• Korean Journal of Materials Research
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• v.11 no.9
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• pp.802-809
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• 2001

Electroplating is an attractive alternative deposition method for copper with the need for a conformal and conductive seed layer In addition, the Cu seed layer should be highly pure so as not to compromise the effective resistivity of the filled copper interconnect structure. This seed layer requires low electrical resistivity, low levels of impurities, smooth interface, good adhesion to the barrier metal and low thickness concurrent with coherence for ensuring void-free fill. The electrical conductivity of the surface plays an important role in formation of initial Cu nuclei, Cu nucleation is much easier on the substrate with higher electrical conductivities. It is also known that the nucleation processes of Cu are very sensitive to surface condition. In this study, copper seed layers deposited by magnetron sputtering onto a tantalum nitride barrier layer were used for electroplating copper in the forward pulsed mode. Prior to electroplating a copper film, the Cu seed layer was cleaned by plasma H$_2$ and $N_2$. In the plasma treatment exposure tome was varied from 1 to 20 min and plasma power from 20 to 140W. Effects of plasma pretreatment to Cu seed/Tantalum nitride (TaN)/borophosphosilicate glass (BPSG) samples on electroplating of copper (Cu) films were investigated.

• Journal of Animal Science and Technology
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• v.63 no.6
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• pp.1386-1396
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• 2021

Copper is an essential mineral for pigs, thus it is used as a feed additive in the forms of copper sulfate. Therefore, this study aimed at characterizing the fecal microbiota shifts in pigs as fed by different forms of copper supplementation. 40 growing pigs aged 73 ± 1 days with an average weight of 30.22 ± 1.92kg were randomly divided into 5 groups. The control group (CON) fed with basal diet, while treatment groups were fed a basal diet supplemented with 100 ppm/kg of copper sulfate (CuSO₄), Cu-glycine complex (CuGly), Cu-amino acid complex (CuAA), and Cu-hydroxy(4methylthio)butanoate chelate complex (CuHMB) for 28 days of trial, respectively. The data presented the comparison between inorganic and organic copper supplementation through gut microbiota in growing pigs. Alpha and Beta diversity anaylsis resulted in copper supplementation did shifted gut microbioal community structure. At the phylum level, Firmicutes and Bacteroidetes were the most abundant phyla at all times regardless of treatment. At the genus level, the relative abundances of Prevotella, Lactobacillus, Megasphaera, and SMB53 of the CuGly and CuHMB groups were significantly higher than those of copper sulfate and basal diet groups. Overall, this study may provide the potential role of organic copper replacing inorganic copper, resulting in increased beneficial bacteria in the pig gut.

• Journal of the Korean Ceramic Society
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• v.50 no.6
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• pp.518-522
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• 2013

This study investigatesthe coloration mechanism by identifying the factor that affects thered coloration of copper red glazesin traditional Korean ceramics. The characteristics of the reduction-fired copper red glaze's sections are analyzed using an optical microscope, Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). The sections observed using an optical microscope are divided into domains of surface, red-bubble, and red band. According to the Raman micro spectroscopy analysis results, the major characteristic peak is identified as silicate in all three domains, and the intensity of $Cu_2O$ increases toward the red band. In addition, it is confirmed that the most abundant CuO exists in the glaze bubbles. Moreover, CuO and $Cu_2O$ exist as fine particles in a dispersed state in the surface domain. Thus, Cu combined with oxygen is distributed evenly throughout the copper red glaze, and $Cu_2O$ is more concentrated toward the interface between body and glaze. It is also confirmed that CuO is concentrated around the bubbles. Therefore, it is concluded that the red coloration of the copper red glaze is revealed not only through metallic Cu but also through $Cu_2O$ and CuO.

• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2116-2126
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• 2016

Bacterial biofilms are spatially structured communities that contain bacterial cells with a wide range of physiological states. The spatial distribution and speciation of copper in unsaturated Pseudomonas putida CZ1 biofilms that accumulated 147.0 mg copper per g dry weight were determined by transmission electron microscopy coupled with energy dispersive X-ray analysis, and micro-X-ray fluorescence microscopy coupled with micro-X-ray absorption near edge structure (micro-XANES) analysis. It was found that copper was mainly precipitated in a $75{\mu}m$ thick layer as copper phosphate in the middle of the biofilm, while there were two living cell layers in the air-biofilm and biofilm-medium interfaces, respectively, distinguished from the copper precipitation layer by two interfaces. The X-ray absorption fine structure analysis of biofilm revealed that species resembling $Cu_3(PO_4)_2$ predominated in biofilm, followed by Cu-Citrate- and Cu-Glutathione-like species. Further analysis by micro-XANES revealed that 94.4% of copper were $Cu_3(PO_4)_2$-like species in the layer next to the air interface, whereas the copper species of the layer next to the medium interface were composed by 75.4% $Cu_3(PO_4)_2$, 10.9% Cu-Citrate-like species, and 11.2% Cu-Glutathione-like species. Thereby, it was suggested that copper was initially acquired by cells in the biofilm-air interface as a citrate complex, and then transported out and bound by out membranes of cells, released from the copper-bound membranes, and finally precipitated with phosphate in the extracellular matrix of the biofilm. These results revealed a clear spatial pattern of copper precipitation in unsaturated biofilm, which was responsible for the high copper tolerance and accumulation of the biofilm.

• Korean Journal of Materials Research
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• v.23 no.7
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• pp.399-403
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• 2013

The purpose of this study is to investigate the coloration characteristics by identifying the factor affecting red coloration of copper red glaze in traditional Korean ceramics. This study analyzed the characteristics of the reduction-fired copper red glaze by using XRD, Raman spectroscopy, EDX and UV-vis spectroscopy. As a result of XRD analysis, the glaze completely melted and amorphous glass appeared overall, and the characteristic peak of metal Cu was shown together. In addition, as a result of Raman analysis, the characteristic bands of CuO and $Cu_2O$ were shown together. The distribution of component elements was observed by EDX. As a result, copper(Cu) were distributed throughout the glaze. Thus, it was shown that copper red glaze appeared the best red coloration because metal Cu, CuO and $Cu_2O$ evenly existed throughout glaze in particle colloidal state. The chroma value of the copper red glaze was CIE $L^*$ 30.07, $a^*$ 13.65, $b^*$ 3.72. Wine-Red Solution was shown by Dark Graish Red coloration.

• Journal of Animal Science and Technology
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• v.57 no.2
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• pp.6.1-6.5
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• 2015

The objectives of this study were to study the effects of different levels of dietary copper on organ indexes, tissular Cu, Zn and Fe deposition and fur quality of mink in the growing-furring periods. One hundred and five standard dark male mink were randomly assigned to seven groups with the following dietary treatments: basal diet with no supplemental Cu (Control); basal diet supplemented with either 6, 12, 24, 48, 96 and 192 mg/kg Cu from copper sulphate, respectively. The colour intensity scores displayed a linear trend (P = 0.057). The spleen Cu concentrations responded in a linear (P < 0.05) fashion with increasing level of Cu, but copper supplementation did not affect speen concentrations of Fe or Zn. Supplemental dose of Cu linearly increased (P < 0.05) liver Cu and Fe concentrations but did not alter (P > 0.10) liver Zn. Our results indicate that Cu plays an important role in the pigmentation in growing-furring mink, and supplemental dietary Cu in growing-furring mink improve hair colour, and copper has limited effects on liver mineral deposition.

• Journal of the Korean Ceramic Society
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• v.38 no.11
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• pp.1000-1007
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• 2001

In an evacuated tube solar collector, the stable sealing of the heat pipe to the glass tube is important for the collector to use for a long period of time. The sealing of copper tube to the glass is quite difficult because of the large differences in the physical and chemical properties of the two materials. In this study, therefore, a proper copper oxide layer was induced to improve the chemical bonding of the two materials, and the oxidation state of copper and the interface between copper and glass were examined by XRD, SEM and EDS. Its bonding strength was also measured. Cu$_2$O was formed when the bare copper was heat-treated under 600$^{\circ}C$, while CuO oxide layer was formed above that temperature. The bonding state of CuO to the copper was very poor. The borate treatment of the copper, however, extend the stable forming of Cu$_2$O layer to 800$^{\circ}C$. Borosilicate glass tube was sealed to a copper tube by Housekeeper method only when the sealing part was covered with Cu$_2$O layer. The bonding strength at the interface was measured 354.4N, its thermal shock resistance was acceptable.

• Journal of the Korean Electrochemical Society
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• v.10 no.1
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• pp.14-19
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• 2007

The corrosion and passivation of copper was investigated with the copper rotating disk electrode(Cu-RDE) in borate buffer solution. It has been observed with the mixed potential theory that the corrosion potential for the rotation rate increase under the convective diffusion condition was increased. It was suggested that the chemical intermediates and product 13. the copper oxidation were $Cu(OH)_{ads},\;{Cu(OH)_2}^-,\;Cu_2O,\;Cu(OH)_2,\;and\;CuO$.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.22 no.1
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• pp.55-66
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• 2024

In this study, we investigated the suppression of the corrosion of cast iron in a copper-cast iron double-layered canister under local corrosion of the copper layer. The cold spray coating technique was used to insert metals with lower galvanic activity than that of copper, such as silver, nickel, and titanium, between the copper and cast iron layers. Electrochemically accelerated corrosion tests were performed on the galvanic specimens in KURT groundwater at a voltage of 1.0 V for a week. The results revealed that copper corrosion was evident in all galvanic specimens of Cu-Ag, Cu-Ni, and Cu-Ti. By contrast, the copper was barely corroded in the Cu-Fe specimens. Therefore, it was concluded that if an inactive galvanic metal is applied to the areas where local corrosion is concerned, such as welding parts, the disposal canister can overcome local or non-uniform corrosion of the copper canister for long periods.

• Journal of Environmental Science International
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• v.21 no.5
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• pp.555-562
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• 2012

The experimental determination of equilibrium constants is required to estimate concentrations of reagents and/or products in environmental chemical reactions. For an example, the choice of copper (Cu) complexation reactions was motivated by their fast kinetics and the ease of measurement of Cu by an ion-sensitive electrode. Each individual titrant of sulfate ($SO{_4}^{2-}$) and oxalate ($C_2O{_4}^{2-}$) was expected to have its own unique characteristics, depending on the bonding in Culigands connected to the aqueous species. The complexation reaction of Cu with $SO{_4}^{2-}$ somewhat fast reached equilibrium status compared with $C_2O{_4}^{2-}$. The experimental equilibrium constants ($K_{eq}$) of copper sulfate ($CuSO_4$) and copper oxalate ($CuC_2O_4$) were determined $10^{2.2}$ and $10^{3{\sim}4.3}$, respectively.