• Title/Summary/Keyword: X-ray microscopy

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Synthesis of fiber-textured diamond films by MWPECVD (마이크로파 플라즈마 CVD법에 의한 섬유집합조직 다이아몬드막의 합성)

  • 박재철;김병상
    • Electrical & Electronic Materials
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    • v.9 no.5
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    • pp.470-475
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    • 1996
  • Fiber-textured diamond films have been deposited on scratched silicon(100) substrate by micro wave .plasma enhanced chemical vapor deposition at the condition of micro wave power : 950 W, pressure : 60 torr, H$_{2}$ gas flow rate : 50 sccm, CH$_{4}$ gas flow rate : 1.5 sccm, substrate temperature : about 900.deg. C and deposition time : 20 hours. The films were characterized by mean of scanning electron microscopy, Raman spectroscopy and X-ray analysis.

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Syntheses of Cu-In-Ga-Se/S nano particles and inks for solar cell applications

  • Jung, Duk-Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.295-295
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    • 2010
  • Nanoparticles of the compound semiconductor, Cu(In, Ga)Se2 (CIGS), were synthesized in solution under ambient pressure below $100^{\circ}C$ and characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), optical absorption spectroscopy and energy-dispersive X-ray (EDX) analyses. These materials have chalcopyrite crystal structures and the particle sizes less than 100 nm. Synthetic conditions were studied for the crystallized CIGS nanoparticles formation to prevent from side products of Cu2Se, Cu2-xSe, and CuSe etc. The single phase CIGS nanoparticles were applied to coating of thin films photovoltaic cells. The electro deposition of CIGS thin films is also a good non-vacuum technology and under investigation. In aqueous solutions, the different chemical compositions of CIGS thin films were obtained, depending on pH, concentration of starting materials and deposition potentials. The surface morphology of the prepared CIGS thin films depends on the complexing ligands to the solutions during the electrochemical deposition.

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Synthesis and Characterization of Zn(1-x)NixAl2O4 Spinels as a New Heterogeneous Catalyst of Biginelli's Reaction

  • Akika, Fatima-Zohra;Kihal, Nadjib;Habila, Tahir;Avramova, Ivalina;Suzer, Sefik;Pirotte, Bernard;Khelili, Smail
    • Bulletin of the Korean Chemical Society
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    • v.34 no.5
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    • pp.1445-1453
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    • 2013
  • $Zn_{(1-x)}Ni_xAl_2O_4$ (x = 0.0-1.0) spinels were prepared at $800^{\circ}C$ by co-precipitation method and characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The specific surface area was determined by BET. SEM image showed nano sized spherical particles. XPS confirmed the valence states of the metals, showing moderate Lewis character for the surface of materials. The powders were successfully used as new heterogeneous catalysts of Biginelli's reaction, a one-pot three-component reaction, leading to some dihydropyrimidinones (DHPMs). These new catalysts that produced good yields of DHPMs, were easily recovered by simple filtration and subsequently reused with persistent activity, and they are non-toxic and environmentally friendly. The optimum amount of catalyst is 20% by weight of benzaldehyde derivatives, while the doping amount has been found optimal for x = 0.1.

X-ray microscopy - image and structure

  • Youn hwa-shik;Chung jin-seok;Park, young-joon;Han sung-sik;Lee, jong-sig;Kuk Keon;Park, j. y.;Joo h. d.
    • Proceedings of the Korea Crystallographic Association Conference
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    • 2001.10a
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    • pp.1-64
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    • 2001
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Synthesis of Trimetallic (PtRu-Sn/VC, PtRu-Ni/VC) Catalysts by Radiation Induced Reduction for Direct Methanol Fuel Cell (DMFC) (방사선환원법을 이용한 직접메탄올연료전지용(DMFC) 삼성분계촉매(PtRu-Sn/VC, PtRu-Ni/VC)의 합성)

  • Kim, Sang Kyum;Park, Ji Yun;Hwang, Sun Choel;Lee, Do Kyun;Lee, Sang Heon;Rhee, Young Woo;Han, Moon Hee
    • Clean Technology
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    • v.19 no.3
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    • pp.320-326
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    • 2013
  • Nano-sized PtRu-Ni/VC and PtRu-Sn/VC electrocatalysts were synthesized by a one-step radiation-induced reduction (RIR) (30 kGy) process using distilled water as the solvent and Vulcan XC-72 as the supporting material. The obtained electrocatalysts were characterized by transmission electron microscopy (TEM), scanning electron microscope energy dispersive spectroscopic (SEM-EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. The catalytic efficiency of electrocatalysts was examined for oxygen reduction, MeOH oxidation and CO stripping decreased in the following order, Hydrogen stripping : PtRu-Sn/VC > PtRu-Ni/VC > PtRu/VC$^{(R)}$ (E-TEK). MeOH oxidation : PtRu-Sn/VC > PtRu-Ni/VC > PtRu/ VC$^{(R)}$ (E-TEK). Unit cell performance : PtRu-Sn/VC > PtRu-Ni/VC > PtRu/VC$^{(R)}$ (E-TEK) catalysts.

γ-ray Radiation Induced Synthesis and Characterization of α-Cobalt Hydroxide Nanoparticles

  • Kim, Sang-Wook;Kwon, Bob-Jin;Park, Jeong-Hoon;Hur, Min-Goo;Yang, Seung-Dae;Jung, Hyun
    • Bulletin of the Korean Chemical Society
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    • v.31 no.4
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    • pp.910-914
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    • 2010
  • A novel synthetic route has been developed to prepare $\alpha$-cobalt hydroxide with intercalated nitrate anions. It was successfully synthesized by $\gamma$-ray irradiation under simple conditions, i.e., air atmosphere, without base. Under $\gamma$-ray irradiation, it leads to the formation of layered cobalt hydroxynitrate compounds which have small crystalline size and have the role of a generator of hydroxyl anion. Structural and morphological characterizations were performed by using power X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and high resolution transmission electron microscopy (HR-TEM). The component and thermal stability of the sample were respectively measured by Fourier transform infrared (FT-IR) spectroscopy, elemental analysis, and thermal analyses, including thermogravimetry (TG) and differential thermal analysis (DTA).