• 한국결정학회지
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• 제12권4호
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• pp.222-226
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• 2001

$Ni(L)_4(NCS)_2$(1) (L=2-ethylimidazole)착물의 합성하고 단결정 구조를 규명하였다. 이 착물은 정방정계, 공간군 P4nc a=10.587(2), $c=12.927(3){\AA}$, $V=1448.9(4){\AA}$, Z=2로 결정화되었으며 676개의독립적인 회절반점에 대한 최종 신뢰도 인자 $R_1$ 및$wR_₂$값은 각각 0.0581 및 0.1675이었다. 이 착물의 결정 구조는 Ni(II) 금속 원자에 4개의 2-ethylimidazole리간드의 질소 원자가 xy 평면에 배위되고 있고. 2개의 isothiocyanate 리간드의 질소원자 z축 방향에서 트란스 형태뢰 배위되어 균일한 팔면체 구조의 단핵 착물을 형성한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1220-1221
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• 2008

Submicron-sized conical-type tungsten(W) field-emitters based on carbon nanotubes(CNTs) are fabricated with the configuration of CNTs/catalyst(Ni)/buffer(Al/Ni/TiN)/W-tip. This study focuses on elucidating how the Al/Ni/TiN stacked buffer layer affects the structural properties of CNTs and the electron-emission characteristics of CNT-emitters. Field-emission scanning electron microscopy(FESEM), high-resolution transmission electron microscopy(HRTEM), and x-ray photoelectron spectroscopy(XPS) are used to monitor the nanostructures, surface morphologies, chemical bonds of all the catalysts and CNTs grown. The crystalline structure of CNTs is also characterized by Raman spectroscopy. Furthermore, the measurement of field-emission characteristics for the field-emitters fabricated shows that the emitter using the Al/Ni/TiN stacked buffer reveals the excellent performances.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.275-281
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• 2011

Solar reforming of methane with $CO_2$ was successfully tested with a direct irradiated absorber on a parabolic dish capable of $5kW_{th}$ solar power. The new type of catalytically activated metallic foam absorber was prepared, and its activity was tested. Ni was applied as the active metal on the gamma - alumina coated Ni metal foam for the preparation of the catalytically-activated metal foam layer. Compared to conventional direct irradiation of the catalytically-activated ceramic foam absorber, this new metallic foam absorber is found to exhibit a superior reaction performance at the relatively low insolation or at low temperatures. In addition, unlike direct irradiation of the catalytically-activated ceramic foam absorber, metallic foam absorber has better thermal resistance, which prevents the emergence of cracks caused by mechanical or thermal shock. The total solar power absorbed reached up to 2.1kW and the maximum $CH_4$ conversion was almost 40%.

• 센서학회지
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• 제22권5호
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• pp.327-332
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• 2013

Nickel oxide films using RF sputter was formed on the $SiO_2/Si$ substrate at the room temperature controlled with water circulation system. The feasibility of nickel oxide film as a bolometric material was demonstrated. GIXRD spectrum on NiO(111), NiO(200), and NiO(220) orientation expected as the main peaks were appeared in the grown nickel oxide films. The typical resistivity acquired at the RF power of 100W was about $34.25{\Omega}{\cdot}cm$. And it was reduced to $18.65{\Omega}{\cdot}cm$ according to the increase of the RF power to 400W. The TCR of fabricated micro-bolometer with the resistivity of $34.25{\Omega}{\cdot}cm$ was $-2.01%/^{\circ}C$. The characteristics of fabricated nickel oxide film and micro-bolometer were analyzed with XRD pattern, resistivity, TCR, and SEM images.

• 열처리공학회지
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• 제32권4호
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• pp.161-167
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• 2019

Impact toughness and fracture behavior were studied in five kinds of non-heat treating steels containing bainite; standard(0.25C-1.5Mn-0.5Cr-0.2Mo-0.15V), high V(0.3V), Ni(0.5Mn-2Ni), W(0.4W instead of Mo), and high C-Ni(0.35C-0.5Mn-2Ni) steels. The good hardness and impact toughness balance was exhibited in the $1100^{\circ}C$-rolled condition, while the impact toughness was deteriorated due to coarse grained microstructure in the $1200^{\circ}C$-rolled condition. The impact toughness decreased with increasing the hardness in all steels studied. The fracture behavior was also basically identical, that is, the fracture area was divided into 3 zones; shear and fibrous zone, fracture transition zone with ductile dimples and cleavage cracks, where the cracks initiate and grow to critical size, unstable cleavage fracture propagation zone. The energy absorbed for the critical crack formation through the plastic deformation inside the plastic zone in front of the notch root contributed to a mostly significant portion of the total impact energy.

• 한국수소및신에너지학회논문집
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• 제19권5호
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• pp.423-429
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• 2008

This work was carried out to improve the performance of anodic electrocatalysts in direct ethanol fuel cell(DEFC). PtRu and $Pt_5Ru_4M$(M= Ni, Sn, Mo and W) electrocatalysts were prepared by using a $NaBH_4$ reduction method. Alloy crystal structure and particle size of electrocatalysts were characterized by X-ray diffraction(XRD) and transmission electron microscopy(TEM). The XRD analysis of the electrocatalysts revealed that the face-centered cubic(fcc) peaks shifted to slightly higher diffraction angles when third metals were added. Average size of the uniform particles was observed to be approximately $3{\sim}3.5\;nm$ from the TEM image. The electrochemical measurements were carried out in the solution 1M $H_2SO_4$ and 1M $C_2H_5OH$ at room temperature. Cyclic-voltammogram results showed that $Pt_5Ru_4W$ electrocatalyst exhibited much higher current density for ethanol oxidation of $2.73\;mA/cm^2$ than PtRu electrocatalyst of $0.73\;mA/cm^2$.

• 한국초전도ㆍ저온공학회논문지
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• 제8권3호
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• pp.9-12
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• 2006

Batch type co-evaporation EDDC (Evaporation using Drum in Dual Chambers) system was recently manufactured to fabricate 100m - long SmBCO superconducting coated conductor. As a preliminary study before the fabrication of long tape. short CC samples have been fabricated using the EDDC system and their crystal texture and $I_c$ properties were investigated. $1.2 {\mu}m$-thick SmBCO layers were deposited on $CeO_2/YSZ/CeO_2$ buffered Ni-W tapes. $I_c$ of 128A/cm-w and corresponding $J_c$ of $1.1 MA/cm^2$ at 77K in self-field were obtained for SmBCO CC tape. In-field property of SmBCO CC was confirmed to be better than that of YBCO deposited by PLD.

• 한국재료학회지
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• 제14권8호
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• pp.573-578
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• 2004

Newly developed silicide materials for ULSI should have the appropriate electrical property of low resistant as well as process compatibility in conventional CMOS process. We prepared $NiCoSi_x$ silicides from 15 nm-Co/15 nm-Ni/Si structure and performed contact dry etch process to confirm the dry etch stability and compatibility of $NiCoSi_x$ layers. We dry etched the photoresist/SiO/silicide/silicon patterns with $CF_4\;and\;CHF_3$ gases with varying powers from 100 to 200 W, and pressures from 45 to 65 mTorr, respectively. Polysilicon and silicon active layers without silicide were etched $0\sim316{\AA}$ during over etch time of 3min, while silicon layers with proposed $NiCoSi_x$ silicide were not etched and showed stable surfaces. Our result implies that new $NiCoSi_x$ silicides may replace the conventional silicides due to contact etch process compatibility.

• Journal of Welding and Joining
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• 제20권6호
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• pp.59-59
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• 2002

Sn-Ag-Cu solder is known as most competitive in many kinds of Pb-free solders. In this study, effects of solderability with plated layers such as Cu, Cu/Sn, Cu/Ni and Cu/Ni/Au were investigated. Sn-3.5Ag-0.7Cu solder balls were reflowed in commercial reflow machine (peak temp. : 250℃ and conveyer speed : 0.6m/min). In wetting test, immersion speed was 5mm/sec., immersion time 5sec., immersion depth 4mm and temperature of solder bath was 250℃. Wettability of Sn-3.5Ag-0.7Cu on Cu, Cu/Sn (5㎛), Cu/Ni (5㎛), and Cu/Ni/Au (5㎛/500Å) layers was investigated. Cu/Ni/Au layer had the best wettability as zero cross time and equilibrium force, and the measured values were 0.93 sec and 7mN, respectively. Surface tension of Sn-3.5Ag-0.7Cu solder turmed out to be 0.52N/m. The thickness of IMC is reduced in the order of Cu, Cu/Sn, Cu/Mi and Cu/Ni/Au coated layer. Shear strength of Cu/Ni, Cu/Sn and Cu was around 560gf but Cu/Ni/Au was 370gf.

• 소성∙가공
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• 제26권4호
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• pp.216-221
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• 2017

Recently, interest in multifunctional energetic structural materials (MESMs) has grown due to their multifunctional potential, especially in military applications. However, there are few studies about extrinsic factors that govern the reactivity of MESMs. In this paper, a shock compaction process was performed on the nano Ni/Al-mixed powder to investigate the effect of particle size on the shock reaction condition. Additionally, heating the statically compacted specimen was also performed to compare the mechanical properties and microstructure between reacted and unreacted material. The results show that the agglomerated structure of nanopowders interrupts the reaction by reducing the elemental boundary. X-ray diffraction analysis shows that the NiAl and $Ni_3Al$ intermetallics are formed on the reacted specimen. The microhardness results show that the $Ni_3Al$ phase has a higher hardness than NiAl, but the portion of $Ni_3Al$ in the reacted specimen is minor. In conclusion, using Ni/Al composites as a reactive material should focus on energetic use.