• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04a
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• pp.21-24
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• 2002

In this paper, for the study on the fabrication of YBCO superconductor wire, a double layered YBCO superconductor wire was fabricated by electrophoretic method on metal Ag wire(${\Psi}$0.8 mm). On the basis of previous researches for the fabrication of superconductor wire, the acetone suspension solution with 8 vol.% of 1% PEG(1000) was used and high molecular adhesive was experimentally performed for an improvement of the critical current density of superconductor wire. It was found that the Ag inter-layer deposited on the superconductor wire affect to the state of second YBCO film and its critical current density.

• Rapid Communication in Photoscience
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• v.4 no.1
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• pp.22-24
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• 2015

A new trinuclear complex $[Ru(TPrPc)(CO)]_2[Ru(pytpy)_2](PF_6)_2$ (TPrPc = 2,7,12,17-tetra-n-propylporphycenato dianion and pytpy = 4'-(4-pyridyl)-2,2':6',2"-terpyridine) has been synthesized and characterized as the first example of a discrete molecular wire containing metalloporohycenes as a building block. The trinuclear complex shows multiple-step redox behavior in 0.1 M n-$Bu_4NPF_6$-dichloromethane. The mononuclear $[Ru(pytpy)_2]^{2+}$ precursor shows emission at 640 nm (deaerated acetone, 298 K) upon illumination at the metal-to-ligand charge transfer (MLCT) band at 495 nm, but the trinuclear molecular wire is found to be non-emissive upon photoexcitation at the central $[Ru(pytpy)_2]^{2+}$ entity, indicating an efficient quenching ability of the axially-linked, ruthenium(II)-porphycene chromophores in an intramolecular fashion.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.53-56
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• 2003

The properties of YBCO thick film coated on Ag wire with YBCO powder is deeply affected by cracking on its surface which was deposited in organic solution by electrophoretic method. YBCO superconducting thick films were prepared on Ag wire$({\Psi}0.8mm)$ by electrophoresis in acetone with added PEG (Poly-Ethylene Glycol, 3% in Acetone), 1ml for being crack-free. The surface properties of YBCO superconducting wire was evidently improved with adding PEG. Added PEG which molecular weight is 600, 1000, 3400 was affected with variation of deposition voltages to the surface properties of samples. As a result, with adding PEG (its molecular weight is 3400), YBCO superconducting wire was better on its surface properties.

• Rapid Communication in Photoscience
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• v.3 no.3
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• pp.42-47
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• 2014

Development of molecular and supramolecular systems showing efficient photoinduced energy or electron transfer are of current research interest due to their applications in various chemical and biological processes. Various polypyridine metal complexes including Ru(II), Ru(III), Os(II), Pt(II), Fe(II), Re(I), Ir(III) and so on as a metal center introduce for expanding some more understanding of molecular-scale photoelectronics. Their complexes are concisely classified by the types of relay ligands as follows; (a) metal-direct ligand-metal system; dinuclear or trinuclear systems, (b) metal-nonconjugated ligand-metal system and metal-nonconjugated ligand system having flexible/rigid ligand, (c) metal-conjugated ligand-metal system, and (d) conjugated ligand-metal-conjugated ligand system and metal-self assembly ligand-metal system. It is pointed out that the role played by the relay ligands is important in constructing the metal complexes.

• Bulletin of the Korean Chemical Society
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• v.22 no.5
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• pp.534-536
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• 2001

• Bulletin of the Korean Chemical Society
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• v.29 no.1
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• pp.197-201
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• 2008

Conformational heterogeneity of directly linked multiporphyrin arrays with larger molecular length retards their utilities in practical applications such as two-photon absorption and molecular photonic wire. In this regard, here we adopted a way to overcome the conformational heterogeneity through hydrogen bonding by selective binding of meso aryl substituents of porphyrins (host) with urea (guest) to form helical structure. Using steady-state and time-resolved spectroscopy, we observed the enhanced fluorescence quantum yield by ~1.8 to 2.4 times, enhanced anisotropy values and the disappearance of fast fluorescence decay component in the host-guest helical forms. In addition, the enhanced nonlinear optical responses of helical arrays infer the extended inter-porphyrin electronic coupling due to a significant change in dihedral angle between the neighboring porphyrin moieties. The current host-guest strategy will provide a guideline to improve the structural homogeneity of the photonic wire.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.12
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• pp.1125-1130
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• 2003

The electrophoretic deposition method using the suspension solution with additives under the electric potential was applied for the fabrication of YBCO superconductor wire. This method was able to simplify the fabrication facilities, and produce an uniform and dense thick film. To improve the critical current density of deposited films, the additive PEGs(Poly Ethylene Glycole) with the molecular weight of 600, 1000 and 3400 were used as chemical binders for the suspension solution. The organic additive (PEG) showed better effects to the properties of YBCO superconductor wire. The PEG improved the adhesion between superconductor particles and suppressed the crack on the surface, which enhanced the surface uniformity and density of YBCO deposited film. It was found that acetone suspension solution showed better deposition properties than the others. The samples fabricated in the solution with the additive, 8 vol.% of 1% PEG(1000), showed the highest critical current density measured as 2300∼2400 A/$\textrm{cm}^2$ at 77 K, 0 T.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1182-1185
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• 2003

Recently, the research of the nano technology has been done on a lot of area over the world. Especially, the interest of them is much higher for semiconductor companies and other super accuracy processing area. In this thesis, we have approached the characteristic of the tensile and bonding of copper, frequently used to nano wires, by molecular dynamics simulation. And the simulation was done by EAM, Embedded Atom Method which has the most highest accuracy for metal. Then the feature of copper at atom space is understood through the simulation of nano wire.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.123-126
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• 2003

The electrophoretic deposition method using the suspension solution with additives under the electric potential was applied for the fabrication of YBCO superconductor wire. This method was able to simplify the fabrication facilities, and produce an uniform and dense thick film. To improve the critical current density of deposited films, the additive PEGs(Poly Ethylene Glycole) with the molecular weight of 600, 1000 and 3400, were used as chemical binders for the suspension solution. The organic additive PEG showed better effects to the properties of YBCO superconductor wire. The PEG improved the adhesion between superconductor particles and suppressed the crack on the surface, which enhanced the surface uniformity and density of YBCO deposited film. It was found that acetone suspension solution showed better deposition properties than the others. The samples fabricated in the solution with the additive, 8 vol.% of 1% PEG(1000), showed the highest critical current density measured as $2300{\sim}2400\;Acm^2$ at 77 K, 0 T.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.527-531
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• 2007

The classical continuum theory-based thin film model is independent of their size and the surface effect can be ignored. But the surface to bulk ratio becomes very large in nano-size structures such as nano film, nano wire and nano beam. In this case, surface effect plays an important role and its contribution of the surface effect must be considered. Molecular dynamics simulation has been a conventional way to analyze these ultra-thin structures but structures in the range between submicro and micro are difficult to analyze by classical molecular dynamics due to the restriction of computing resources and time. Therefore, in present study, the continuum-based method is considered to predict the overall physical and mechanical properties of the structures in nano-scale, especially, for the thin-film. The proposed continuum based-thin plate finite element is efficient and reliable for the prediction of nano-scale film behavior.