• Journal of the Korean Vacuum Society
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• v.15 no.5
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• pp.485-492
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• 2006

Two new copper(I) complexes with organic ligands, $[Cu^I(hfac)]_2(DVTMSO)$ and $[Cu^I(hfac)]_2(HD)$ (hfac=hexafluoroacetylacetonate, DVTMSO=1,2-divinylte-tramethyl-disiloxane, HD=1,5-hexadiene) were synthesized and used for copper metal-organic chemical vapor deposition. In these compounds, two Cu(hfac) fragments are bonded by one neutral ligand forming unusual structure with respect to other Cu(I) complexes. The compounds exhibited relatively high volatility and stability when compared to other copper(I) precursors. By using the reported compounds as precursors, a continuous Cu layer was not formed but the Cu islands were only observed. And the shape and size of Cu islands are significantly changed as a function of the substrate temperature.

• Journal of the Korean Chemical Society
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• v.23 no.2
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• pp.80-87
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• 1979

The active site for the formation of acrolein in propylene oxidation reaction over copper(Ⅱ)-exchanged zeolite Y has been studied. At the early stage of the reaction, the formation of hydrocarbons was observed. The formation of hydrocarbons decreased gradually during the course of reaction, apparently due to the poisoning the Bronsted acid sites. The formation of acrolein was quite low when the formation of hydrocarbons was proceeding. The formation of acrolein was depend on the copper ion content and this can be related to the availability of the copper ions inside the supercage. It seems that it is the copper ion not the Bronsted acid site which is primarily responsible for the formation of acrolein.

• Conservation Science in Museum
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• v.28
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• pp.89-108
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• 2022

Among about 500,000 characters in metal types in National Museum of Korea, this study conducts a statistical analysis of 62 metal types from the early Joseon Dynasty, including 33 gabinja (甲寅字) types and 29 eulhaeja (乙亥字) Hangeul types by examining the shape, measuring the specific gravity, and identifying the components based on previously-studied Joseon metal types. Among them, 33 gabinja types and 24 eulhaeja types were made of two-component bronze (copper and tin) (Group A), and four eulhaeja types were produced with three-component bronze (copper, tin and lead). (Group B), and one eulhaeja type was created with two-component bronze (copper and tin) with a high tin content (Group C). By comparing with imjinja (壬辰字) types of the late Joseon Dynasty based on multiple statistical analyses of type components, this study confirms that late-Joseon types have low copper content and high zinc and lead content, and therefore it may be possible to distinguish between the types of early and late Joseon Dynasty.

• Journal of the Korean Chemical Society
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• v.36 no.4
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• pp.477-484
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• 1992

Using semiempirical molecular orbital method, ASED-MO of extended Huckel Theory, we were investigated chemical bonds and electronic properties of Cu atom in a chain and a layer for Y123 and Y124 superconductors from VEP (valence electron population), DOS (density of state), and COOP (crystal orbital overlap population). In order to investigate environmental effects of Cu atom for Y123 and Y124 superconductors, we introduced charged cluster models with point charge and without point charge into our calculations. As a result of ASED-MO calculations, the Cu atom in the layer acts as electron acceptor and the Cu atom in the chain acts as electron donor for Y123 and Y124 superconductors. The oxidation state of Cu atom for Y123 and Y124 superconductors without point charge is higher in the chain than in the layer. The oxidation state of Cu atom in the layer for Y123 superconductor is higher than that in the layer for Y124 superconductor. The Cu atom in the layer and the chain for Y123 superconductor does not largely affect on the environmental effect. However, the Cu atom in the layer and the chain for Y124 superconductor does largely affect on it. Also, electron population and chemical bonding of Cu1-O4, Cu2-O4, and Cu1-Cu2 for Y123 superconductor are far different from Y124 superconductor.

• Korean Journal of Optics and Photonics
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• v.3 no.1
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• pp.50-54
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• 1992

Maskless depositon of copper onto n-doped and p-doped Si in an aqueous copper sulfate solution is investigated. On p-doped Si substrates, microscopic $(~10\mu\textrm{m}$) copper spots are deposited by illuminating continuous wave $Ar^+$ laser beam of wavelength 514.5 nm. Copper deposition on n-doped Si substrates is also achieved by shinning second harmonic pulses $(pulse width~25 nsec, \lambda=530 nm)$ of a passively Q-switched Nd:YAG laser. The observed deposition is attributed to the electric field resulting from the Galvanic potential of a semiconductor-electrolyte junction.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.3
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• pp.55-60
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• 2020

The recent semiconductor packaging technology is evolving into a high-performance system-in-packaging (SIP) structure, and copper-to-copper bonding process becomes an important core technology to realize SIP. Copper-to-copper bonding process faces challenges such as copper oxidation and high temperature and high pressure process conditions. In this study, the bonding interface quality of low-temperature copper-to-copper bonding using a two-step plasma treatment was investigated through quantitative bonding strength measurements. Our two-step plasma treatment formed copper nitride layer on copper surface which enables low-temperature copper bonding. The bonding strength was evaluated by the four-point bending test method and the shear test method, and the average bonding shear strength was 30.40 MPa, showing that the copper-to-copper bonding process using a two-step plasma process had excellent bonding strength.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.48.2-48.2
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• 2009

구리 나노분말은 우수한 전기전도도와 상대적으로 저렴한 가격으로 주목을 받고 있어이를 이용한 다양한 기술들이 개발 중에 있다. 이들 중 잉크젯 프린팅용 구리 나노잉크는 기존의 포토리소그래피방식의 복잡한 공정단계와 이로 인한 단가 인상을 해결할 수 있는 공정으로 기대되는 잉크젯 프린팅에 구리를 사용할 수 있게 해주어 광범위한 응용이가능할 것으로 기대되어 많은 연구가 진행되고 있는 분야이다. 실제로 구리 나노분말의 이용하게 될 때에있어서 어려운 점 중 하나가 바로 빠른 표면 산화의 문제이다. 이를 막기 위해 본 연구에서는 건식 분말코팅 방법을 이용해 octanethiol 자기조립박막을 구리 표면에 부착한 분말을 사용하여 구리 나노분말용액을 제조하는 실험을 수행하였다. 건식 분말 코팅에 의해 산화 방지막이 부착된 분말을 표면 활성제인 Diethanolamine을 이용해 안정적으로 분산시켜 잉크로 사용이 가능한 용액을 제조해 보고, 분산된 용액의 안정도를 확인하기 위해 zetapotential analyzer를이용하여 분산도를 분석하였다. 또한 분산된 용액의 활용 실험을 위해 유리 기판에 바른 용액을 질소 분위기의튜브로에서 $250^{\circ}C$, $300^{\circ}C$, $400^{\circ}C$의 온도에서 30분간 소결을 진행한 후 probe-station을 이용하여 전기 전도도를 측정하였다. 이렇게제작된 샘플은 Scanning Electronic Microscope 를 이용하여 소결된 상태의 표면의 사진을 찍어 서로 비교해보았다. $300^{\circ}C$에서 소결한 시편부터 소결이 시작되어 $400^{\circ}C$에서 소결한 시편은 다량의 소결목이 형성되었다.

• Korean Journal of Heritage: History & Science
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• v.54 no.1
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• pp.4-17
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• 2021

This study analyzed 19 samples of harness fittings and pendants, which were excavated in Tomb No. 15 in Songhyeon-dong, Changnyeong. Harness fittings and pendants are used for ostentation, rather than practicality, and were excavated from ancient tombs in Gaya culture. So, they are considered artifacts that compare the production techniques and raw materials. This study aimed to examine the production techniques and provenience studies of Bihwa Gaya, which is estimated to be from the 5th to 6th centuries. According to the research, harness fittings were made of pure copper and were gilded with Au·Ag alloys on their surfaces. Hg was detected together and plated with a mercury amalgam method. As a result of the pendant (fish scales-pattern, oval and fish-tail shape), analysis showed that Fe in the background metal, Cu in the middle layer, and Au and Ag on the surface were the main components. The method of adhesion between Cu and Au·Ag gilded layers are plated by a mercury amalgamation method. So, it was identified by the gilt-iron·gold·bronze technique. Since the pendant (heart shaped) is found to be the main component of Fe in the background metal and Ag in the surface layer, the metal was made gilt-iron·silver technique. The background metal and gilding were additionally fixed using a rivet. The raw materials of 3 harnesses excavated from Changnyeong are plotted in zone 2 in the southern Korean Peninsula. And 16 harnesses were plotted in Chinese copper ore by Mabuchi Hishao in the Chinese Peninsula.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.151-155
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• 2006

Elastic-viscoplastic structural analysis is performed for regenerative cooling chamber of liquid rocket thrust chamber using Bodner-Partom visco-plastic model. Strain rate test was also conducted for a copper alloy at various temperatures in order to get material constants of visco-plastic model used in the structural analysis. Material constants of visco-plastic model were obtained from strain rate test results and visco-plsstic model was incorporated into finite element program, Marc, by means of user subroutine. The structural analysis results indicate that the deformation of cooling channel is mostly caused by thermal loading rather than pressure loading and confirmed structural stability of the cooling channel under operating condition.

• Journal of the Korean Chemical Society
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• v.60 no.2
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• pp.131-136
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• 2016

Copper ion induced photoluminescence (PL) quenching dynamics and recovery of the PL by zinc ions were investigated for CdSe based nanocrystals. When copper ions were added, CdSe quantum dots showed fast and dramatically PL quenching whereas PL of CdSe nanorod gradually decreased. In the presence of zinc ions, the PL of CdSe/CdS (core/shell) nanocrystals that have quenched by copper ions was efficiently recovered. It showed that the PL intensity of nanocrystals increased by 50% in a solution containing 1 μM zinc ions. The PL intensity was increasing with increasing zinc ions, and could be described by Langmuir binding isotherm model. We showcase that the CdSe based nanocrystals can be used as fluorescence turn-on sensor.