• Economic and Environmental Geology
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• v.32 no.6
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• pp.585-597
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• 1999

Plutomic rocks of the Mabogsan, located in the southestern part of the Koheung Eup are composed of granite gneiss, diorite, biotite grantie and granophyre. On the basis of Rb-Ba-Sr diagram, the diorires are plotted from granodiorite to quartz diortie, the biotite granites from granodiortie to anomalous granite and the granophyres in normal granite filed. The plutonic rocks tend to show the I-type characteristics in terns of ACF diagram, $K_2O-Na_2O$ diagram and $Al_2O_3/Na_2O+K_2O+CaO$ diafram, while have values of ilmenite series in magnetic subseptibility. The plutons could have formed in the tectonic environment of VAG+COLG+ORG based on the silica vs. trace element diagrams. Gold contents with major and trace elements have been determined for 21 granophyres, 13 biotite granites and 4 diorites are; (1) for the diorite, the rangs is 0.508~1.73 ppb with an average of 0.5ppb;(2) for the biotite granites, the range is 0.449~13.5ppb with an average of 3 ppb;(3)for the granphyres, the range is 0.508~23.1ppb with an average of 4.5ppb. The gold content of the studied plutons tends to increase from mafic to felsic rocks. Gold contents tend to show positive correlations with those of Ag and Zn, negative correlations with those of As, Ba and Rb. The copper contents of the plutons are comparatively high. Average copper contents of diorite, biotite granite and granophyre are 710ppm, 587ppm and 484ppm, respectively. The copper contents of the plutons tend to have good correlations with those of Ag, Bi and Pb.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.253-253
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• 2016

최근 세계적으로 대체 에너지는 중요한 이슈가 되고 있으며 그 중 열전 재료는 유망한 에너지 기술로서 주목 받고 있다. 특히 고 직접화 전자 소자의 발열 문제를 해결하기 위해, 소형화와 정밀 온도 제어가 가능한 박막형 열전 소자에 연구가 주목 받고 있다. 박막형 열전소자 중 산화물 반도체계에 대한 연구가 활발히 진행되고 있으며, 이러한 산화물 반도체계 중 In2O3는 BiTe, PbTe 등의 기존의 재료에 비해 독성이 낮을 뿐만 아니라 내 산화성 및 고온에서 열적 안정성이 우수하여 고온에서 적용 불가능한 금속계 열전 재료의 한계를 극복 할 수 있다는 장점을 가진다. 우수한 성능 가장 낮은 캐리어 밀도를 가지기 때문에 의 열전 재료는 높은 전기 전도도 및 제백 계수 그리고 낮은 열전도도 특성을 가져야만 한다. IZO:Sn(Zn 10 wt.%, Sn 800 ppm) 박막의 경우, 높은 전기 전도성을 가지면서 비정질 구조를 가진다. 이와 같이 비정질 구조를 가지는 박막 열전 재료는 격자에 의한 열 전도도가 낮기 때문에 결정질 구조에 비해 전체 열 전도도 값이 낮을 것으로 기대된다. 따라서 높은 전기 전도도를 가지면서 동시에 낮은 열 전도도를 가지게 되어 우수한 열전 특성을 가질 것이라 예상된다. 이러한 특성을 바탕으로 본 연구에서는 비정질 구조를 갖는 Zn와 미량의 Sn을 동시에 첨가한 In2O3박막의 전기적 특성및 열전 특성을 관찰하고자 한다. 본 연구에서는 magnetron sputtering법으로 IZO:Sn(Zn 10 wt.%, Sn 800 ppm) 타깃을 이용하여 기판 가열없이 DC Power 70 W, 작업 압력 0.7 Pa으로 SiO2 기판 위에 $400{\pm}20nm$ 두께의 박막을 증착하였다. 이러한 공정으로 만들어진 박막은 대기 중 후 열처리를 각각의 200, 300, 400, 500, $600^{\circ}C$ 온도에서 진행하였다. 박막의 미세 구조는 XRD를 통해 관찰하였다. 그리고 박막의 전기적 특성은 Hall effect measurement을 통해 측정하였고, 열전 특성은 Seebeck 상수의 측정을 통하여 평가하였다. XRD 확인 결과 RT에서 증착한 박막과 후 열처리 200, 300, 400, $500^{\circ}C$ 결과 비정질 구조를 보였고, 후열처리 $600^{\circ}C$에서는 결정의 회절 피크를 보였다. 전기적 특성의 경우, 후 열처리 온도가 증가함에 따라 전기 전도도는 감소한다. 이는 공기중의 산소가 박막에 침투하여 oxygen vacancy를 막아 캐리어 밀도가 감소한것에 기인 된 것으로 판단된다. 열전 특성의 경우 제백상수는 후 열처리 $600^{\circ}C$에서 가장 높은 제백상수를 나타낸다. 제백 상수는 수식에 따라 캐리어 밀도의 -2/3승에 비례하게 된다. 수식에 따라 후 열처리 $600^{\circ}C$에서 가장 낮은 캐리어 밀도를 가지기 때문에 가장 높은 제백 상수를 가지게 된다. 열전 성능 척도인 Power factor는 제백 상수의 제곱과 전기전도도의 곱으로 나타내는데, 후 열처리 $200^{\circ}C$에서 가장 높은 Power factor를 보인다. 이는 캐리어 밀도 감소에 따라 전기 전도도는 감소하였지만 이로 인해 제백상수는 증가하였고, 또한 캐리어 밀도 감소에 따라 이온화 불순물 산란의 감소에 의해 이동도의 증가에 의한 것으로 판단된다. 박막의 경우 기판의 영향으로 인해 열 전도도 측정이 어려워 열전 성능 지수(ZT)를 계산을 할 수 없지만, 마그네트론 스퍼터링법으로 증착한 IZO:Sn 박막은 비정질 구조를 가지므로 격자진동에 의한 열 전도도가 낮아 전체 열 전도도가 결정질에 비해 낮을 것이며 이는 높은 열전 성능 지수를 가질 것으로 예상된다.

• Economic and Environmental Geology
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• v.47 no.4
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• pp.363-379
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• 2014

The Haenam Pb-Zn skarn deposit is located at the Hwawon peninsula in the southwestern part of the Ogcheon Metamorphic Belt. The deposit is developed along the contact between limestone of the Ogcheon group and Cretaceous quartz porphyry. Petrography of ore samples, chemical composition of skarn and ore minerals, and geochemistry of the related igneous rocks were investigated to understand the characteristics of the skarn mineralization. Skarn zonation consists of garnet${\pm}$pyroxene${\pm}$calcite${\pm}$quartz zone, pyroxene+garnet+quartz${\pm}$calcite zone, calcite+pyroxene${\pm}$garnet zone, quartz+calcite${\pm}$pyroxene zone, and calcite${\pm}$chlorite zone in succession toward carbonate rock. Garnet commonly shows zonal texture comprised of andradite and grossular. Pyroxene varies from Mn-hedenbergite to diopside as away from the intrusive rock. Chalcopyrite occurs as major ore mineral near the intrusive rock, and sphalerite and galena tend to increase as going away. Electron probe microanalyses revealed that FeS contents of sphalerite become decreased from 5.17 mole % for garnet${\pm}$pyroxene${\pm}$calcite${\pm}$quartz zone to 2.93 mole %, and to 0.40 mole % for calcite+pyroxene${\pm}$garnet zone, gradually. Ag and Bi contents also decreased from 0.72 wt.% and 1.62 wt.% to <0.01 wt.% and 0.11 wt.%, respectively. Thus, the Haenam deposit shows systematic variation of species and chemical compositions of ore minerals with skarn zoned texture. The related intrusive rock, quartz porphyry, expresses more differentiated characteristics than Zn-skarn deposit of Meinert(1995), and has relatively high$SiO_2$ concentration of 72.76~75.38 wt.% and shows geochemical features classified as calc-alkaline, peraluminous igneous rock and volcanic arc tectonic setting.

• Journal of the Korean institute of surface engineering
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• v.47 no.2
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• pp.81-85
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• 2014

Ga doped ZnO (GZO)/Al bi-layered films were deposited on the glass substrate by RF and DC magnetron sputtering and then vacuum annealed at different temperatures of 100, 200 and $300^{\circ}C$ for 30 minutes to consider the effects of annealing temperature on the structural, electrical and optical properties of the films. For all depositions, the thicknesses of the GZO and Al films were kept constant at 95 and 5 nm, respectively, by controlling the deposition time. As-deposited GZO/Al bi-layered films showed a relatively low optical transmittance of 62%, while the films annealed at $300^{\circ}C$ showed a higher transmittance of 81%, compared to the other films. In addition, the electrical resistivity of the films was influenced by annealing temperature and the lowest resistivity of $9.8{\times}10^{-4}{\Omega}cm$ was observed in the films annealed at $300^{\circ}C$. Due to the increased carrier mobility, 2.35 $cm^2V^{-1}S^{-1}$ of the films. From the experimental results, it can be concluded that increasing the annealing temperature enhanced the optical and electrical properties of the GZO/Al films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.230-231
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• 2009

펄스 레이저 층착법 (이하 PLD)은 다성분계 산화물 박막 또는 다층구조의 박막 제작에 매우 유용한 기술이다. 본 실험에서는 KrF 엑시머 레이저를 이용하여 pt on Si 기판 위에 150nm 두께의 $Bi_{1.5}ZnNb_{1.5}O_7$(이하 BZN) 박막을 다양한 기판온도에서 제작하였다. XRD를 이용하여 BZN 박막의 구조적 특성을 분석하였고, 박막을 MIM 구조로 제작하여 유정적 특성을 측정하였다. 제조한 BZN 박막은 $500^{\circ}C$ 이상에서 결정질을, $500^{\circ}C$ 이하의 온도에서는 비정질 특성을 보였다. 유전 특성은 100 - 400$^{\circ}C$ 영역에서는 온도가 증가함에 따라 졸은 특성을 나타내었고, $500^{\circ}C$에서부터는 감소하였다. 증착 온도 $400^{\circ}C$에서 제작한 BZN 박막이 유전상수가 67.8, 유전 손실이 0.006으로 가장 줄은 유전특성을 나타내었다.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.794-798
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• 1992

We present an optical Voltage and current sensor using $BSO(Bi_{12}SiO_{20})$ monocrystal. The voltage and current sensor consist of PBS(Polarizing Beam Splitter), 1/4 wavelength plate, ZnSe, Selfoc lens, LED, and PIN-PD etc. Magnetic core was made using permalloy for applying magnetic field to current sensor effectively. Current was measured from 100 to 1,600 ampere and accuracy was about ${\pm}$5%. The accuracy could be improved to ${\pm}$l% after reducing the nonlinear property of BSO crystal using our own program in PC (IBM286). We noticed that these data were not influenced by 154,000 voltage at all. Applied voltage was reduced to 1/20 using capacitors. And experiment was carried out up to 450V of the reduced voltage. The data fran optical voltage sensor was similar to that from conventional voltage sensor. The accuracy of the data was within about ${\pm}$1%.

• Journal of the Korean Society for Heat Treatment
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• v.29 no.6
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• pp.272-276
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• 2016

Al doped ZnO (AZO) single layer and AZO/Ag bi-layered films were deposited on the glass substrates by radio frequency and direct current magnetron sputtering and then the effect of Ag buffer layer on the electrical and optical properties of the films was investigated. The thicknesses of AZO upper layer was kept as 100 nm, while Ag buffer layer was varied from 5 to 15 nm. The observed results mean that opto-electrical properties of the AZO films is influenced with Ag buffer layer and AZO film with 10 nm thick Ag buffer layer show the higher opto-electrical performance than that of the AZO single layer film prepared in this study.

• Economic and Environmental Geology
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• v.24 no.2
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• pp.131-150
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• 1991

The Weolseong diatreme was temporally and spatially related to the intrusion of the Gadaeri granite, and was -mineralized by meteoric aqueous fluids. In the Nokdong As-Zn deposit, pyrite, aresenopyrite and sphalerite are the most abundant sulfide minerals. They are associated with minor amount of magnetite, pyrrhotite, chalcopyrite and cassiterite, and trace amounts of Pb-Sb-Bi-Ag sulphosalts. The AsZn ore probably occurred at about $350^{\circ}C$ according to fluid inclusion and compositional data estimated from the arsenic content of arsenopyrite and iron content of sphalerite intergrown with pyrrhotite + chalcopyrite + cubanite. Heating studies of fluid inclusions in quartz indicate a temperature range between 180 and $360^{\circ}C$, and freezing data indicate a salinity range from 0.8 to 4.1 eq.wt % NaCl. The coexisting assemblage pyrite + pyrrhotite + arsenopyrite suggests that $H_2S$ was the dominate reduced sulfur species, and defines fluid parameter thus: $10^{-34.5}$ < ${\alpha}_{S_2}$ < $10^{-33}$, $10^{-11}$ < $f_{S_2}$ < $10^{-8}$, -2.4 < ${\alpha}_{S_2}$ < -1.6 atm and pH= 5.2 (sericte stable) at $300^{\circ}C$. The sulfur isotope values ranged from 1.8 to 5.5% and indicate that the sulfur in the sulfides is of magmatic in origin. The carbon isotope values range from -7.8 to -11.6%, and the oxygen isotope values from the carbonates in mineralized wall rock range from 2 to 11.4%. The oxygen isotope compositions of water coexisting with calcite require an input of meteoric water. The geochemical data indicate that the ore-forming fluid probably was generated by a variety of mechanisms, including deep circulation of meteoric water driven by magmatic heat, with possible input of magniatic water and ore component.

• Journal of the Korean Chemical Society
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• v.12 no.1
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• pp.4-11
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• 1968

With the selected emulsifiers for the emulsion polymerization of methyl methacrylate, the HLB of the emulsifier in the reaction system has been studied on the effect of the ratio of tetra sodium-N-(1,2-dicarboxy ethyl)-N-octadecyl sulfosuccinamate(Aerosol 22) to polyethylene glycol nonyl phenyl ether (Noigen EA 160), and also sodium lauryl sulfate(Quolac EX-UB), Disodium-N-octadecyl sulfosuccinamate (Aerosol 18) and Aerosol 22 as emulsifiers having various hydrophilic groups in the molecules have been studied. Results are as follows; 1) The viscosity of the emulsions and the molecular weight of the polymers have maximum values at a constant HLB value of emulsifiers, but their stabilities show minimum point at the value with the titration with the three kinds of mono, bi, tri-valent electrolytes. These results are agreed on the theory of Greth & Wilson in which the properties of polymer emulsions depend upon the HLB system of emulsifiers. 2) The viscosity of the emulsions and the molecular weights of the produced polymers increase more in the case of blending of Aerosol 22 to Noigen EA-160 than of the separate using. 3) The coagulation effects of the divalent electrolytes($ex,\;Ca^{++},\;Zn^{++}$) are contrast to the effects of monovalent($ex,\;Na^+$) and trivalent($ex,\;Al^{+++}$) in the emulsions with Aerosol 18 or Aerosol 22 which have more than two hydrophilic groups. It seems that the stability of the O/W emulsions by electrolytes is directly related to the parameters of surface physical chemistry such as surface geometry of surface chemical constitution of polymer particles.

• Korean Journal of Materials Research
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• v.29 no.3
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• pp.175-182
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• 2019

This study examines paraelectric $Bi_{1.5}Zn_{1.0}Nb_{1.5}O_7$ (BZN), which has no hysteresis and high dielectric strength, for energy density capacitor applications. To increase the breakdown dielectric strength of the BZN film further, poly(vinylidene fluoride) BZN-PVDF composite film is fabricated by aerosol deposition. The volume ratio of each composition is calculated using dielectric constant of each composition, and we find that it was 12:88 vol% (BZN:PVDF). To modulate the structure and dielectric properties of the ferroelectric polymer PVDF, the composite film is heat-treated at $200^{\circ}C$ for 5 and 30 minutes following quenching. The amount of ${\alpha}-phase$ in the PVDF increases with an increasing annealing time, which in turn decreases the dielectric constant and dielectric loss. The breakdown dielectric strength of the BZN film increases by mixing PVDF. However, the breakdown field decreases with an increasing annealing time. The BZN-PVDF composite film has the energy density of $4.9J/cm^3$, which is larger than that of the pure BZN film of $3.6J/cm^3$.