• Title/Summary/Keyword: %24MgGa_2Se_4%24

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Fabrication of Semiconductor Devices and Its Characteristics for $MgGa_{2-x}In_xSe_4$ Single Crystals ($MgGa_{2-x}In_xSe_4$ 단결정을 이용한 광전반도체소자 제작과 그 특성 연구)

  • 김형곤;김화택
    • Journal of the Korean Vacuum Society
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    • v.2 no.1
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    • pp.65-72
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    • 1993
  • MgGa2-xInxSe4 single crystal을 bridgman technique로 성장시켰다. 성장된 단결정은 rhombohedral 구조를 가지고 있었으며, lattice constant는 a=3.950~4.070$\AA$, c=38.89~39.50$\AA$으로 주어졌고, 높은 photoconductivity를 가지고 있었다. 이 단결정의 energy gap은 2.20~1.90eV이었고, photoconductivity spectrum에 peak의 energy는 2.31~2.01eV로 주어졌으며, photoconductivity의 time constant는 0.24~0.34sec로 주어졌다.

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Mineralogy and Geochemistry of Iron Hydroxides in the Stream of Abandoned Gold Mine in Kwangyang, Korea (광양 폐금광 수계에 형성된 철수산화물에 대한 광물학적 및 지구화학적 특성)

  • Park, Cheon-Young;Jeoung, Yeon-Joong;Kim, Seoung-Ku
    • Journal of the Korean earth science society
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    • v.22 no.3
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    • pp.208-222
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    • 2001
  • Geochemical investigations on suspended amorphous iron oxide material from the Kwangyang gold mine and its surrounding area, Cheonnam, Korea have been carried out. The sediments samples were collected from 11 location along Kwangyang mine area and were air dried and sieved to -80 mesh. These samples consist mainly of iron, silicon and alumina. The Fe$_2$O$_3$ contents ranges from 17.9 wt.% to 72.3 wt.%. The content of Fe$_2$O$_3$ increase with decreasing Si, Al, Mg, Na, K, Mn, and Ti, whereas the contents of Te, Au, Ga, Bi, Cd, Hg, Sb, and Se increase in the amorphous stream sediments. Amorphous stream sediments have been severely enriched for As (up to 54.9 ppm), Bi (up to 3.77 ppm), Cd (up to 3.65 ppm), Hg (up to 64 ppm), Sb (up to 10.1 ppm), Cu (up to 37.1 ppm), Mo (up to 8.86 ppm), Pb (up to 9.45 ppm) and Zn (up to 29.7 ppm). At the upstream site, the Au content (up to 4.4 ppm) in the amorphous stream sediments are relatively high but those contents decrease with distance of mine location. The content of Ag (up to 0.24 ppm) were low in upstream site but those contents increase significantly in the downstream sites. The X-ray diffraction patterns of the samples have virtually no sharp and discrete peaks, indicating that some samples are amorphous or poorly-ordered. The quartz, goethite, kaolinite and illite were associated in amorphous stream sediments. The infrared spectra for amorphous stream sediments show major absorption bands due to OH stretching, adsorbed molecular water, sulfate and Fe-O stretching, respectively.

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