• Economic and Environmental Geology
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• v.23 no.1
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• pp.1-9
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• 1990

A couple of Au-Ag-bearing epithermal quartz veins of Cretaceous(87.9Ma) in age are developed in the Cretaceous(112Ma) granodiorite batholith which was emplaced in Mesozoic Baegyari sedimentary formation. Au minerals consist mostly of electrum with a 54.2-61.9 wt% Au and are closely associated with sulfide minerals including pyrite, chalcopyrite, pyrrhotite, galena and sphalerite. Homogenization temperatures of fluid inclusions in quartz, fluorite and calcite are $196-368^{\circ}C$ (avg. $240^{\circ}C$), $74-176^{\circ}C$ (avg. $115^{\circ}C$) and $75-200^{\circ}C$ (avg. $119^{\circ}C$) respectively. Sulfur isotopic compositions( +5- +8‰) of ore sulfides indicate a deep-seated sulfur origin. Oxygen isotope compositions of different stages of quartz vary from +5.6 to +9.3‰ and calculated ${\delta}^{18}O$ values of ore fluid at $250^{\circ}C$ range from -3.2 to +0.4‰, reflecting an isotopically evolved ore fluid mixed with a $^{18}O$ depleted meteoric water under the variable mixing ratios between hydrothermal and meteoric waters. Isotopic data of calcite minerals support the above conclusions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.823-827
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• 2001

The AgInS$_2$epilayers with chalcopyrite structure grown by using a hot-wall epitaxy (HWE) method have been confirmed to be a high quality crystal. From the optical absorption measurement, the temperature dependence of the energy band gap on the AgInS$_2$/GaAs was derived as the Varshni's relation of Eg(T)=2.1365 eV-(9.89${\times}$10$\^$-3/ eV)T$^2$/(2930+T). After the as-grown AgInS$_2$/GaAs was annealed in Ag-,S-, and In-atmosphere, the origin of point defects of the AgInS$_2$/GaAs has been investigated by using the photoluminescence (PL) at 10 K. The native defects of V$\_$Ag/, V$\_$s/, Ag$\_$int/, and S$\_$int/ obtained from PL measurement were classified to donors or acceptors type. And, we concluded that the heat-treatment in the S-atmosphere converted the AgInS$_2$/GaAs to optical p-type. Also, we confirmed that the In in the AgInS$_2$/GaAs did net from the native defects because the In in AgInS$_2$did exist as the form of stable bonds.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.2
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• pp.296-302
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• 1994

Polycrystalline CuInSeS12T thin were prepared by depositing Cu/In layer, which was sequentially sputtered varying the Cu/(Cu+In) mole ratio, on glass substrate and selenizing with selenium metal vapor in a nitrogen atmosphere. Compositional and structural, characterization was carried out by X-ray diffraction (XRD), wavelength-dispersive spectroscopy(WDS), and scanning electron microscope(SEM). Electrical characterization was carried out by the measurements of Hall effect, electrical resistivity. Large indium loss occurs in early stage of the selenization process. The selenized films which had mole ratios larger than 0.28 have chalcopyrite CuInSeS12T phase and these that had less mole ratios have sphalerite phase. The selenized films containing CuS1xTSe phase have Cu-rich CuInSeS12T phase and these that did not contain CuS1xTSe have In-rich CuInSeS12T phase. By optimizing the sputtering conditions,it is possible to fabricate CuInSeS12T thin films which have little secondary phases and an appropriate hole concentration (10S015T ~ 10S016TcmS0-3T) for solar cells.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.109-112
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• 1995

CuInS$_2$thin film was prepared by heat treatment at vacuum 10$\^$-3/ Torr of S/In/Cu stacked layer which was deposited by sequential. And so, the polycrystalline CuInS$_2$with chalcopyrite structure was well made at heat treatment temperature of 250$^{\circ}C$ and heat treatment time of 60 min. Single phase of CuInS$_2$was formed from Cu/In composition ratio of 0.84 to 1.3. p conduction type of CuInS$_2$thin film was appeared from Cu/In competition ratio of 0.99. The highest resistivity of CuInS$_2$with p type was 1.608${\times}$10$^2$$\Omega$cm at Cu/In composition ratio of 0.99 and The lowest resistivity was 5.587${\times}$10$\^$-2/$\Omega$cm at Cu/In composition ratio of 1.3.

• Korean Journal of Materials Research
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• v.14 no.10
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• pp.737-742
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• 2004

$CuInSe_2$ (CIS) nanoparticles of chalcopyrite structure were directly synthesized by a solvothemal method in an autoclave with diethylamine as a solvent. A morphology change of the nanoparticles was observed as a function of reaction temperatures and times. Dense rod-type CIS nanoparticles with width of $5\sim10mm$ and length in the range of 30-80 nm were obtained at $180^{\circ}C$ for 36 hrs whereas spherical particles with diameter in the range of 5-10 nm were observed at $250^{\circ}C$ for 36 hrs. The formation of the rod-like nanoparticles in diethylamine, without double N-chelation, was explained by the Solution-Liquid-Solid (SLS) mechanism.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.4
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• pp.196-201
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• 2002

The $AgInS_{2}$ epilayers with a chalcopyrite structure grown using a hot-wall epitaxy method have been confirmed to be a high quality crystal. From the optical absorption measurements, a temperature dependence of the energy band gap on $AgInS_{2}/GaAs$ was found to be $Eg(T)=2.1365eV-(9.89{\times}10^{-3}eV)T^{2}/(2930+T)$. After the as-grown $AgInS_{2}/GaAs$ was annealed in Ag-, S-, and In-atmospheres, the origin of point defects of $AgInS_{2}/GaAs$ has been investigated by using photoluminescence measurements at 10 K. The native defects of $V_{Ag},\;V_{S},\;Ag_{int}$ and $S_{int}$ obtained from photoluminescence measurements were classified as donors or accepters. It was concluded that the heat-treatment in the S-atmosphere converted $AgInS_{2}/GaAs$ to an optical p-type. Also, it was confirmed that In in $AgInS_{2}/GaAs$ did not form the native defects because In in $AgInS_{2}$ did exist in the stable form.

• Bulletin of the Korean Chemical Society
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• v.24 no.2
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• pp.209-218
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• 2003

Ecosystems in the Keweenaw Peninsula region of Lake Superior, USA, were disturbed by over 500 million tons of copper-rich mine tailings during the period 1850-1968. Metals leaching from these mine residues have had dramatic effects on the ecosystems. Vast acreages of exposed tailings that are over 100 years old remain unvegetated because of the combination of metal toxicity, absence of nutrients, and temperature and water stress. Therefore, it is important to characterize and fractionate solid copper phases for assessing labile forms of copper in soils and sediments contaminated by the mining wastes. X-ray diffraction analyses indicate that calcite, quartz, hematite, orthoclase, and sanidine minerals are present as major minerals, whereas cuprite,tenorite, malachite, and chalcopyrite might be present as copper minerals in the mining wastes. Sequential extraction technique revealed that carbonate and oxide fractions were the largest pools of copper (ca. 50-80%) in lakeshore and wetland stamp sands whereas the organic matter fraction was the largest reservoir (ca. 32%) in the lake sediments. The concentrations of iron and copper were inversely correlated in the oxide fraction suggesting that copper may occur as a surface coating on iron oxides. As particle size and water contents decrease, the percent of the copper bound to the labile carbonate fraction increases.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4332-4336
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• 2011

The chalcopyrite-type $CuInSe_2$ is a remarkable material for thin film solar cells owing to its electronic structure and optical response. Single-phase sphere-like $CuInSe_2$ nanocrystallite particles were prepared by a facile noninjection method with triethanolamine as the complexing agent and the solvent simultaneously. The period of the reaction was the key to form single-phase $CuInSe_2$ nanocrystals at $240^{\circ}C$. TEM, XRD, XPS, EDX investigations were performed to characterize the morphology and the detailed structure of as-synthesized $CuInSe_2$ nanocrystals. All of the analysis results proved that the synthesized nanocrystals were pure phase and close to the stoichiometric ratio rather than a simple mixture. The band gap of the obtained $CuInSe_2$ nanocrystals was $1.03{\pm}0.03$ eV.

• Journal of Magnetics
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• v.20 no.4
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• pp.331-335
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• 2015

The ferromagnetic and electronic structure for the $Al_xGa_{1-x}P$ and Mn-doped $AlGaP_2$ was studied by using the self-consistent full-potential linear muffin-tin orbital method. The lattice parameters of un-doped $Al_xGa_{1-x}P$ (x = 0.25, 0.5, and 0.75) were optimized. The band-structure and the density of states of Mn-doped $AlGaP_2$ with or without the vacancy were investigated in detail. The P-3p states at the Fermi level dominate rather than the other states. Thus a strong interaction between the Mn-3d and P-3p states is formed. The ferromagnetic ordering of dopant Mn with high magnetic moment is induced due to the (Mn-3d)-(P-3p)-(Mn-3d) hybridization, which is attributed by the partially filled P-3p bands. The holes are mediated with keeping their 3d-characters, therefore the ferromagnetic state is stabilized by this double-exchange mechanism.

• Economic and Environmental Geology
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• v.20 no.1
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• pp.61-75
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• 1987

The Daejang mine is one of the representatives of Cu-Pb-Zn-(Ag) vein deposit related genetically to late Cretaceous granitoid in Korea. Sericite from an alteration halo of the mine yielded a K-Ar date of $95{\pm}3.5Ma$. Based on macrostructures of vein filling, three major mineralization stages (I, II and III) are distinguished by tectonic breaks. Major ore constituents are arsenopyrite, pyrite, pyrrhotite, sphalerite, chalcopyrite, galena, boulangerite, with small amounts of Ag-bearing tetrahedrite, pyrargyrite, native bismuth, marcasite, siderite, ankerite, gudmundite and calcite. Characteristic feature of each mineralization stage and compositional variation of sphalerite and arsenopyrite are discussed in relation to the genetic environments. The FeS contents of sphalerites are 20.5~14.9 mole % in stage I, 17.9~11.9 mole % in stage IIA, 17.0~9.2 mole % in stage IIB, and 6.9~4.7 mole % in stage III. Their results are indicative of decreasing FeS contents during mineralization process in sphalerite coexisting with sulfur-rich sulfide assemblages, such as monoclinic pyrrhotite and pyrite, and is agreement with the conclusions shown by Scott and Kissin(1973). The composition of arsenopyrite decrease also in As content from stage I to stage III, and the compositional variation correlate with position of the associated minerals in the paragenesis. Temperature and pressure of the mineralization are determined as $250{\sim}430^{\circ}C$ and 4.0~0.3kb respectively, based on the chemistry of the minerals.