• Title/Summary/Keyword: $SeO_3$

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Synthesis of Amide from Thioamide by Treatment of SiO2 or SeO2

  • Jung, Dai-Il;Lee, Jin-A;Lee, Do-Hun;Kwak, Moon-Jung;Lee, Soo-Jin;Park, You-Mi;Park, Soon-Kyu;Kim, Hyun-Sook
    • Journal of Life Science
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    • v.9 no.2
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    • pp.49-51
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    • 1999
  • Reactions of 2,6-Lutidine with active methyl group anilines in the presence of sulfur gave the desired thioamides 1. Reactions of synthesized thioamides 1 with sulfur and SiO2 or SeO2 gave the corresponding amide 2. We now report conversion of thioamide to amide by using oxidzing inorganic reagant

Calculation of the Dipole Moments for the Coordination Compounds with Organic Ligands such as $(C_2H_5)_2SO,\;(C_6H_5)_2SO,\;(C_6H_5)_2SeO,\;(C_6H_5)_3AsO,\;(C_6H_5)_3PBCl_3,\;and\;(C_2H_5)_2OZrCl_4$

  • Ahn, Sang-Woon;Kim, Hyung-Doo;Park, Eui-Suh
    • Bulletin of the Korean Chemical Society
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    • v.7 no.2
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    • pp.129-136
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    • 1986
  • The dipole moments for some coordination compounds with organic ligands have been calculated adopting the molecuar orbitals obtained from EHT calculation with modified technique. Adopting the molecular orbitals with the modified technique, the calculated dipole moments for all the coordination compounds with organic ligands give closer agreements with experimental values than those using the molecular orbitals obtained from EHT calculation. The calculated dipole moments suggest that $(C_2H_5)_2SO,\;(C_6H_5)_2SO,\;and\;(C_6H_5)_2SeO$ may have a trigonal planar structure and $(C_6H_5)_3AsO,\;and\;(C_6H_5)_3PBCl_3$ a square planar structure and $(C_2H_5)_2OZrCl_4$ may be distorted markedly. This work may also indicate that the modified technique is superior to the EHT calculation as far as the dipole moment calculation is concerned.

Electrochemical Deposition of $CdSe_xTe_{1-x}$ Thin Films and Analysis of Their Crystal Structure (전착법에 의한 $CdSe_xTe_{1-x}$ 박막의 제작과 결정구조 분석)

  • Kim, Young-You;Lee, Ki-Seon
    • Solar Energy
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    • v.10 no.3
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    • pp.53-59
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    • 1990
  • [ $CdSe_xTe_{1-x}$ ] ($0{\le}x{\le}1$) thin films were deposited cathodically on Ti substrates in aqueous sulfric acid solution containing 1M $CdSO_4$ and 1mM$(TeO_2+SeO_2)$. The limiting current was observed in deposition potential ranging from -0.20 to -0.65 vs.Ag/AgCl ; although its value has changed a little depending on the mole ratio x, the limiting current was almost constant in deposition potential of -0.45V in spite of the change of mole ratio x. The crystal structure of the $CdSe_xTe_{1-x}$ thin films was cubic zinc-blonde in the range of mole ratio $x=0{\sim}0.8$, and hexagonal wurtzite in the mole ratio x=1 When the mole ratio changed from x=0 to x=0.8, diffraction peaks was shifted to the larger diffraction angle.

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Thickness dependency of MAHONOS ($Metal/Al_2O_3/HfO_2/SiO_2/Si_3N_4/SiO_2/Si$) charge trap flash memory

  • O, Se-Man;Yu, Hui-Uk;Kim, Min-Su;Lee, Yeong-Hui;Jeong, Hong-Bae;Jo, Won-Ju
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.34-34
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    • 2009
  • The electrical characteristics of tunnel barrier engineered charge trap flash (TBE-CTF) memory with $SiO_2/Si_3N_4/SiO_2/Si$ engineered tunnel barrier, $HfO_2$ charge trap layer and $Al_2O_3$ blocking oxide layer (MAHONOS) were investigated. The energy bad diagram was designed by using the quantum-mechanical tunnel model (QM) and then the CTF memory devices were fabricated. As a result, the best thickness combination of MAHONOS is confirmed. Moreover, not enhanced P/E speed (Program: about $10^6$ times) (Erase: about $10^4$ times) but also enhanced retention and endurance characteristics are represented.

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Low temperature synthesis of $LaNiO_3$ crystalline phase via oxide powder technology (산화물 합성법에 의한 $LaNiO_3$ 결정상의 저온합성)

  • Kim, Dae-Young;Jeong, Jae-Hoon;Son, Se-Mo;Kim, Kang-Eun;Chung, Su-Tae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05a
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    • pp.218-223
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    • 2002
  • Low temperature synthesis of $LaNiO_3$ crystalline phase composited from mixtures of $La_2O_3$ and NiO via the ball mill and mechanochemical process were investigated. By the ball mill, 20% of $LaNiO_3$ crystalline phase was formed in the samples sintered at $900^{\circ}C$ due to the lack of reactivity of NiO. However, the mechanochemical process yielded about 93% of $LaNiO_3$ crystalline phase in room temperature.

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Preparation and characterization of CdSe nanoparticles through a chemical route (화학적 방법에 의한 CdSe 나노입자의 제조 및 특성)

  • Sung MyoungSeok;Lee YoonBok;Kim HyongKuk;Kim Yangdo
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.164-167
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    • 2005
  • Diethnao lamine(DEA)을 함유한 수용액을 ultrasonic irradiation에 의하여 CdSe 반도체 양자점을 제조하였고 제조된 양자점의 광학적 성질을 조사하였다. CdSe 양자점 제조시 카드뮴을 제공하는 물질로는 $CdCl_2{\cdot}2.5H_2O$를, 셀레늄을 제공하는 물질로는 Se powders를 $Na_2SO_3$ 수용액에서 $90^{\circ}C$, 1시간 reflux 한 $Na_2SeSO_3$를 사용하였다. 상온에서 고출력의 초음파 조사 (20kHz, $60Wcm^{-2}$)에 의한 CdSe반도체 양자점을 얻기 위하여 초음파 시간을 각각 변화시켰고 XRD, UV-Vis, PL, TEM, XPS론 사용하여 CdSe 나노 입자의 특성을 분석하였다. CdSe흡수스펙트럼을 분석한 결과 450-640nm범위에서 양자점 형성에 의한 엑시톤 흡수 봉우리가 관찰되었음을 확인할 수 있었다. 또한 초음파 조사시간을 5분, 15분, 30분으로 증가시킴에 따라 505nm, 525nm, 545nm로서 엑시톤의 흡수 파장이 장파장 쪽으로 이동함을 확인함으로써 초음파 조사시간에 따라 CdSe 양자점의 크기를 변화시킬 수 있음을 알 수 있었다.

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