;Park, J.Y.;Kim, K.Y.;Lee, J.S.;Noh, T.H.
    • Journal of the Korean Magnetics Society
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    • v.5 no.5
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    • pp.487-490
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    • 1995
  • With the object of developing a new magnetic core materials for high frequency use, the crystallization behaviors and the soft magnetic properties of amorphous $F_{86-x}Al_{4}B_{10}Zr_{x}\;(5{\leq}x{\leq}10\;at%)$ alloys subjected to annealing treatment at wide temperature range were investigated. For optimally annealed $Fe_{86-x}Al_{4}B_{10}Zr_{x}$ alloys in amorphous state, rather good soft magnetic properties of ${\mu}_{e}=17000~25000,\;H_{c}=20~30$ mOe and $B_{10}{\geq}0.6$ T are obtained. However, as the alloys crystallize, the soft magnetic properties are largely dergely deteriorated, which is attributed principally to the narrow temperature gap between $T_{x1}$ and $T_{x2}$, which allows the nearly co-precipitation of bcc phase and Fe-B compounds in incipient crystallization stage.

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