• Journal of Magnetics
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• v.19 no.1
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• pp.68-71
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• 2014

Copper doped Zinc Oxide nanofilms were prepared using a simple and low cost wet chemical method. The microstructures, phase structure, Raman shift and optical absorption spectrum as well as magnetization were investigated for the nanofilms. Room temperature ferromagnetism has been observed for the nanofilms. Structural analyses indicated that the films possess wurtzite structure and there are no segregated clusters of impurity phase appreciating. The results show that the ferromagnetism in Copper doped Zinc Oxide nanofilms is driven either by a carrier or defect-mediated mechanism. The present work provides an evidence for the origin of ferromagnetism on Copper doped Zinc Oxide nanofilms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2267-2271
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• 2011

This study was focused on getting p-type copper-oxide thin-film semiconductors suitable for p-channel thin-film transistors. Vacuum thermal evaporation and thermal annealing were used to get copper-oxide thin-film semiconductor having properties adoptable as an active layer of thin-film transistors. n-type thin films having electron carrier density of about $10^{22}\;cm^{-3}$ before thermal annealing was converted to p-type thin films having hole carrier density of about $10^{16}\;cm^{-3}$ as the thermal annealing conditions were optimized.

• Journal of the Korean Chemical Society
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• v.23 no.3
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• pp.152-160
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• 1979

The promoting effect of Ba or Sr addition was investigated for furfural hydrogenation reaction over copper-chromium oxide catalysts. X-ray diffraction patterns showed the appearance of $BaCrO_4$ and $SrCrO_4$ phases in Ba, and Sr promoted copper-chromium oxide catalysts. For both Ba and Sr promoted catalysts, the activity decline with reaction time was much smaller compared to that of unpromoted catalyst and copper-chromium oxide catalyst dispersed on silica, reproducible EPR signals of Cr(V) were observed when CO was adsorbed. The promoting effect of Ba addition can be interpreted in terms of active sites dispersion and stabilization.

• Korean Journal of Materials Research
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• v.25 no.4
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• pp.171-176
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• 2015

We present the detection characteristics of nitrogen monoxide(NO) gas using p-type copper oxide(CuO) thin film gas sensors. The CuO thin films were fabricated on glass substrates by a sol-gel spin coating method using copper acetate hydrate and diethanolamine as precursors. Structural characterizations revealed that we prepared the pure CuO thin films having a monoclinic crystalline structure without any obvious formation of secondary phase. It was found from the NO gas sensing measurements that the p-type CuO thin film gas sensors exhibited a maximum sensitivity to NO gas in dry air at an operating temperature as low as $100^{\circ}C$. Additionally, these CuO thin film gas sensors were found to show reversible and reliable electrical response to NO gas in a range of operating temperatures from $60^{\circ}C$ to $200^{\circ}C$. It is supposed from these results that the p-type oxide semiconductor CuO thin film could have significant potential for use in future gas sensors and other oxide electronics applications using oxide p-n heterojunction structures.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.49.2-49.2
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• 2010

Copper oxide films have been deposited on silicon substrates by direct current magnetron sputtering of Cu in O2 / Ar gas mixtures. The target oxidation occurring as a result of either adsorption or ion-plating of reactive gases to the target has a direct effect on the discharge current and the resulting composition of the deposited films. The kinetic model which relates the target oxidation to the discharge current was proposed, showing the one-to-one relationship between discharge current characteristics and film stoichiometry of the deposited films.

• Journal of the Korean Ceramic Society
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• v.54 no.1
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• pp.61-65
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• 2017

Examined in this study were the effects of copper oxide (II) addition and sintering conditions on the chromatic characteristics of copper glaze. Oxidatively sintered samples exhibited the negative increase of $CIEa^*$ and the positive increase of $CIEb^*$ with the increase of CuO concentration, leading to Green and Green-Yellow coloration. On the other hand, $CIEa^*$ and $CIEb^*$ of reductively sintered samples were positively increased in direct proportion. The green color of oxidatively sintered samples was originated from the $Cu^{2+}$ ions formed by the dissolution of CuO. The reductively sintered samples resulted in dull tone red color with low chroma. Such behavior seems to be influenced by the interplay of metal Cu aggregation, metal Cu globule, and $Cu_2O$ formed in the glaze layer through the redox interaction of CuO during the sintering process.

• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.176-182
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• 2014

Using alkali treatment solution, neutrality treatment solution and acid treatment solution, the surface corrosion layer of copper plates and bronze plates that have been artificially corroded using HCl, $H_2SO_4$ and $HNO_3$ solutions were removed. In the case of alkali treatment solution, only air oxidation in the form of black tenorite and white cuproous chloride remained without being removed. In the case of using a neutrality treatment solution, a anhydrous type layer of reddish brown cupric chloride remained without being removed, together with this black and white corrosion substance. In the case of using an acid treatment solution, this red corrosion substance also remained, but all of the oxide was removed on the surface of the specimen that was treated by alternatively using alkali treatment solution and acid treatment solution. In the case of this treatment solution with the order of alkali-acid, oxidation no longer proceeded only through the distilled water cleaning process after treatment, thereby showing that oxidation from the cleaning solution no longer proceeded.

• Journal of Powder Materials
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• v.30 no.4
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• pp.332-338
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• 2023

Thermite welding is an exceptional process that does not require additional energy supplies, resulting in welded joints that exhibit mechanical properties and conductivity equivalent to those of the parent materials. The global adoption of thermite welding is growing across various industries. However, in Korea, limited research is being conducted on the core technology of thermite welding. Currently, domestic production of thermite powder in Korea involves recycling copper oxide (CuO). Unfortunately, controlling the particle size of waste CuO poses challenges, leading to the unwanted formation of pores and cracks during thermite welding. In this study, we investigate the influence of powder particle size on thermite welding in the production of Cu-thermite powder using waste CuO. We conduct the ball milling process for 0.5-24 h using recycled CuO. The evolution of the powder shape and size is analyzed using particle size analysis and scanning electron microscopy (SEM). Furthermore, we examine the thermal reaction characteristics through differential scanning calorimetry. Additionally, the microstructures of the welded samples are observed using optical microscopy and SEM to evaluate the impact of powder particle size on weldability. Lastly, hardness measurements are performed to assess the strengths of the welded materials.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.453-453
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• 2013

유기 태양전지는 저비용으로 제작이 가능하고 제작이 용이한 장점을 가지고 있으므로 많은 그룹에서 관심을 가지고 있다. 정공 수송층으로 사용되는 PEDOT:PSS는 많이 사용되지만 강한 산성 특성 때문에 ITO 전극에 식각이 되므로 문제가 있다. 그러므로 산화물 반도체 $WO_3$, $MoO_3$, 그리고 $V_2O_3$ 등이 태양전지에 많이 만들어지고 있다. 특히 copper oxide는 높은 광흡수율을 가지고 있으므로 태양전지에 사용하는 데 많은 기대되는 물질이다. Copper oxide 박막은 열증착 법, 스프레이 필로시스, 전기화학 증착, 화학증착법, 그리고 솔-젤법 등 다양한 증착 방법이 있다. 넓은 면적의 소자를 제작할 경우 솔-젤 방법은 기존의 증착법에 비해 낮은 비용으로 제작, 높은 성장율, 그리고 높은 기계적 탄력성의 장점이 있다. 솔-젤법으로 만든 copper oxide는 P3HT의 HOMO (high occupied molecular orbital)와 비슷한 위치에 접하고 있으므로 정공수송층으로 적합하다. 본 연구에서 제작된 태양전지의 구조는 ITO/P3HT:PCBM/CuxO로 구성되어 있다. ITO가 $10{\Omega}$/sq의비저항을 가지고 있었고 UV 처리를 하였다. 그 위에 P3HT:PCBM (1:0.8 weight)를 스핀 코팅하였다. 마지막으로 0.1 M $Cu_xO$용액은 Cu (II) acetate monohydrate를 소스로 2-methoxyethanol ($C_3H_8O_2$)의 용제와 안정제로 monoethanolamine ($C_2H_7NO$)을 섞어서 만들었다. 그리고 P3HT:PCBM 위에 스핀 코팅하였고 열증착 방법으로 전극인 Ag 을 증착하여 최종 소자를 만들었다. Cu(II) acetate의 소스로 제작된 박막의 투과율 측정을 통해 에너지 밴드갭을 구할 수 있었다. Copper oxide 박막은 다결정구조 이므로 다중 밴드갭으로 구성되어지는 것을 알 수 있었다. 최종적으로 만들어진 소자를 열처리를 통해 소자 특성을 조사했더니 250도에서 가장 좋은 결과를 얻을 수 있었다.

• Journal of the Korean Ceramic Society
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• v.37 no.8
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• pp.799-804
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• 2000

Coulometric titration experiments have been done for copper doped cobaltous oxide (Co1-xCux)1-$\delta$ O with various dopant concentrations. We present the obtained experimental data and compare our results to those of previous thermogravimetric investigation. The experimental data are fitted by theoretical calculations based on various defect models. For this modeling, we considered different types fo major defects like copper in substitutional and interstitial lattice sites as well as copper vacancy. We also introduced the copper evaporation effect during titration experiment into our consideration.