In order to replace 14K white gold alloys, the properties of 5K white gold alloys (Au20-Ag80) were investigated by changing the contents of In (0.0-10.0 wt%). Energy dispersive X-ray spectroscopy (EDS) was used to determine the precise content of alloys. Properties of the alloys such as hardness, melting point, color difference, and corrosion resistance were determined using Vickers Hardness test, TGA-DTA, UV-VIS-NIR-colorimetry, and salt-spray tests, respectively. Wetting angle analysis was performed to determine the wettability of the alloys on plaster. The results of the EDS analysis confirmed that the Au-Ag-In alloys had been fabricated with the intended composition. The results of the Vickers hardness test revealed that each Au-Ag-In alloy had higher mechanical hardness than that of 14K white gold. TGA-DTA analysis showed that the melting point decreased with an increase in the In content. In particular, the alloy containing 10.0 wt% In showed a lower melting temperature (> 70 °C) than the other alloys, which implied that alloys containing 10.0 wt% In can be used as soldering materials for Au-Ag-In alloys. Color difference analysis also revealed that all the Au-Ag-In alloys showed a color difference of less than 6.51 with respect to 14K white gold, which implied a white metallic color. A 72-h salt-spray test confirmed that the Au-Ag- In alloys showed better corrosion resistance than 14K white gold alloys. All Au-Ag-In alloys showed wetting angle similar to that of 14K white gold alloys. It was observed that the 10.0 wt% In alloy had a very small wetting angle, further confirming it as a good soldering material for white metals. Our results show that white 5K Au-Ag-In alloys with appropriate properties might be successful substitutes for 14K white gold alloys.

We report plasma-assisted molecular beam epitaxy of InXGa1-XN films on c-plane sapphire substrates. Prior to thegrowth of InXGa1-XN films, GaN film was grown on the nitride c-plane sapphire substrate by two-dimensional (2D) growthmode. For the growth of GaN, Ga flux of 3.7×10−8 torr as a beam equivalent pressure (BEP) and a plasma power of 150W with a nitrogen flow rate of 0.76 sccm were fixed. The growth of 2D GaN growth was confirmed by in-situ reflection high-energy electron diffraction (RHEED) by observing a streaky RHEED pattern with a strong specular spot. InN films showedlower growth rates even with the same growth conditions (same growth temperature, same plasma condition, and same BEPvalue of III element) than those of GaN films. It was observed that the growth rate of GaN is 1.7 times higher than that ofInN, which is probably caused by the higher vapor pressure of In. For the growth of InxGa1-xN films with different Incompositions, total III-element flux (Ga plus In BEPs) was set to 3.7×10−8 torr, which was the BEP value for the 2D growthof GaN. The In compositions of the InxGa1-xN films were determined to be 28, 41, 45, and 53% based on the peak positionof (0002) reflection in x-ray θ-2θ measurements. The growth of InxGa1-xN films did not show a streaky RHEED pattern butshowed spotty patterns with weak streaky lines. This means that the net sticking coefficients of In and Ga, considered basedon the growth rates of GaN and InN, are not the only factor governing the growth mode; another factor such as migrationvelocity should be considered. The sample with an In composition of 41% showed the lowest full width at half maximum valueof 0.20 degree from the x-ray (0002) omega rocking curve measurements and the lowest root mean square roughness valueof 0.71nm.

In this study, we demonstrated a simple and eco-friendly method, including mechanical polishing and attrition milling processes, to recycle sputtered indium tin oxide targets to indium tin oxide nanopowders and targets for sputtered transparent conductive films. The utilized indium tin oxide target was first pulverized to a powder of sub- to a few- micrometer size by polishing using a diamond particle coated polishing wheel. The calcination of the crushed indium tin oxide powder was carried out at 1000˚C for 1 h, based on the thermal behavior of the indium tin oxide powder; then, the powders were downsized to nanometer size by attrition milling. The average particle size of the indium tin oxide nanopowder was decreased by increasing attrition milling time and was approximately 30 nm after attrition milling for 15 h. The morphology, chemical composition, and microstructure of the recycled indium tin oxide nanopowder were investigated by FE-SEM, EDX, and TEM. A fully dense indium tin oxide sintered specimen with 97.4% of relative density was fabricated using the recycled indium tin oxide nanopowders under atmospheric pressure at 1500˚C for 4 h. The microstructure, phase, and purity of the indium tin oxide target were examined by FE-SEM, XRD, and ICP-MS.

In this research, the indium dissolution properties of the waste LCD panel powders were investigated as a function of milling time fabricated by high-energy ball milling (HEBM) process. The particle morphology of waste LCD panel powders changed from sharp and irregular shape of initial cullet to spherical shape with an increase in milling time. The particle size quickly decreased to 15 until the first minute, then decreased gradually about 6 with presence of agglomerated particles after 5 minutes, which increased gradually reaching a uniform size of 13 consist of agglomerated particles after 30 minutes. The glass recovery, after dissolution, was over 99% at initial cullet, which decreased to 90.1 and 78.6% with increasing milling time of 1 and 30 minute respectively, due to a loss in remaining powder of the surface ball and jar, as well as the filter paper. The dissolution amount of indium out of the initial cullet was 208 ppm before milling, turning into 223 ppm for the mechanically milled powder after 1 minute, and nearly 146~125 ppm with further increase in milling time because of the reaction surface decrease of powders due to agglomeration. With this process, maximum dissolving indium amount (223 ppm) could be achieved at a particle size of 15 with 1 minute of milling.

In this study, nano-sized indium oxide powder with the average particle size below 100 nm is fab-ricated from the indium chloride solution by the spray pyrolysis process. The effects of the reaction temperature, the concentration of raw material solution and the inlet speed of solution on the properties of powder were studied. As the reaction temperature increased from 850 to , the average particle size of produced powder increased from 30 to 100 nm, and microstructure became more solid, the particle size distribution was more irregular, the intensity of a XRD peak increased and specific surface area decreased. As the indium concentration of the raw material solution increased from 40 to 350 g/l, the average particle size of the powder gradually increased from 20 to 60 nm, yet the particle size distribution appeared more irregular, the intensity of a XRD peak increased and spe-cific surface area decreased. As the inlet speed of solution increased from 2 to 5 cc/min., the average particle size of the powder decreased and the particle size distribution became more homogeneous. In case of the inlet speed of 10 cc/min, the average particle size was larger and the particle size distribution was much irregular compared with the inlet speed of 5 cc/min. As the inlet speed of solution was 50 cc/min, the average particle size was smaller and microstructure of the powder was less solid compared with the inlet speed of 10 cc/min. The intensity of a XRD peak and the variation of specific area of the powder had the same tendency with the variation of the average par-ticle size.

액정 디스플레이는 가벼운 무게, 작은 부피, 낮은 비용, 낮은 전력 소비 등의 이유로 PC 모니터, 노트북, 태블릿 등 광범위한 분야에서 사용되며 원료 사용량이 증가하게 되었다. 우수한 광전자 특성으로 인하여 액정 디스플레이에서 투명 전도 산화물 박막으로 indium-tin-oxide(ITO)가 사용된다. ITO는 90 wt%의 In2O3와 10 wt%의 SnO2로 이루어져 있으며 전세계 인듐 소비량의 84%는 액정 디스플레이 제조시 ITO를 형성하는데 사용된다. 일반적으로 3-8년인 액정 디스플레이의 수명을 고려하면, LCD의 폐기물은 재활용을 통하여 인듐을 생산 할 수 있는 잠재적인 대체 자원이다. 액정 디스플레이 재활용을 통하여 소각 또는 매립되는 폐기물로 인한 환경오염을 방지 할 수 있으며 또한 폐기물 내 인듐과 같은 유가금속을 재활용 하여 부가가치를 창출 할 수 있어 폐 액정디스플레이 재활용은 도시 광산 분야의 중요한 연구의 분야이다. 본 연구기관에서는 수명이 다한 사용 후 LCD TV를 해체/분리하여 액정패널, 인쇄회로기판, 냉음극관, 플라스틱케이스, 금속류 등으로 분해 하는 공정을 개발하였다. 해체/분리 공정을 통해 분리된 액정패널은 기계적으로 파쇄를 하여 유리 입자사이즈를 작게 하여 이 후 금속 회수를 용이하게 하였다. 본 연구에서는 파쇄 된 액정 디스플레이 유리에서 인듐을 회수하기 위하여 산을 이용하여 용출을 하였다. 가능한 용출 변수를 실험을 통하여 최적화 하였다. 액정 디스플레이에 인듐 함유량이 매우 낮아 특별히 고안된 방법을 이용하여 침출 용액을 농축하였으며 최적의 조건에서 인듐이 완전히 용출되는 것을 확인 할 수 있었다. 또한, 인듐 외 다른 금속에 대한 용출을 최소화 하였다.

본 연구는 천연 인듐의 중성자폭획 후에 발생된 감마선을 12개의 BGO(Bi4Ge3O12)섬광검출기로 구성된 검출장치를 이용하여 즉발감마선을 측정하여 중성자공명에의해서 발생된 감마선을 분석하여 중성자의 에너지 1 ~ 300 eV영역에 대하여 공명에너지를 분석하였다. 사용되어진 검출장치는 시료에서 발생된 즉발감마선에 대하여 모든 감마선을 측정할 수 있는 기하학적인 구조로 만들어졌다. 중성자원으로는 교토대학의 원자로연구소의 46-MeV 전자선형가속기의 광핵반응에서 발생하는 중성자를 이용하였다. 중성자발생원으로부터 검출기까지의 거리가 12.7 ± 0.02m 이므로 광핵반응에서 발생하는 강한 X선의 영향을 고려하여 수 keV영역이하의 중성자에너지에 대하여 중성자공명을 측정하였다. 측정되어진 공명들은 1 eV이상의 에너지 영역에서 거대 공명들을 측정하였고 이들 공명들은 이론 에서 알려진 값들과 비교하였다. 본 연구를 통하여 기존에 알려진 거대 공명의 에너지를 확인하였고, 100 eV이상의에너지 영역에서의 공명에너지들에 대한 평가에 의한 이론값들이 실제로 존재하는 공명임을 실험적으로 확인하였다. 1 keV이상의 영역에 대하여는 공명이 연속적인 구조를 보이고 있음을 실험적으로 확인했으며 공명에 대하여 통계적인 평가가 있어야함을 알았다. 91.49 eV 공명은 본 연구를 통하여 처음 발견되어진 공명이라 볼 수 있다.