• 제목/요약/키워드: $LaCoO_3$

검색결과 332건 처리시간 0.034초

ZnS:Mn/$ZnS:TbF_{3}$ 적층구조의 형광층을 이용한 TFEL소자의 제작 및 그 특성 (Fabrication and characteristics of TFEL device using phosphor layer ZnS:Mn/$ZnS:TbF_{3}$ slatted structure)

  • 박경빈;김호운;배승춘;김영진;조기현;김기완
    • 센서학회지
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    • 제6권1호
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    • pp.63-71
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    • 1997
  • ZnS:Mn/$ZnS:TbF_{3}$적층구조의 TFEL(thin-film eletroluminescent)소자를 제작하였으며, 이때 절연층으로 (Pb,La)$TiO_{3}$(이하PLT)와 $SiO_{2}$박막을 이용하였다. TFEL소자는 $78V_{rms}$의 문턱전압과 $100V_{rms}$의 인가전압에서 $400{\mu}W/cm^{2}$의 휘도를 나타내었다. TFEL소자의 발광스펙트럼은 450nm에서 630nm사이의 파장대를 보이고 있다. 제작된 TFEL소자는 컬러필터를 병용함으로서, 적 녹 청의 색상을 구현하는 TFEL소자로 활용할 수 있다.

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촉매 연소기용 촉매의 내구 성능 향상 연구 (Improvement of Durability Performance of Catalysts for a Catalytic Combustor)

  • 최병철;유진상;서용석;정필수
    • 융복합기술연구소 논문집
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    • 제9권1호
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    • pp.7-12
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    • 2019
  • The aim of this study is to improve the durability performance of catalysts for a catalytic combustor and to obtain operating conditions for stable combustion of the catalytic combustor. It was attempted to improve the durability of the catalysts by adding a promoter in order to reduce the cost of replacing Pt catalyst while maintaining stability. The main catalyst used in the study was Pt and the promoters were Ni and La. Pure Pt3/γ-Al2O3 catalyst without promoter was promoted to fast sintering states under harsh conditions and catalytic combustion was turned off, whereas the catalysts added La, Ni as promoter were showed relatively slow sintering states. It can be concluded that the promoter La, Ni effectively contributes to the improvement of the durability of the Pt catalyst, and it is possible to get longer durability and more stable duration than the conventional catalytic combustor.

솔-젤 법을 이용한 Pb(Zr, Ti)$O_3$ 박막의 성장 및 전기적 특성에 관한 연구 (Growth and electrical properties of Pb(Zr, Ti)$O_3$ thin films by sol-gel method)

  • 김봉주;전성진;이재찬;유지범
    • 한국진공학회지
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    • 제8권4A호
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    • pp.425-431
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    • 1999
  • $Pb(Zr_{0.52}, Ti_{0.48})O_3$ (PZT) thick films as an actuating material with conducting oxides, $(La_{0.5}Sr_{0.5}) CoO_3$ (LSCO), have been fabricated by sol-gel method for Optical Micro-Electro-Mechanical System (MEMS) devices, in which PZT/LSCO/SiO2 structures were used. In order to improve the adhesion to LSCO solution in order to enhance the wetting behavior of a water-based LSCO precursor solution and further to improve the adhesion between LSCO and $SiO_2$ layers. PZT films were made using 1-3 propanediol based precursor solution which has a high viscosity and a boiling point appropriate for thick film fabrication. In the precursor solution, Ti-propoxied and Zr-propoxied are partially substituted with acetylacetone to achieve the solution stability while maintaining reactivity. Crack free PZT films (0.8~1$\mu\textrm{m}$) have been successfully fabricated at crystallization temperatures above $700^{\circ}C$. Dielectric constants and dielectric losses of the PZT films were 900~1200and 2~5%, respectively. Piezoelectric constant $d_{33}$ of the PZT films constrained by a substrate were 200pm/V at 100kV/cm.

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메탄의 완전산화 반응을 위한 중공사형 페롭스카이트 촉매 제조 (Preparation of the Hollow Fiber Type Perovskite Catalyst for Methane Complete Oxidation)

  • 이성운;김은주;이홍주;박정훈
    • Korean Chemical Engineering Research
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    • 제56권3호
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    • pp.297-302
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    • 2018
  • 선행 연구를 통해서 우수한 메탄 완전 산화 특성을 보인 $La_{0.1}Sr_{0.9}Co_{0.2}Fe_{0.8}O_{3-{\delta}}$ (LSCF1928) 페롭스카이트 분말 촉매로 비드형과 중공사형 촉매를 제조하였다. 중공사형 촉매는 내부가 비어있는 원기둥 형태이며, 상전이법을 통해 기공을 형성시킬 수 있어 비표면적을 획기적으로 향상시킬 수 있다. Methyl Cellulose (MC)를 넣어 제조한 비드형 촉매의 경우 MC에서 배출되는 $CO_2$와 촉매 성분인 Sr이 반응하여 원래 촉매 조성이었던 LSCF1928 조성 외에 $SrCO_3$가 생성되었다. 중공사형 촉매의 경우 불순물 없이 단일상의 페롭스카이트 구조를 얻었다. $700{\sim}900^{\circ}C$에서 하소한 중공사형 촉매는 손가락구조-스펀지구조-손가락구조의 기공 형태를 보였으며, 모두 $475^{\circ}C$에서 메탄의 완전 산화 반응을 통해 99.9% 산소 전화율을 달성하였다. 중공사형 촉매의 기공을 제어하기 위하여 에어 갭과 방사압력 조건을 변경하였다. 2 cm 에어 갭, 7 bar의 방사 압력으로 제조한 중공사형 촉매가 가장 우수한 촉매 성능을 보였으며, $425^{\circ}C$, $450^{\circ}C$$475^{\circ}C$에서 각각 70.65%, 93.01%, 99.99% 이상의 산소 전화율을 달성하였다.

Enhanced Performance of La0.6Sr0.4Co0.2Fe0.8O3-\delta (LSCF) Cathodes with Graded Microstructure Fabricated by Tape Casting

  • Nie, Lifang;Liu, Ze;Liu, Mingfei;Yang, Lei;Zhang, Yujun;Liu, Meilin
    • Journal of Electrochemical Science and Technology
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    • 제1권1호
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    • pp.50-56
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    • 2010
  • $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-\delta}$ (LSCF) powders with different particle sizes, synthesized through a citrate complexation method and a gel-casting technique, are used to fabricate porous LSCF cathodes with graded microstructures via tape casting. To create porous electrodes with desired porosity and pore structures, graphite and starch are used as pore former for different layers of the graded cathode. Examination of the microstructures of the as-prepared LSCF cathode using an SEM revealed that both grain size and porosity changed gradually from the catalytically active layer (near the electrodeelectrolyte interface) to the current collection layer (near the electrode-interconnect interface). Impedance analysis showed that a 3-layer LSCF cathode with graded microstructures exhibited much-improved performance compared to that of a single-layer LSCF cathode, corresponding to interfacial resistance of 0.053, 0.11, and 0.27 $\Omega{\cdot}cm^2$ at 800, 750, and $700^{\circ}C$ respectively.