• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.10a
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• pp.58-58
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• 2003

Silver doped ZnO (SZO) films were prepared by rf magnetron sputtering on glass substrates with extraordinary designed ZnO target. With the doping source for target, use AgNO$_3$ powder on a various rate (0, 2, and 4 wt.%). We investigated dependence of coating parameter such as dopant content in target and substrate temperature in the SZO films. The SZO films have a preferred orientation in the (002) direction. As amounts of the Ag dopant in the target were increased, the crystallinity and the transmittance and optical band gap were decreased. And the substrate temperature were increased, the crystallinity and the transmittance were increased. But the crystallinity and the transmittance of SZO films were retrograde at 200$^{\circ}C$. Upside facts were related with composition. In addition, the Oxygen K-edge features of the SZO films were investigated by using near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Changes of optical band gap of the SZO films were explained compared with XRD, XPS and NEXAFS spectra.

• Journal of the Korean Ceramic Society
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• v.40 no.5
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• pp.447-454
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• 2003

Samples were prepared by the solid-state reaction method. The nominal composition of the samples was B $i_{1.84}$P $b_{0.34}$S $r_{1.91}$C $a_{2.03}$C $u_{3.06}$ $O_{10+{delta}$ prepared from powder of B $i_2$ $O_3$, PbO, SrC $O_3$, CaC $O_3$, and CuO. They were pulverized, mixed with AgO, A $u_2$ $O_3$and MgO of 50 wt%. Finally, they were sintered at 820 to 85$0^{\circ}C$ in air. The structural characteristics, the microstructure of surface and the critical temperature with respect to the each samples were analyzed by XRD, $T_{c}$, SEM and EDS respectively. It was found that the the critical temperature of the silver oxide additive samples (99.58 K) is higher than those of gold or magnesium oxides additive samples, but all those values are lower than that of pure Bi-2223 phase. The microstructure of surface showed the tendency which the AgO additive samples become more minuteness than A $u_2$ $O_3$ and MgO additive samples.s.samples.s.

• Korean Journal of Materials Research
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• v.4 no.4
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• pp.406-415
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• 1994

The effects of fabrication method and condition on critical current density of Ag sheathed Bi- 2223 superconducting tapes by powder-in-tube method were studied. The highest critical current density (Jc) in the whole process was measured in the repeative heat treatment of 250 hour and mechanical deformation of 2 times. These results are suggested that the high-Tc phase at the heat treatment of 250 hour was superior and the good grain alignment at the mechanical deformation of 2 times was analyzed by XRD pattern. The highest critical current density obtained by pressing method was $1.05\times 10^4A/\textrm{cm}^2$ and $0.78\times 10^4A/\textrm{cm}^2$ in case of rolling method. The multifilamentary wires with 7 and 49 filaments were fabricated to check the applicability of pressing and rolling method for preparing multifilaments wire. The critical current density of 7 filaments tapes prepared by pressing showed $0.45 \times 10^{4}A/\textrm{cm}^2$ and $0.20 \times 10^{4}A/\textrm{cm}^2$ for 49 filaments tapes prepared by rolling.

• Proceedings of the KWS Conference
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• 2007.11a
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• pp.245-247
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• 2007

Sn-base solder bump is mainly used in micro-joining for flip chip package. The quantity of intermetallic compounds that was formed between Cu pad and solder interface importantly affects reliability. In this research, micro-bump was fabricated by two binary electroplating and the intermetallic compounds(IMCs) was estimated quantitatively. When the micro Sn-Ag solder bump was made by electroplating, SiC powder was added in the plating solution for protecting of intermetallic growth. Then, the intermetallic compounds growth was decrease with increase of amount of SiC power. However, if the mount of SiC particle exceeds 4 g/L, the effect of the growth restraint decrease rapidly.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.745-746
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• 2006

This lecture introduces new press, adapter and control concepts to size multi-level sintered components. The essential thing here is that the advantages of the multi-plate technology have been applied to the sizing adapter concept. Thus, the new concept meets the demands for a modern P/M manufacture and offers sufficient potential to size any future, complex sintered components such as synchronizer hubs, oil pump wheels and VCT parts with highest precision. Furthermore, it outlines a new flexible concept for the parts transfer, including feeding, orientation and lubrication while responding to the high demands on process stability and short change-over times.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1307-1308
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• 2006

The purpose of this study was to examine the interfacial reaction between diamond grits and Ni-based, Ag-based, brazing filler metal, respectively. The morphology of the interface between diamond grits and Ni-based, filler metal exhibited a very good condition after this heat treatment. Cr-carbide and Ni-rich compounds were detected by XRD analysis in the vicinity of the interface between diamond grits and Ni-based, filler metal after vacuum induction brazing. Chromium carbide is considered to play an important role in the high bonding strength achieved between diamonds grits and the brazing alloy.

• Journal of Powder Materials
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• v.15 no.6
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• pp.466-470
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• 2008

Experiments with a URT-0.5 accelerator (0.5 MeV, 50 ns, 1 kW) generating a nanosecond electron beam for irradiation of silver nitrate in various liquid solutions (water and toluene) were performed with the aim of producing silver nanopowders. A radiochemical reaction allows making weakly agglomerated pure Ag powders with particles of 10-15 nm and 30-50 nm in size by irradiation in toluene and water respectively. The injection of the nanosecond electron beam energy to the solution is optimal. As the absorbed dose increases, the output of the radiochemical reaction does not grow, but more agglomerated powders are synthesized.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.463-464
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• 2006

광산업 및 디스플레이 산업의 발전에 따라 관련 제품의 핵심 부품 및 소재 개발이 매우 중요하게 대두되고 있다. 전계방출 소자 및 back light가 되는 나노 발광체의 핵심소재중 하나인 CNT paste는 국내외에서 연구가 진행중이다. 본 연구에서는 메탄올속에서 초음파를 이용하여 분산시킨 CNT 분말, 유기 바인더, 용매, glass frit, Ag powder 등을 사용하여 paste를 만들고, TGA(Thermogravimetric Analyzer)와 SEM(Scanning Electron Microscopy) 분석에 의해 제조 공정의 최적화를 실시하였다.

• Journal of the Korean Chemical Society
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• v.61 no.4
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• pp.191-196
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• 2017

One-phase method to prevent the initial formation of Ag(I) thiolate layered materal from the mixture of $AgNO_3$ and thiols was previously developed to generate TP (Thiolate-Protected)-nanosilver. In this modified method, $AgNO_3$ is added to the mixtures of $NaBH_4$ and thiols in ethanol. This method was so successful that it was applied to synthesize TP-nanogold and nanoplatinum. The synthesis and characterization of these nanoparticles by ultraviolet-visible (UV-vis) absorption spectra, transmission electron microscopy (TEM) pictures, X-ray powder differaction (XRD) patterns and infrared(IR) spectra are described. The results show that colloidal nanoparticles are spherical or oval shape and the mean sizes for TP-nanogold and nanoplatinum are about 3~7 nm and below 2 nm, respectively. The conformation of polymethylene [$-(CH_2)_7-$] sequence in octanethiolate attached to nanogold was elucidated as trans.

• Journal of Digital Convergence
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• v.18 no.4
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• pp.309-314
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• 2020

Polymethyl methacrylate (PMMA) is concerned with promoting oral infection due to its low antibacterial activity. To overcome this, the nanoparticles of Ag-MSN, nGO, and CNP were mixed with MMA liquid in a weight ratio of 0, 0.25, 0.5, 1.0, 2.0% compared to resin powder using Orthocryl from Dentarum, a calibration resin, and then instructed by the manufacturer. Accordingly, a specimen for calibration was prepared by mixing PMMA: MMA (1.2: 1) ratio, and physical properties of the calibration resin, antifungal experiments, and statistical analysis were performed. As a result of antibacterial experiments, the antibacterial properties of Ag-MSN increased. In nGO, the antibacterial adhesive effect increased hydrophilicity, not a change in surface roughness. The higher the CNP concentration, the higher the antibacterial activity. This suggests its potential usefulness as an antibacterial dental material for orthodontic devices and temporary restorations.