• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.6
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• pp.1115-1121
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• 2007

[ $Bi_2Sr_2Ca{_{n-1}}Cu_nO_x$ ](n=0,1,2) thin fans have been fabricated by co-deposition at an ultra-low growth rate using ion beam sputtering(IBS) method. Bi 2212 phase appeared in the temperature range of 750 and $795^{\circ}C$ and single phase of Bi 2201 existed in the lower region than $785^{\circ}C$. Whereas, $PO_3$ dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with $T_c$(onset) of about 90 K and $T_c$(zero) of about 45 K is obtained. Only a small amount of CuO in some films was observed as impurity, and no impurity phase such as $CaCuO_2$ was observed in all of the obtained films.

• Electrical & Electronic Materials
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• v.10 no.5
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• pp.447-452
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• 1997

Effects of metal impurities in insulation of distribution cables on electrical conduction of distribution cables was investigated. Samples of Al, Cu, Fe are fabricated as metallic impurities, and measured electrical conductivity in the voltage range of 0~10 KV. Temperature dependent effect of hysteresis curves and the relationship between forward and reverse current due to impurity content are discussed.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.167-167
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• 2009

결정질실리콘 태양전지를 제조함에 있어 실리콘 기판 내의 금속 불순물들은 소자제작 시에 성능 저하의 원인으로 작용한다. 따라서 본 연구에서는 실리콘 기판에 Cr, Cu, Ni 불순물을 강제 오염시킨 후 태양전지를 제작하여 각각의 불순물에 대한 특성을 조사 하였다. p-type 실리콘 기판을 오염시키기 위해 일정 시간동안 표준용액에 담근 후 질소 분위기에서 열처리 하여 불순물을 확산시켰다. 이후 상용 공정을 이용하여 태양전지를 제작하고 기판내 금속불순물 농도에 따른 태양전지의 동작특성을 분석하였다.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.929-931
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• 1999

BSCCO thin films have been fabricated by co-deposition at an ultralow growth rate using ion beam sputtering(IBS) method. Bi 2212 phase appeared in the temperature range of 750 and $795^{\circ}C$ and single phase of Bi 2201 existed in the lower region than $785^{\circ}C$. Whereas, ozone gas pressure dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with $T_c$(onset) of about 90 K and $T_c$(zero) of about 45 K is obtained. Only a small amount of CuO in some films was observed as impurity, and no impurity phase such as $CaCuO_2$ was observed in all of the obtained films.

• 한국초전도학회:학술대회논문집
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• 2008.08a
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• pp.45-45
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• 2008

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.222-225
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• 2000

BSCCO thin films have been fabricated by co-deposition at an ultralow growth rate using ion beam sputtering(IBS) method. Bi 2212 phase appeared in the temperature range of 750 and $795^{\circ}C$ and single phase of Bi 2201 existed in the lower region than $785^{\circ}C$. Whereas, $Po_3$ dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with $T_c$ (onset) of about 90 K and $T_c$(zero) of about 45 K is obtained. Only a smd amount of CuO in some films was observed as impurity, and no impurity phase such as $CaCuO_2$ was observed in d of the obtained films.

• Journal of Powder Materials
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• v.4 no.2
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• pp.122-132
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• 1997

Nanostructured(NS) W-Cu composite powders of about 20~30 nm grain size were synthesized by mechanical alloying. The properties of NS W-Cu powder and its sintering behavior were investigated. It was shown from X-ray diffraction and TEM analysis that the supersaturated solid solution of Cu in W was not formed by the mechanical alloying of mixed elemental powders, but the mixture of W and Cu particles with nanosize grains, i.e., the nanocomposite powder was attained. Nanocomposite W-20wt%Cu and W-30wt%Cu powders milled for 100 h were sintered to the relative density more than 96% and 98%, respectively, by sintering at 110$0^{\circ}C$ for 1 h in $H_2$. Such a high sinterability was attributed to the high homogeneous mixing and ultra-fine structure of W and Cu phases as well as activated sintering effect by impurity metal introduced during milling.

• Journal of Powder Materials
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• v.5 no.3
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• pp.210-219
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• 1998

The W-Cu composite powders were synthesized from W and Cu elemental powders by ball-milling process, and their microstructural changes and sintering behaviors were evaluated. The ball milling process was carried out in a 3-dimensional mixer (Turbula mixer) using zirconic ($ZrO_2$) ball and alumina ($Al_2O_3$) vial up to 300 hrs. The ball-milled W-Cu powders revealed nearly spherical shape. Microstructure of the composite powders showed onion-like structure which consists of W and Cu shells due to the moving characteristic of Turbula mixer. The W and Cu elements in the composite powders milled for 300 hrs were homogeneously distributed, and W grain size in the ball-milled powder was smaller than 0.5 $\mu\textrm{m}$. Fe impurity introduced during ball milling process was very low as of 0.001 wt%. The relative sintered density of ball-milled W-Cu specimens reached about 94% after sintering at $1100^{\circ}C$.

• Journal of Ceramic Processing Research
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• v.20 no.1
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• pp.30-34
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• 2019

Copper (Cu)-incorporated silica aerogel was synthesized by a sol-gel process with two-step drying process for color modification. The microstructure of the silica aerogel was not affected significantly by the Cu concentration and an amorphous structure was maintained without any crystalline impurity phases. The textural properties of the silica aerogels investigated by using N2 adsorption-desorption isotherms exhibited the typical features of mesoporous materials. The pore size and porosity were not changed significantly even with the incorporation of Cu up to 1.5 M, which indicates negligible variation of thermal insulating properties. However, the color of the aerogel changed from white and light greenish to dark greenish with increasing Cu content. The color change of the silica aerogel was due to the modification of the electron energy band structure of silica by the Cu atomic levels. Therefore, the color of the silica aerogel powders could be manipulated by incorporating Cu without degrading the thermal insulating properties.

• Journal of the Korean Vacuum Society
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• v.13 no.2
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• pp.79-85
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• 2004

Secondary ion mass spectrometry(SIMS) and glow discharge mass spectrometry(GDMS) were used to determine the impurity concentrations of hydrogen, carbon, and oxygen elements in the Cu and Ta films, and the results of SIMS and GDMS analysis were carefully considered. The Cu and Ta films were deposited on Si (100) substrates at zero substrate bias voltage and a substrate bias voltage of -50 V(Cu films) or -125 V(Ta films) using a non-mass separated ion beam deposition method. As a result of SIMS with Cs+ ion beam, in the case of the Cu and Ta films deposited without the substrate bias voltage, many strong peaks were observed, which is considered to be detected as a the cluster state such as CxHx, OxHx, CxOxHx. All the peaks of SIMS results could be interpreted by the combination of these dominant impurities. Moreover, it was confirmed that the quantitative results of GDMS analysis were accordant to the SIMS results.