• 제목/요약/키워드: inorganic materials

검색결과 1,813건 처리시간 0.027초

SoI-Gel법에 의한 Pb(Zr, Ti)$\textrm{O}_3$박막의 강유전체 특성 (Ferroelectric Properties of Sol-Gel Derived pb(Zr,Ti)$\textrm{O}_3$Thin Films)

  • 고가연;이은구;박진성;이종국;이우선;이재갑
    • 한국재료학회지
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    • 제7권6호
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    • pp.479-483
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    • 1997
  • Sol-gel법으로 제작한 여러 종류의 Zr/Ti비율을 갖고 있는 PZT박막의 전지적 특성과 신뢰성 특성을 상부 백금 전극을 sputtering으로 증착하고 Ar 기체로 반응성 이온 식각(RIE)방법으로 패턴을 형성한 후 열처리온도의 변화에 따라 조사하였다. Hysteresis loop특성을 되찾게 하였다. Zr/Ti 비율이 감소함에 따라 voltage shift가 증가하였으며 internal field가 없어지는 열처리 온도가 증가하였다. Zr/Ti비율이 감소함에 따라 초기 잔류 분극은 증가하였으나 switching 횟수가 증가됨에 따라 잔류 분극이 급속히 감소하였다.

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천연 황색안료 염색한지의 패션소재 적용 가능성 평가에 관한 연구 (Properties of Hanji with natural pigment dyeing for use as a fashion material)

  • 김기훈;임현아
    • 복식문화연구
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    • 제22권2호
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    • pp.339-345
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    • 2014
  • This study analyzes and compares Hanji made with loess to Hanji made with kaolin, two yellow-based inorganic pigments, in terms of its physical properties, optical properties, and color fastness to light with the aim of using it as a fashion material. Hanji made by adding inorganic pigments showed an approximately 20% retention ratio on average. This figure was similar to those of loess and kaolin. Physical properties were analyzed, with the following results. A higher amount of additives lowered the apparent density and increased thickness and bulk. In general, inorganic pigment-added Hanji had lower tensile strength, bursting strength, and folding endurance compared to non-additive Hanji. The analysis of optical properties showed a lower brightness index for Hanji made with inorganic pigments compared to non-additive Hanji. When comparing the two inorganic pigments, the brightness of Hanji made with kaolin was higher. Regarding color fastness to light, loess showed level 4 and kaolin showed level 5 when 25% inorganic pigments on pulp were added to Hanji. Thus, Hanji made by adding inorganic pigments during the manufacturing process may perform well as materials for fashion because the additives enhanced both the color fastness to light and the bulk while maintaining the strength. In addition, Hanji dyed with inorganic pigments may have the potential to serve as materials for the fashion industry while still retaining the characteristics of Hanji.

라이너지 공정수의 구성 성분이 종이의 물성에 미치는 영향 (The Effect of White Water Components on Mechanical Properties of Linerboard)

  • 윤혜정;류정용;송봉근;조미선
    • 펄프종이기술
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    • 제36권1호
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    • pp.9-15
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    • 2004
  • Micro inorganic solids and dissolved materials contained in the white water of linerboard process was obtained by centrifugation, and their characteristics were analyzed along with their effects on the mechanical properties of linerboard. Micro inorganic materials had little influence on tensile index and ZDT of UKP sheets. They showed rather a positive effect on mechanical properties of KOCC sheets due to adsorbed polymer. Mechanical properties of KOCC sheets decreased remarkably when the concentration of dissolved materials increased especially above 4000 ppm.

지르코니아 분말의 치밀화와 소결거동 : II. 소결거동 (Compaction and Sintering Behavior of Zirconia Powders : II. Sintering Behaviour)

  • 박홍채;김겸;김영우;이윤복;오기동
    • 한국세라믹학회지
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    • 제30권6호
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    • pp.449-456
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    • 1993
  • Sintering behaviour of zirconia powders prepared by different processing treatment was discussed. About >99% densities of theoretical were obtaiend on sintering at 140$0^{\circ}C$ for 2h in case of 300MPa uniaxially cold-pressed compact. But the lower densities were obtained on sintering above this temperature due to abnormal grain growth enabling the tetragonal to monoclinic phase transformation during cooling resulted in microcracks. All kinds of different dried powders exhibited nearly the same shrinkage behaviour with end-point shrinkage between 19 and 20%, and had maximum shrinkage rate (0.99~1.27%/min) around 120$0^{\circ}C$. During whole sintering process densification was mainly governed by grain growth and rearrangement of agglomerates. Heterogeneous abnormal grain growth and abrupt decrease in shrinkage were observed when continuous interagglomerate pore collapsed into isolated pores.

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박막공정의 융합화를 통한 초소형 고체산화물 연료전지의 제작: I. Spray Pyrolysis법으로 증착된 Ni 기반 음극과 스퍼터링으로 증착된 YSZ 전해질의 다층구조 (Fabrication of Micro Solid Oxide Fuel Cell by Thin Film Processing Hybridization: I. Multilayer Structure of Sputtered YSZ Thin Film Electrolyte and Ni-Based Anodes deposited by Spray Pyrolysis)

  • 손지원;김형철;김혜령;이종호;이해원
    • 한국세라믹학회지
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    • 제44권10호
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    • pp.589-595
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    • 2007
  • Physical properties of sputtered YSZ thin film electrolytes on anode thin film by spray pyrolisis has been investigated to realize the porous electrode and dense electrolyte multilayer structure for micro solid oxide fuel cells. It is shown that for better crystallinity and density, YSZ need to be deposited at an elevated temperature. However, if pure NiO anode was used for high temperature deposition, massive defects such as spalling and delamination were induced due to high thermal expansion mismatch. By changing anode to NiOCGO composite, defects were significantly reduced even at high deposition temperature. Further research on realization of full cells by processing hybridization and cell performance characterization will be performed in near future.

고분해능 전자에너지손실 및 자외선광전자 분광법을 이용한 NbC(111)면의 산소흡착 연구 (Oxygen Chemisorption of NbC(111) Surface Studied by High-Resolution Electron Energy Loss and Ultraviolet Photoelectron Spectroscopy)

  • 황연;박순자;아이자와 타카시;하야미 와타루;오타니 시게키;이시자와 요시오
    • 한국재료학회지
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    • 제2권4호
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    • pp.279-284
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    • 1992
  • 고분해능 전자에너지손실 및 자외선광전자 분광법을 사용하여 단결정 NbC(111)면의 산소횹착을 연구하였다. NbC(111) 표면에는 산소가 원자 및 분자상태로 흡착되었다. 산소원자는 3-fold hollow site에 흡착되며 진동수는 548c$m^{-1}$이었다. 산소분자의 신축진동수는 968c$m^{-1}$로서 기체상태인 산소분자의 진동수보다 크게 낮았으며, 산소분자의 흡착으로 일함수가 증가하였다. 이는 NbC(111) 기판으로부터 산소분자의 2p${pi}_g$ 궤도로 전자가 이동하였음을 보여주는 증거이다.

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고분해능 전자에너지손실 및 자외선광전자분광법을 이용한 ZrC(111)면의 산소흡착 연구 (Oxygen Chemisorption of ZrC(111) Surface by High-Resoltion Electron Energy Loss and Ultraviolet Photoelectron Spectroscopy)

  • 황연;박순자;아이자와 타카시;하야미 와타루;오타니 시게키;이시자와 요시오
    • 한국재료학회지
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    • 제1권4호
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    • pp.184-190
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    • 1991
  • 고분해능 전자에너지손실과 자외선광전자분광법을 사용하여 단결정 ZrC(111)면의 산소흡착을 연구하였다. 산소는 낮은 산소노출량에서 $(\sqrt{3}{\times}\sqrt{3})R30^{\circ}$ 구조로 흡착된다. 노출량이 승가하면 $1{\times}1$ 구조로 바뀌는데 이때 흡착하는 산소원자는 $(\sqrt{3}{\times}\sqrt{3})R30^{\circ}$ 구조에서보다 흡착높이가 낮으며 3-fold hollow site의 중심에 놓이지 않고 bridge site에 가까와진다. 서로 다른 산소흡착 거동은 개끗한 ZrC(111) 표면에서 두개의 표면전자상태에 기인한다.

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유리분말과 플라이애시를 사용한 내화성 경량 무기발포 소재 연구 (A Study of Fire-resistance Light-weight Inorganic Foam Material Using Cullet and Fly-ash)

  • 신현욱;송훈;추용식;이종규
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2011년도 추계 학술논문 발표대회
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    • pp.79-81
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    • 2011
  • To prevent energy waste in buildings used heat insulator. Heat insulator materials can be classified inorganic and organic. The organic material is due to toxic gas emission, when a fire occurs. And it has lower water resistance. The inorganic material is heavy and worse thermal performance than organic materials. This study focused on evaluation of the physical properties and fire-resistance of inorganic foam material for using industrial by-products materials for the applicability of Fire-resistance Light-weight material.

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고분자전해질 연료전지용 유기/무기 복합 전해질 (Organic / inorganic composite membrane for Polymer Electrolyte Membrane Fuel Cell)

  • 최성호;홍현실;이흥찬;김유미;김건
    • 한국전기화학회:학술대회논문집
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    • 한국전기화학회 2003년도 연료전지심포지움 2003논문집
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    • pp.169-171
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    • 2003
  • Organic/inorganic hybrid membranes have been prepared and evaluated as polymer electrolytes in a polymer electrolyte membrane fuel cell (PEMFC). Previously, partially fluorinated poly (arylenether) was synthesized and the polymer was sulfonated by fuming sulfuric acid$(30\%\;SO_3)$. Modification of these polymers with coupling agent and inorganic materials was carried out to prepare membranes. Membranes cast from these materials were investigated in relation to the proton conductivity and weight loss at the room temperature. It was found that these membranes had a higher conductivity of $10^{-2}\;Scm^{-1}$ at the room temperature. But inorganic materials have leaked out from the hybrid membrane. If this problem is resolved, organic/inorganic hybrid membranes will become satisfactory Polymer electrolytes for the PEMFC.

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