• Title/Summary/Keyword: IrMn

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Exchange Coupling Effect on Microwave Permeability in CoFe/MnIr Bilayers (교환 결합력을 갖는 CoFe/MnIr 박막의 마이크로파 투자율 특성)

  • Kim, Dong-Young;Kim, Chong-Oh;Kim, Cheol-Gi;Tsunoda, M.;Takahashi, M.
    • Journal of the Korean Magnetics Society
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    • v.16 no.5
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    • pp.234-239
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    • 2006
  • We measured the microwave permeability in the frequency range of 100 MHz$\sim$9 GHz in the exchange biased CoFe/MnIr films. The results were analyzed based on the Landau-Lifshitz-Gilbert theory. The initial permeability and ferromagnetic resonance frequency was tuned by controlling the CoFe thickness and unidirectional anisotropy. The tunable range of ferromagnetic resonance frequency was up to 20 GHz in the thin CoFe layer of 1.5 nm. The CoFe/MnIr films showed the high permeability and low loss properties in the microwave frequency range. Thus, this material could be applied to the microwave devices.

Preparation and Characterization of La0.8Ca0.2MnO3 (La0.8Ca0.2MnO3의 합성 및 특성연구)

  • 정미원;이지윤;김현정
    • Journal of the Korean Ceramic Society
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    • v.40 no.5
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    • pp.434-440
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    • 2003
  • The powders of L $a_{0.8}$C $a_{0.2}$Mn $O_3$ Colossal Magnetoresistance (CMR) materials were synthesized by sol-gel process. Lanthanum(H), Calcium(II) and Manganese(III) 2,4-Pentanedionate were dissolved in a mixed binary solution consisted of propionic acid and methanol with PEG (15 wt%) aqueous solution. The progress of reactions was monitored by FT-IR spectroscopy. The Lao scao.2Mn03 gel powders were annealed at various temperatures. The structural changes were investigated by FT-IR, CP/MAS $^{ 13}$C solid state NMR spectroscopy and XRD. The thermochemical property, particle characterization, microstructure of sintered sample, and cation composition of gel powder were studied by TG/DTA, FE-SEM and ICP-AES. The magnetic characterizations were identified through measurement of magnetic moment by VSM.

Shape Magnetic Anisotropy on Magnetic Easy Axis of NiFe/Cu/NiFe/IrMn Spin Valve Thin Film (NiFe/Cu/NiFe/IrMn 스핀밸브 박막소자의 자화 용이축에 따른 형상 자기이방성)

  • Choi, Jong-Gu;Kwak, Tae-Joon;Lee, Sang-Suk;Sim, Jung-Taek
    • Journal of the Korean Magnetics Society
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    • v.20 no.2
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    • pp.35-40
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    • 2010
  • The GMR-SV (giant magnetoresistance-spin valve) device depending on the micro patterned features according to two easy directions of longitudinal and transversal axes has been studied. The GMR-SV multilayer structure was Ta(5 nm)/NiFe(8 nm)/Cu(2.3 nm)/NiFe(4 nm)/IrMn(8 nm)/Ta(2.5 nm). The applied anisotropy direction of the GMR-SV thin film was performed under the magnitude of 300 Oe using by permanent magnet during the deposition. The size of micro patterned device was a $1\;{\times}\;18\;{\mu}m^2$ after the photo lithography process. In the aspects of the shape magnetic anisotropy effect, there are two conditions of fabrication for GMR-SV device. Firstly, the direction of sensing current was perpendicular to the magnetic easy axis of the pinned NiFe/IrMn bilayer with the transversal direction of device. Secondly, the direction of shape magnetic anisotropy was same to the magnetic easy axis of the free NiFe layer with the longitudinal direction of device.