• Title/Summary/Keyword: Co film

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LCD BLU Optical Film Market and Technology Trends

  • Huh, Jong-Wook
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.151-151
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    • 2009
  • In this presentation, CD BLU optical film market and technology trends are introduced at first. Then hghly precise, cost-advantaged MNTECH's specialized Soft Mold replication Technology and its optic films are contained.

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Soft Magnetic Properties of CoFeAlO Thin Films for Ultrahigh Frequency Applications (고주파용 CoFeAlO계 박막의 자기적 특성)

  • Kim, Hyeon-Bin;Yun, Dae-Sik;Ha, N.-D.;Kim, Jong-O
    • Journal of the Korean Magnetics Society
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    • v.15 no.1
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    • pp.17-20
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    • 2005
  • The influence of $O_2$ partial pressure on saturation mgnetization, coercivity, anisotropy field and effective permeability (over 1GHz) of as-deposited Co-Fe-Al-O thin films, which were fabricated by RF magnetron reactive sputtering method, were investigated. The $Co_{69.9}Fe_{20.5}A_{14.4O_{5.2}$ thin film fabricated at $O_2$ partial pressure of 4% exhibits the best magnetic softness with saturation magnetization 4${$pi}$Ms of 18.1 kG, coercivity of 0.82 Oe, anisotropy field ($H_k$) of Oe, and effective permeability (${\mu}_{eff}$) about 1,024 above 1 GHz. the electrical resistivity of Co-Fe-Al-O thin films were increased with increasing $O_2$ partial pressure, the electrical resistivity of $Co_{69.9}Fe_{20.5}A_{14.4O_{5.2}$ thin film with the best soft magnetic properties was 560.7 ${\mu}{\Omega}$am. Therefore, It is assumed that the good soft magnetic properties of $Co_{69.9}Fe_{20.5}A_{14.4O_{5.2}$ thin film results from high electrical resistivity and large anisotropy field.

Exchange Bias Study by FMR Measurment (강자성 공명에 의한 Exchange Bias 연구)

  • Yoo, Yong-Goo;Park, Nam-Seok;Min, Seong-Gi;Yu, Seong-Cho
    • Journal of the Korean Magnetics Society
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    • v.15 no.5
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    • pp.265-269
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    • 2005
  • Exchange bias effect of a various layered thin films were studied by FMR measurment. In plane angular dependence of a resonance field distribution which measured by FMR was analysed as a combined effect of an unidirectional anisotropy and an uniaxial anisotropy. Exchange biased NiFe/IrMn, IrMn/NiFe/IrMn, and NiFe/IrMn/CoFe thin films showed larger unidirectional anisotropy field and uniaxial anisotropy field with compared to that of an unbiased NiFe single thin film. In case of NiFe/Cu/IrMn, the film with thick Cu layer exhibited a similar trend to the unbiased NiFe thin film. NiFe/IrMn/CoFe thin film showed two resonance field distribution due to different ferromagnetic layers. In additon to the resonance field, the line width was also analysed with related to exchange bias effect.

Effect of Annealing on the Magnetic Anisotropy of Amorphous $Co_{89}Nb{8.5}Zr{2.5}$Thin Films ($Co_{89}Nb{8.5}Zr{2.5}$ 비정질 박막의 이방성에 미치는 열처리 효과)

  • 김현식;민복기;송재성;오영우
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.6
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    • pp.486-492
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    • 1998
  • The amorphous Co-based magnetic films have a large saturation flux density, a low coercive force, and a zero magnetostriction constant. Therefore, they have been studied for application to magnetic recoding heads and micro magnetic devices. However, it was found that the magnetic anisotropy was changed for each film fabrication processes. In this study, we investigated how to control the anisotropy of sputtered amorphous $Co_{89}Nb{8.5}Zr{2.5}$ films. After deposition, the rotational field annealing ant the uniaxial field annealing were performed under the magnetic field of 1.5 kOe. the annealing was done at the temperature range from 400 to $600^{\circ}C$ for one hour. As-deposited amorphous $Co_{89}Nb{8.5}Zr{2.5}$ thin film had saturation magnetization ($4\piM_5$) of 0.8 T, coercive force($_IH_C$) of 1.5 Oe, and anisotropy field($H_k$) of 11 Oe. The amorphous $Co_{89}Nb{8.5}Zr{2.5}$ thin films annealed by rotational field annealing at $500^{\circ}C$ for one hour was found to be isotropy, and $4\piM_5$ of 0.9 T was obtained from these films, Also, the magnetic anisotropy of as-deposited films could be controlled by uniaxial field annealing at $400^{\circ}C$ for one hour. Anisotropy field($H_k$) of 17 Oe and $4\piM_5$ of 1.0 T were obtained by this method.

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Fabrication and Characterization of Environmentally Friendly PLA/PPC/PLA Multilayer Film (친환경 PLA/PPC/PLA 적층필름의 제조 및 특성 연구)

  • Lee, Deuk-Young;Kim, Kyung-Youn;Cho, Misuk;Nam, Jaedo;Lee, Youngkwan
    • Polymer(Korea)
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    • v.37 no.2
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    • pp.249-253
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    • 2013
  • From poly(lactic acid) (PLA) and poly(propylene carbonate) (PPC) synthesized using $CO_2$, a PLA/PPC/PLA layered film is prepared by coextrusion and then stretched to uniaxial orientation. The mechanical, optical, and barrier properties and shrinkage of the prepared film were investigated in detail. The maximum shrinkage of PLA/PPC/PLA film reached to 60% at $75^{\circ}C$. With increasing PPC content, the ratio of shrinkage of the film was increased and its shrinkagerate was increased. The ratio of shrinkage of the film decreased with increasing stretching temperature. The prepared film has oxygen and vapor transmission barrier properties. In this study, the PLA/PPC/PLA film is expected to be commercialized as a environmentally friendly shrinkable film.

A Study of Relationship between Magnetic Properties and Microstructure of CoNiCr/Cr Double Layer Thin Film Magnetic Recording Media (자기기록매체 CoNiCr/Cr 이중박막의 자기적 성질과 미세구조와의 관계연구)

  • 김희삼;남인탁;홍양기
    • Journal of the Korean Magnetics Society
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    • v.3 no.3
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    • pp.215-220
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    • 1993
  • Microstructural dependence of magnetic property of RF/DC sputtered $Co_{69.0}Ni_{18.5}Cr_{12.5}/Cr$ double layer thin film was studied. Grain size was found to be decreased with substrate temperature in the range of $100-200^{\circ}C$ and Cr underlayer thickness(from $500\;{\AA}-2000\;{\AA}$). The peaks (200) and (1120) of X-ray diffraction patterns were evidently grown with the substrate temperature for the Cr underlayer and magnetic layer, respectively. The CoNiCr magnetic layer was found to be well epitaxialy grown on Cr underlayer, and subsequently the coercivity was enhanced.

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Changes in the electrochemical properties of air-formed oxide film-covered AZ31 Mg alloy in aqueous solutions containing various anions

  • Fazal, Basit Raza;Moon, Sungmo
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2017.05a
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    • pp.96.2-96.2
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    • 2017
  • This research was conducted to investigate the electrochemical properties of the thin air-formed oxide film-covered AZ31 Mg alloy. In this work, native air-formed oxide films on AZ31 Mg alloy samples were prepared by knife-abrading method and the changes in the electrochemical properties of the air-formed oxide film were investigated in seven different electrolytes containing the following anions $Cl^-$, $F^-$, $SO{_4}^{2-}$, $NO_3{^-}$, $CH_3COO^-$, $CO{_3}^{2-}$ and $PO{_4}^{3-}$. It was observed from open circuit potential (OCP) transients that the potential initially decreased before gradually increasing again in the solutions containing only $CO{_3}^{2-}$ or $PO{_4}^{3-}$ ions, indicating the dissolution or transformation of the native air-formed oxide film into new more protective surface films. The Nyquist plots obtained from electrochemical impedance spectroscopy (EIS) showed that there was growth of new surface films with immersion time on the air-formed oxide film-covered specimens in all the electrolytes; the least resistive surface films were formed in fluoride and sulphate baths whereas the most protective film was formed in phosphate bath. The potentiodynamic polarization curves illustrated that passive behaviour of AZ31 Mg alloy under anodic polarization appears only in $CO{_3}^{2-}$ or $PO{_4}^{3-}$ ions containing solutions and at more than $-0.4V_{Ag/AgCl}$ in $F^-$ ion containing solution.

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Studies on Formation of Passivation Film on KMFC Anode with Initial Charge Temperature (탄소 부극에서 초기 충전온도별 부동태 피막 형성에 대한 연구)

  • Park, Dong-Won;Kim, Woo-Seong;Choi, Yong-Kook
    • Applied Chemistry for Engineering
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    • v.16 no.4
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    • pp.507-512
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    • 2005
  • When carbon electrode is used as an anode in Li ion battery, passivation film forms on the electrode surface during the initial charge process due to so called Solid-Electrolyte Interphase (SEI). The passivation film formed by solvent decomposition during the initial charge process affects charge/discharge capacity. In this paper, 1 M $LiPF_6,EC:DEC$ (1 : 1, volume ratio) electrolyte with $Li_2CO_3$, at various temperatures, the electrochemical characteristics of passivation film formed on Kawasaki Mesophase Fine Carbon electrode surface were investigated by using chronopotentiometry, cyclic voltammetry, and impedance spectroscopy. Experimental observations indicated that as solvent decomposition occurred, the decomposition voltage was strongly dependent on ionic conductivity, which was low in the process at low temperature. The impedance of passivation film formed during the initial charge process, were dependent on the temperature.

The Effects of Drying Temperature on Chromate Treatment for Electroplated Zinc (전기 아연도금용 유색 크로메이트에 대한 건조 온도의 영향)

  • Su-Byung Jeon;Ji-Won Choi;Byung-Ki Son;Injoon Son
    • Journal of the Korean institute of surface engineering
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    • v.56 no.5
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    • pp.289-298
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    • 2023
  • In this study, the effect of drying temperature on characteristics of the trivalent chromate film on electroplated zinc was investigated. An zinc-electroplated iron specimen with a thickness of 5 ㎛ was used for chromate treatment. Chromate treatment was conducted in a solution diluted 10 times from a mixture of Cr(NO3)3·9H20 360 g/L, Co(NO3)2·6H2O 60 g/L, Na2SO4 60 g/L, NH4F·HF 25 g/L, and NaOH 20 g/L. The zinc electroplated specimen was treated using the chromate solution with pH 2.0 at 25 ℃ for 60 s. Subsequently, chromate-treated samples were dried in an electric furnace for 2h with temperature varied from 25 to 125 ℃. The corrosion rate increased with the increase in the drying temperature, and the surface morphology of the chromate-treated film was observed using FE-SEM. When the drying temperature changed, the color of the chromate film changed from green to yellow, and the thickness of the film changed from 362 to 241 nm, respectively. Additionally, corrosion resistance was evaluated via a salt spray test.

Nano-granular Co-Fe-Al-Q Soft Ferromagnetic Thin Films for RF Electromagnetic-noise Filters

  • Sohn, Jae-Cheon;Byun, Dong-Jin
    • Transactions on Electrical and Electronic Materials
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    • v.7 no.1
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    • pp.42-50
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    • 2006
  • Co-Fe-Al-O nano-granular thin films with high electrical resistivity, fabricated by radio frequency magnetron sputtering under an $Ar+O_2$ atmosphere, are found to show good soft magnetic properties in the GHz frequency range. The real part value of the relative permeability is 260 at low frequencies and this value is maintained up to the GHz frequency range. A non-integrated type noise filter on a coplanar waveguide transmission line is demonstrated by using the Co-Fe-Al-O nano-granular thin film with the dimensions of $4\;mm(l){\times}4\;mm(w){\times}0.1\;{\mu}m(t)$. The insertion loss is very low being less than 0.3 dB and this low value is maintained up to 2 GHz. At a ferromagnetic resonance frequency of 3.3 GHz, the degree of noise suppression is measured to be 3 dB. This level of noise attenuation is small for real applications, but there is much room for further improvement by increasing the magnetic volume and integrating the magnetic thin film into the CPW transmission line.