• 제목/요약/키워드: XPS.

검색결과 2,180건 처리시간 0.031초

Pt합금 촉매에서 메탄을 산화 반응에 미치는 제2금속의 영향 (The Effects of 2nd Metals in Pt-based Electrocatalysts on Methanol Oxidation)

  • 김영민;박경원;최종호;박인수;성영은
    • 한국전기화학회:학술대회논문집
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    • 한국전기화학회 2002년도 연료전지심포지움 2002논문집
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    • pp.179-182
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    • 2002
  • The electrooxidation of methanol was studied using Pt, PtRu(1:1), PtNi(1:1), PtRh(1:1) and PtOs(1:1) alloy nanoparticles for application as electrocatalysts. The effects of the second metals in the electrocatalytic activity was investigated using cyclic voltammetry (CV), chronoamperometry (CA), X-ray photoelectron spectroscopy (XPS). There are the metallic and oxygen states in the PtRu and PtOs electrocatalysts . In the XPS of PtRu and PtOs alloy nanoparticles, the oxygen sources were dominant as the second metal's effects. Negative shifts of the binding energies of Pt for the PtNi, PtRh alloy nanoparticles were determined by XPS measurements, which can be explained by electronic effects.

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자외선 조사된 Poly(ethylene terephthalate) 필름의 표면 열화 분석 (Analysis of the Surface Degradation in UV-irradiated Poly(ethylene terephthalate) films)

  • 임경범;김종윤;최훈영
    • 전기학회논문지
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    • 제59권12호
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    • pp.2230-2234
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    • 2010
  • This paper deals with the change of surface potential decay, surface resistivity, contact angle and XPS of ultraviolet-treated PET films. From the experimental results on the surface potential decay of UV degraded-samples, it was found that the accumulation of charge is decreased and the surface potential decay time is shortened. Also, from the result of XPS, it was found that the changes affected by the surface degradation of PET film were caused by the generation of carboxyl groups through the chain decomposition and recombination with oxygen molecules in the air.

MEICP에 의한 (Ba,Sr)$TiO_3$ 박막의 식각 메커니즘에 관한 연구 (A Study on the Etching Mechanism of (Ba,Sr)$TiO_3$ Thin Films using MEICP)

  • 민병준;김창일
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
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    • pp.52-55
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    • 2000
  • In this study, (Ba,Sr)$TiO_3$(BST) thin films were etched with a magnetically enhanced inductively coupled plasma(MEICP) as a function Ar/$CF_4$ gas mixing ratio. Experiment was done by varying the etching parameters such as rf power, dc bias voltage and chamber pressure. The maximum etch rate of the BST films was 1700 ${\AA}/min$ under $CF_4/(CF_4+Ar)$ of 0.1, 600 W/350 V and 5 mTorr. The selectivity of BST to Pt and PR was 0.6, 0.7, respectively. X -ray photoelectron spectroscopy(XPS) studies shows that there are surface reaction between Ba, Sr, Ti and C, F radicals during the etching. To analyze the composition of surface residue remaining after the etching, films etched with different $CF_4$/Ar gas mixing ratio were investigated using XPS.

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$CF_4$/Ar 플라즈마에 의한 BST 박막 식각 특성 (Etching Characteristics BST Thin Film in $CF_4$/Ar Plasma)

  • 김동표;김창일;서용진;이병기;장의구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.866-869
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    • 2001
  • In this study, (Ba,Sr)TiO$_3$(BST) thin films were etched with a magnetically enhanced inductively coupled plasma(MEICP). Etching characteristics of BST thin films including etch rate and selectivity were evaluated as a function of the etching parameters such as gas mixing ratio, rf power, dc bias voltage and chamber pressure. The maximum etch rate of the BST films was 1700 $\AA$/min at Ar(90)/CF$_4$(10), 600 W/350 V and 5 mTorr. The selectivity of BST to PR was 0.6, 0.7, respectively. To analyze the composition of surface residue remaining after the etching, samples etched with different CF$_4$/Ar gas mixing ratio were investigated with X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). From the results of XPS and SIMS, there are chemical reaction between Ba, Sr, Ti and C, F radicals during the etching and remained on the surface.

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Preparation of Tantalum Anodic Oxide Film in Citric Acid Solution - Evidence and Effects of Citrate Anion Incorporation

  • Kim, Young-Ho;Uosaki, Kohei
    • Journal of Electrochemical Science and Technology
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    • 제4권4호
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    • pp.163-170
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    • 2013
  • Tantalum anodic oxide film was prepared in citric acid solution of various concentrations and the prepared Ta anodic oxide film was characterized by various electrochemical techniques and X-ray photoelectron spectroscopy (XPS). The prepared Ta anodic oxide film showed typical n-type semiconducting properties and the dielectric properties were strongly dependent on the citric acid concentration. The variation of electrochemical and electronic properties was explained in terms of electrolyte anion incorporation into the anodic oxide film, which was supported by XPS measurements.

An XPS Study of Oxyfluorinated Multiwalled Carbon Nano Tubes

  • Yun, Seok-Min;Kim, Ju-Wan;Jung, Min-Jung;Nho, Young-Chang;Kang, Phil-Hyun;Lee, Young-Seak
    • Carbon letters
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    • 제8권4호
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    • pp.292-298
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    • 2007
  • In order to investigate functional groups on the surface of Multi-walled Carbon Nanotubes (MWCNTs) induced by oxyfluorination, XPS (X-ray photoelectron spectroscopy) analysis was carried out. All core level spectra of MWCNTs were deconvoluted to several Pseudo-Voigt functions (sum of Gaussian-Lorentzian functions). Both O1s and F1s binding energy of oxyfluorinated MWCNTs shifted high value as increment of fluorine mixing ratio. The carbon-fluorine covalent bonding concentration increased as increment of fluorine mixing ratio. The shape and intensity of OF10-MWCNTs are similar with those of as-received MWCNTs. However, the intensity and binding energies of main peak position of OF20-MWCNTs and OF30-MWCNTs were dramatically increased by oxyfluorination.

Adsorption mechanism of copper ions on porous chitosan membranes: Equilibrium and XPS study

  • Ghaee, Azadeh;Zerafat, Mohammad Mahdi
    • Membrane and Water Treatment
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    • 제7권6호
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    • pp.555-571
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    • 2016
  • Heavy metal contamination has attracted considerable attention during recent decades due to the potential risk brought about for human beings and the environment. Several adsorbent materials are utilized for the purification of contaminated water resources among which chitosan is considered as an appropriate alternative. Copper is a heavy metal contaminants found in several industrial wastewaters and its adsorption on porous and macroporous chitosan membranes is investigated in this study. Membranes are prepared by phase inversion and particulate leaching method and their morphology is characterized using SEM analysis. Batch adsorption experiments are performed and it is found that copper adsorption on macroporous chitosan membrane is higher than porous membrane. The iso-steric heat of adsorption was determined by analyzing the variations of temperature to investigate its effect on adsorption characteristics of macroporous chitosan membranes. Furthermore, desorption experiments were studied using NaCl and EDTA as eluants. The mechanism of copper adsorption was also investigated using XPS spectroscopy which confirms simultaneous occurrence of chelation and electrostatic adsorption mechanisms.

유럽 및 비유럽권역의 REACTION-TO-FIRE에 대한 XPS 관련 규정 적용성 검토 (REVIEW OF REACTION-TO-FIRE REQUIREMENTS' APPLICATION IN EU & NON-EU BASED ON XPS INSULATION)

  • 박계원;정재군
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2011년도 춘계학술논문발표회 논문집
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    • pp.127-130
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    • 2011
  • This paper is about an recent overview of the fire regulations of several countries as for the use of XPS related insulation in building application. The data compiled in this paper is based both on in-house expertise at SP Fire Technology, in particular in relation to European Building legislation, and on replies to a questionnaire distributed to a selected group of colleagues internationally, and subsequent discussions with these colleagues.

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Tribochemical Mechanism of Borate of Triethanolamine in Water Solution by XPS

  • Du, Da-Chang;Kim, Seock-Sam;Suh, Chang-Min
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2001년도 제34회 추계학술대회 개최
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    • pp.374-379
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    • 2001
  • Tribochmical behaviors of a borate of triethanolamine in water solution were evaluated using a four-ball wear tester. X-ray photoelectron spectroscopy (XPS) was employed to study tribochemical species on worn scars of steel balls. Results show that a thick deposit layer was produced on the worn scars, which came from the decomposition of the borate. The surface film on the worn scars was mostly consisted with H$_{3}$BO$_{3}$, B$_{2}$O$_{3}$ and large amounts of ferricyanides.

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AES/XPS를 이용한 Au/V, Au/Ti 박막의 표면산화물 분석 (Characterization of Surface Oxides in Gold Thin Films with V- and Ti- underlays by AES and XPS)

  • Kim, Jin -Young
    • 한국진공학회지
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    • 제1권1호
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    • pp.100-105
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    • 1992
  • Au/V, Au/Ti의 이중구조 박막을 대기 중에서 $500^{\circ}C$에서 열처리한 후 Auger electron spectroscopy(AES)와 X-ray photoelectron spectroscepy(XPS)를 이용하여 분석 하였다. 열처리 과정에서 Au와 SiO2 기판 사이의 V-와 Ti- 하층박막은 Au 표면 위에 산화 물을 형성하였다. 산화물의 화학조성은 Au/V, Au/Ti 박막에서 V2O5와 TiO2로 각각 판명되었다.

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