• 제목/요약/키워드: Fe-Pt

검색결과 442건 처리시간 0.034초

NOx제거를 위한 Fe/ZSM-5와 Co-Pt/ZSM-5의 상승 효과 (Synergy Effect of Fe/ZSM-5 and Co-Pt/ZSM-5 for NOx removal)

  • 김진걸;유승준;김성수
    • 한국산학기술학회논문지
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    • 제10권9호
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    • pp.2390-2395
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    • 2009
  • 공간속도 $30000\;hr^{-1}$에서 Fe/ZSM-5 촉매의 $SiO_2/Al_2O_3$ 몰비가 감소함에 따라 $NO_x$ 제거 수율은 증가하였다. Fe/ZSM-5는 반응 온도 $350^{\circ}C$ - $400^{\circ}C$ 사이에서 최대 50%의 질소 산화물 제거 수율을 나타내지만 높은 CO 발생량이 관찰된다. Fe/ZSM-5 촉매에서 생성되는 CO를 제거하기 위하여 Co-Pt/ZSM-5 촉매를 직렬로 연속하여 사용하였으며, 공간속도 $30000\;hr^{-1}$, 반응 온도 $250^{\circ}C$ 조건에서 90% 이상의 질소 산화물과 CO 제거 수율을 나타내었다.

Memory Characteristics of High Density Self-assembled FePt Nano-dots Floating Gate with High-k $Al_2O_3$ Blocking Oxide

  • Lee, Gae-Hun;Lee, Jung-Min;Yang, Hyung-Jun;Kim, Kyoung-Rok;Song, Yun-Heub
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.388-388
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    • 2012
  • In this letter, We have investigated cell characteristics of the alloy FePt-NDs charge trapping memory capacitors with high-k $Al_2O_3$ dielectrics as a blocking oxide. The capacitance versus voltage (C-V) curves obtained from a representative MOS capacitor embedded with FePt-NDs synthesized by the post deposition annealing (PDA) treatment process exhibit the window of flat-band voltage shift, which indicates the presence of charge storages in the FePt-NDs. It is shown that NDs memory with high-k $Al_2O_3$ as a blocking oxide has performance in large memory window and low leakage current when the diameter of ND is below 2 nm. Moreover, high-k $Al_2O_3$ as a blocking oxide increases the electric field across the tunnel oxide, while reducing the electric field across the blocking layer. From this result, this device can achieve lower P/E voltage and lower leakage current. As a result, a FePt-NDs device with high-k $Al_2O_3$ as a blocking oxide obtained a~7V reduction in the programming voltages with 7.8 V memory.

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FePt/MgO(100) 자성박막의 결정화 연구 (Crystallization of FePt/MgO(100) magnetic thin films)

  • 정지욱;조태식;이민수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.278-279
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    • 2005
  • The crystallization of FePt/MgO(100) magnetic thin films of various thicknesses has been studied using synchrotron x-ray scattering, atomic force microscope, and vibrating sample magnetometer. In film with a 500-${\AA}$-thick, ordered (fct) FePt phase was dominantly crystallized into perpendicular (001) grains keeping the magnetically easy c-axis normal to the film plane during annealing. In film with a 812-${\AA}$-thick, however, longitudinal (110) grains keeping the c-axis parallel to the film plane were grown on top of the perpendicular (001) grains. The behavior of the magnetic properties was consistent with the thickness dependence of the crystallization. We attribute the thickness dependence of the crystallization to the substrate effect, which prefers the growth of the c-axis oriented perpendicular grains near the film/substrate interfacial area.

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Synthesis and Characteristics of FePt Nanopowder by Chemical Vapor Condensation Process

  • Yu, Ji-Hun;Lee, Dong-Won;Kim, Byoung-Kee;Jang, Tae-Suk
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.1196-1197
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    • 2006
  • FePt binary-alloy nanopowder has been successfully synthesized by chemical vapor condensation process with two metal organic precursors, i.e., iron pentacarbonyl and platinum acetylacetonate. Average particle size of the powder was less than 50 nm with very narrow size distribution, revealing high dispersion capability. Characteristics of the powder could be controlled by changing process parameters such as reaction temperature, chamber pressure, as well as gas flow rate. Magnetic properties of the synthesized FePt nanopowder were investigated and analyzed in terms of the powder characteristics.

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저온형 연료전지용 산소의 고활성 환원 촉매 제조 (Preperation of catalyst having high activity on oxygen reduction)

  • 김영우;김형진;이주성
    • 한국에너지공학회:학술대회논문집
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    • 한국에너지공학회 1992년도 학술발표회 초록집
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    • pp.39-40
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    • 1992
  • This paper dealt with the manufacturing of binary alloy catalyst and showed simple electrochemical method for determing catalytic activity of oxygen reduction in acid or alkaline electrolyte. The catalyst was prepared by impregnating transition metal salts on platinum or silver particles adsorbed before on carbon paper substrate. The electrochemical characteristics of the catalysts was investigated with carbon paper electrode or PTFE-boned porous electrode and then cathodic current densities and tafel slopes were compared. As a result, of all binary catalysts utilized in this work, Pt-Fe, Pt-Mo showed better oxygen reduction activity than pure platinum catalyst in acid electrolyte and Ag-Fe, Ag-Pt, and Ag-Ni-Bi-Ti catalyst did than pure silver catalyst in alkaline electrolyte. The current density of Pt-Fe electrode in acid electrolyte was one and half times higher than that of Pt electrode(~500mA/$\textrm{cm}^2$ at 0.7VvsNHE).

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