• 제목/요약/키워드: XPS.

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Surface Characteristics of Copper Oxide Thin Films with Different Oxygen Ratio

  • 박주연;조준모;강용철
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.385-385
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    • 2010
  • Copper oxide thin films were deposited on the p-type Si(100) by r.f. magnetron sputtering as a function of different oxygen concentration. The deposited copper oxide thin films were investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM), spectroscopic ellipsometry (SE), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The SEM and SE data show that the thickness of the copper oxide films was in the range of 100-400 nm. AFM images show that the surface morphology was depended on the oxygen ratio. The crystal structure of copper oxide films was changed from metallic copper to copper oxide with increasing oxygen concentration. The oxidation states of Cu 2p and O 1s resulted from XPS were consistent with XRD results.

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Mn-Ce 복합 산화물에 의한 톨루엔 촉매 산화 (Toluene Catalytic Oxidation by Manganese-Cerium Bimetallic Catalysts)

  • 천태진;최성우;이창섭
    • 한국환경과학회지
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    • 제14권4호
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    • pp.427-433
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    • 2005
  • Activity of manganese oxide supported on ${\nu}-Al_2O_3$ was increased when cerium was added. Also, cerium-added manganese oxide on ${\nu}-Al_2O_3$ was more effective in oxidation of toluene than that without cerium. XRD result, it was observed that $MnO_2+CeO_2$ crystalline phases were present in the samples. For the used catalyst, a prominent feature has increased by XPS. TPR/TPO profiles of cerium-added manganese oxide on ${\nu}-Al_2O_3$ changed significantly increased at a lower temperature. The activity of $18.2 wt{\%}\;Mn+ 10.0 wt{\%}\;Ce/{\nu}-Al_2O_3$ increased at a lower temperature. The cerium added on the manganese catalysts has effects on the oxidation of toluene.

Synthesis and Characterization of Bis(N,N-dimethyl-2-aminomethylthiophenium)Tetrahalocuprate(Ⅱ)

  • 정찬규;김영인;최성낙
    • Bulletin of the Korean Chemical Society
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    • 제17권9호
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    • pp.845-849
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    • 1996
  • Bis(N,N-dimethyl-2-aminomethylthiophenium)tetrahalocuprate(Ⅱ) salt, (dmamtH)2CuCl4 and (dmamtH)2CuBr4 were prepared and characterized by spectroscopic (IR, UV-Vis, EPR, XPS), electrochemical method, and magnetic susceptibility measurement. The experimental results reveal that the compounds have pseudotetrahedral symmetry around copper(Ⅱ) site due to the steric hinderance of the bulky 2-(dimethylaminomethyl)thiophene in the complex. The N-H…Cl type hydrogen bonding is expected in (dmamtH)2CuCl4 from the XPS and IR data. Magnetic susceptibility data show that both of the compounds follow Curie-Weiss law in the range of 77-300 K with negative Weiss constant exhibiting antiferromagnetic interaction between copper(Ⅱ) ions in solid state.

Surface Structure of Blend Films of Styrene/Acrylonitrile Copolymer and Poly(methyl methacrylate)(PMMA) or Hydrolyzed PMMA

  • 이원기;K. Tanaka;A. Takahara;T. Kajiyama;하창식
    • Bulletin of the Korean Chemical Society
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    • 제18권9호
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    • pp.958-961
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    • 1997
  • The compatibility and the surface structure of blends of poly(styrene-co-acrylonitrile) (SAN) with either poly(methyl methacrylate) (PMMA) or hydrolyzed PMMA (H-PMMA) were studied in terms of film thickness, interaction, and surface free energy difference on the basis of X-ray photoelectron spectroscopy (XPS), attenuated total reflection Fourier transform IR spectroscopy and atomic force microscopy. The XPS measurement showed that the surface enrichment of (PMMA/SAN) blends with different AN contents of SAN and with different carboxyl acid contents of PMMA was dependent on the molecular interaction, the surface free energy difference between components and the sample preparation history. It was found that the compatibility of H-PMMA and SAN was reduced with increasing carboxyl acid content of PMMA.

XPS Studies of CO Adsorption on Polycrystalline Nickel Surface

  • Boo, Jin-Hyo;Ahn, Woon-Sun
    • Bulletin of the Korean Chemical Society
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    • 제9권6호
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    • pp.388-393
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    • 1988
  • The chemisorption of CO molecules on polycrystalline nickel surface has been studied by investigating the resulting chemisorbed species with the X-ray photoelectron spectroscopy at temperatures between 300K through 433K. It is found that the adsorbed CO molecules are dissociated by the simple C-O bond cleavage as well as by the disproportionation reaction at temperatures above 373K. The former type dissociation is more favored at low coverages and at elevated temperatures. The isotherms of CO chemisorption are obtained from the xps intensities of C 1s peaks, and then the activation energy of the dissociative adsorption is estimated as a function of the CO exposure. These activation energies are extrapolated to zero coverage to obtain the activation energy of chemisorption in which thermal C-O bond cleavage takes place. The value obtained is 38.1 kJ/mol.

Redox Property of Vanadium Oxide and Its Behavior in Cataltic Oxidation

  • 김영호;이호인
    • Bulletin of the Korean Chemical Society
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    • 제20권12호
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    • pp.1457-1463
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    • 1999
  • Structure and their redox property of the vanadium oxides prepared by decomposing NH₄VO₃ at various temperatures were studied by XRD, SEM, XPS, and temperature programmed reduction/temperature programmed oxidation (TPR/TPO) experiment. All TPR profiles have two sharp peaks in the temperature range 650-750℃, and the area ratio of the two sharp peaks changed from sample to sample. There were three redox steps in TPR/TPO profiles. The oxidation proceeded in the reverse order of the reduction process, and both the reactions proceeded via quite a stable intermediates. The changes of the morphological factor $(I_{(101)}/I_{(010)})$, the ratio of $O_{1S}$ peak area (O$_{1S}$( α)/O$_{1S}$( β)) in the XPS results, and the ratio of hydrogen consumption in TPR profiles with various vanadium oxides showed the distinct relationship between the structural property and their redox property of vanadium oxides. The change of the specific yield of phthalic anhydride with various vanadium oxides showed a very similar trend to those of the peak area ratio in TPR profiles, which meant that the first reduction step related to the partial oxidation of o-xylene on the vanadium oxide catalyst.

Synthesis and Characterization of Dichloro and Dibromo(2-(dimethylaminomethyl)thiophene) Copper(II) Complexes

  • Kim, Young-Inn;Choi, Sung-Nak;Ro, Chul-Un
    • Bulletin of the Korean Chemical Society
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    • 제15권7호
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    • pp.549-553
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    • 1994
  • The 2-(dimethylaminomethyl)thiophene (dmamt) complexes with copper(II) chloride and bromide were prepared and characterized by optical, EPR, XPS spectroscopies and magnetic susceptibility measurements. The low-energy absorption band above 850 nm and the relatively small EPR hyperfine coupling constant ($A_{//}{\simeq}$125 G) indicate the pseudotetrahedral site symmetry around copper(II) ion both in Cu(dmamt)$Cl_2$ and Cu(dmamt)$Br_2$ complexes. The higher satellite to main peak intensity of Cu $2P_{3/2}$ core electron binding energy in XPS spectra also supports the pseudotetrahedral geometry around the copper(II) ions having $CuNSX_2$ chromophores. The distortion from square-planar to pseudotetrahedral symmetry is likely to arise from the steric hindrance of the bulky dmamt ligand in the complex. Magnetic susceptibility study shows that these compounds follow Curie-Weiss law in the temperature range of 77-300 K with positive Weiss constant exhibiting the ferromagnetic interaction between copper(II) ions in solid state.

기판의 종류에 따른 SnO2 박막의 전기적인 특성 연구 (Study on the Electrical Characteristics of SnO2 on p-Type and n-Type Si Substrates)

  • 오데레사
    • 반도체디스플레이기술학회지
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    • 제16권2호
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    • pp.9-14
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    • 2017
  • $ISnO_2$ thin films were prepared on p-type and n-type Si substrates to research the interface characteristics between $SnO_2$ and substrate. After the annealing processes, the amorphous structure was formed at the interface to make a Schottky contact. The O 1s spectra showed the bond of 530.4 eV as an amorphous structure, and the Schottky contact. The analysis by the deconvoluted spectra was observed the drastic variation of oxygen vacancies at the amorphous structure because of the depletion layer is directly related to the oxygen vacancy. $SnO_2$ thin film changed the electrical properties depending on the characteristics of substrates. It was confirmed that it is useful to observe the Schottky contact's properties by complementary using the XPS analysis and I-V measurement.

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Preparation and Characterization of Chemically Modified Wood Flour Reinforced Phenol-formaldehyde Composites

  • Nam, Byeong-Uk;Mun, Jun-Yeong
    • 반도체디스플레이기술학회지
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    • 제17권1호
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    • pp.1-5
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    • 2018
  • Wood Polymer Composites(WPC) have attracted significant attention because of ecological and environmental concerns. However, the structure of Wood Flour containing many hydroxyl groups(-OH) reduces the interface adhesion to Phenol-formaldehyde(PF) and it decreases the mechanical properties of the PF/Wood Flour Composites. The present work involves the modification of Wood Flour using silanes reinforced with Phenol-formaldehyde to enhance the mechanical properties of the composites. The spectroscopic properties of the composites were analyzed using FT-IR, XPS(X-ray Photoelectron Spectroscopy) and the mechanical properties i.e., tensile strength, flexural strength and impact strength were studied. We confirmed the modification effect of silanes by spectroscopic analysis, and the mechanical properties of the composites using wood flour modified by silanes were significantly improved.

Si(111)$7{\times}7$ 표면에서 Mg 성장양상 연구 (Growth Mode Study of Mg on the Si(111)$7 {\times}7$ Surface)

  • 안기석;여환욱;이경원;이순보;조용국;박종윤
    • 한국진공학회지
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    • 제2권4호
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    • pp.399-403
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    • 1993
  • Si(111)7 $\times$ 7 위에 Mg를 흡착시켜 표면구조의 변화를 RHEED(Reflection High Energy Electron diffraction) 와 XPS(X-ray PhotoelectronSpectroscopy)를 이용하여 연구하였다. RT ~20$0^{\circ}C$까지의 기판온도에서 증착량의 증가에 따라 표면구조는 (7$\times$7)에서 diffused (1$\times$1) 그리고 (2 3 3 $\times$2√3√3-R30$^{\circ}$) 구조로 변화하였다. 또한, 기판온도를 증가시킴에 따라 (1$\times$1), three domain(3$\times$1) 등의 구조를 볼 수 있었고, 특히 , $450^{\circ}C$의 기판온도에서는 single domain (3$\times$1) 구조를 최초로 관측하였다. 이렇게 형성된 각 구조에 대한 Mg KLL과 Si2p의 XPS peak intensity ratio를 증착량의 증가에 따라 측정하여 각기 다른 온도에서의 Mg 성장에 대한 메카니즘을 제시하였다.

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