• Transactions on Electrical and Electronic Materials
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• v.16 no.5
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• pp.274-279
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• 2015

Reduced graphite oxides (rGOs) were prepared by the common graphite oxidation method and the subsequent reductions. The reduction of graphite oxides (GOs) was conducted chemically and/or thermally. To further reduce the as-prepared rGOs, GOs were treated with chemical/thermal reductions or thermal/chemical reductions, in which the reduction sequence was also considered. The structural changes of as-prepared rGOs, depending on reduction methods, were investigated by X-ray diffraction analyses, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. In addition, we discuss the structural change of the rGOs and their closely related physical and electrical properties, such as thermogravimetry, nitrogen adsorption isotherm, and sheet resistance.

• Journal of Integrative Natural Science
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• v.3 no.3
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• pp.157-161
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• 2010

New low temperature synthesis of germanium nanoparticles obtained from the reaction of germanium tetrachloride and sodium/benzophenonewere developed. These germanium nanoparticles terminated with chloride group were oxidized in air to give hydroxy-terminated germanium nanoparticles. Germanium nanoparticle containing 20(S)-camptothecin (CPT) for a noble drug delivery system were developed. FT-IR spectroscopy was used for the characterization of vibrational absorption for the germanium nanoparticle and oxidized germanium nanoparticles containing camptothecin. Electronic absorption and fluorescence properties were measured with UV-Vis and fluorescence spectrometer. The morphology of oxidized germanium nanoparticles containing camptothecin was investigated by using TEM.

• Bulletin of the Korean Chemical Society
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• v.29 no.1
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• pp.159-164
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• 2008

Two kinds of CNT/TiO2 composite photocatalysts were synthesized with multi-walled carbon nanotubes (MWCNTs) and titanium(IV) n-butoxide (TNB) by a MCPBA oxidation method. Since MWCNTs had charge transfer and semiconducting, the CNT/TiO2 composite shows a good photo-degradation activity. The XRD patterns reveal that only anatase phase can be identified for MCT composite, but the HMCT composite synthesized with HCl treatment was observed the mixed phase of anatase and rutile. The EDX spectra were shown the presence as major elements of Ti with strong peaks. From the SEM results, the sample MCT and HMCT synthesized by the thermal decomposition with TNB show a homogenous sample with only individual MWCNTs covered with TiO2 without any jam-like aggregates between CNTs and TiO2. From the photocatalytic results, we could be suggested that the excellent activity of the CNT/TiO2 composites for organic dye and UV irradiation time could be attributed to combination effects between TiO2 and MWCNTs with plausible photodegradation mechanism.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1402-1404
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• 2001

Josephson junction arrays of the type $Nb/Al-Al_2O_3/Nb$ were prepared by DC magnetron sputtering. The tunnel barrier was formed by in-situ thermal oxidation. Individual junctions were defined using selective niobium etching process(SNEP). The characteristic curves of Josephson junction arrays fabricated with and without cooling the substrate were represented. The junctions deposited without cooling showed poor characteristics(high leakage current, low gap voltage), and a high quality Josephson junction array of 2,000 junctions with high hysteresis was obtained with cooling and when operated at 74.6 GHz, it generated stable quantized voltage steps up to 2.2 V.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.8
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• pp.711-714
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• 2008

Metal-oxide-semiconductor (MOS) capacitors were fabricated to investigate the plasma damage caused by reactive ion etching (RIE) on (100) oriented silicon-on-insulator (SOI) substrates. The thickness of the top-gate oxide, SOI, and buried oxide layers were 10 nm, 50 nm, and 100 nm, respectively. The MOS/SOI capacitors with an etch-damaged SOI layer were characterized by capacitance-voltage (C-V) measurements and compared to the sacrificial oxidation treated samples and the reference samples without etching. The measured C-V curves were compared to the numerical results from corresponding 2-dimensional (2-D) structures by using a Silvaco Atlas simulator.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.286-289
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• 2004

On site, In situ soil remediation technologies are very important among the remediation technologies and in general efficiency of these technologies are turned to site characterization and environmental condition. specially using of only one technology has so many limitation factors. for example, existing state of tailing and channeling and so on. actually, filled land have high concentration cation exchange capacity because of existence in abundance soil organic matter. Therefore we used various on site in Situ technologies by phase for overcome the limitation factors. Target site is petroleum (diesel) impacted filled land and using technologies are SVE(Soil Vapor Extraction), BV(Bioventing), Bioremediation, Soil flushing, Chemical oxidation.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.365.1-365.1
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• 2014

Cobalt oxide has excellent various properties such as high catalytic activity, antiferromagnetism, and electrochromism. So cobalt oxides offer a great potential for their applications in the various areas such as optical gas sensor, catalysts for oxidation reaction, electrochromic devices, high temperature solar selective absorbers, magnetic materials, pigment for glasses and ceramics, and negative electrodes for lithium-ion batteries. We have synthesized novel cobalt complexes by simple reaction of cobalt bistrimethylsilylamide as a starting material with a lot of conventional ligands as potential cobalt oxide precursors. The studies include the facile preparation, structural characterization, and spectroscopic analysis of the new precursors. We are making efforts to grow cobalt oxide thin films using cobalt complexes newly synthesized in this study using deposition techniques.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.173.2-173.2
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• 2014

Thin nitride thin films were synthesized by reactive radio-frequency magnetron sputtering in the ultra high vacuum (UHV) chamber. To control the characteristics of thin films, tin nitride thin films were obtained various argon and nitrogen gas mixtures, especially low nitrogen gas ratios. Tin nitride thin films were analyzed with alpha step, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and 4 point probe measurement. The result of alpha step and SEM showed that the thickness of thin nitride thin films were decreased with increasing nitrogen gas ratios. The metallic tin structure was decreased and the amorphous tin nitride structure were observed by XRD with higher nitrogen gas ratios. The oxidation state of tin and nitride were studied with high resolution Sn 3d and N 1s XP spectra.

• Journal of the Korean Vacuum Society
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• v.1 no.1
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• pp.183-189
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• 1992

The characteristics of N/O(SiOz/SisN4) film on WSi2 are compared with storage node Poly-Si. Leakage current and breakdown voltage are improved and storage capacitance is decreased. The oxidation rate of WSiz is more rapid than polycrystalline silicon. Thus the thick bottom oxide on the WSiz causes to the decrease of capacitance. The out diffusion of dopant impurity in polycrystalline silicon through the silicide leads to the formation of a depletion region in the polycrystalline silicon and the decrease of depletion capacitance. That results in the decrease of the overall storage capacitance.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05b
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• pp.180-183
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• 2004

Gas separation membranes are now used in a wide variety of application areas as oxygen enrichment, hydrogen recovery, acid gas treatment, and natural gas dehydration etc [1]. Since polymeric membranes offer attractive properties for gas separation application, they have been variously studied [2-4].(omitted)