• 한국진공학회지
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• 제1권1호
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• pp.106-114
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• 1992

여러 조성의 Co-Ni 합금과 Au-Cu 합금에 대하여 XPS와 SIMS 분석방법을 사용하 여 표면분석의 정량화 연구를 수행하였다. XPS의 경우 Co-Ni 합금에 대하여는 수정 없이 고순도 시료만으로 1~2% 상대오차 범위 내에서 정량분석이 가능하였고, Au-Cu 합금의 경 우에는 고순도 시료만을 표준시료로 사용하여서는 정량 분석이 불가능하였고 실험적인 수정 인자를 사용한 경우 1~2% 상대오차로 정량분석이 가능하였다. Au-Cu 합금의 경우 여러 조성이 표준시료가 없는 경우 이론적인 수정인자를 사용하는 경우 10%의 상대오차로 정량 분석이 가능하였다. Co-Ni 합금을 SIMS 분석하였을 때 Co와 Ni의 이차이온 세기의 비가 넓은 농도 범위에서 각 성분의 농도의 비와 직선관계를 가져 SIMS에 의한 합금의 정량분석 이 가능하였다. 또한 VAMAS-SCA Japan Project의 XPS 공동분석의 예비 결과도 주어져 있다.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.2019-2024
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• 2014

NiCu alloys have been suggested as potential candidates for catalysts in glucose oxidation. In this study, NiCu alloys with different compositions were prepared on a glassy carbon substrate by changing the electrodeposition potential to examine the effect of Ni/Cu ratios in alloys on catalytic activity toward glucose oxidation. Cyclic voltammetry and chronoamperometry showed that NiCu alloys had higher catalytic activity than pure Ni and Cu catalysts. Especially, Ni59Cu41 had superior catalytic activity, which was about twice that of Ni at a given oxidation potential. X-ray analyses showed that the oxidation state of Ni in NiCu alloys was increased with the content of Cu by lattice expansion. Ni components in alloys with higher oxidation state were more effective in the oxidation of glucose.

• 한국진공학회지
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• 제6권S1호
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• pp.70-74
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• 1997

The study of the thickness dependence of the electron energy structure of Fe, Ni, Ti and Zr sublayers in Ni/Ti and Fe/Zr multilayers by using the experimental and computer simulated optical spectroscopy has been performed. A series of Ni/Ti and Fe/Ze multiayered films (MLF) with a bilayer period of 0.5 - 30 nm and constant (Ni/Ti) / different (Fe/Zr) sublayer thickness ratios were prepared by using computer-controlled double-pair target face-to-face sputtering onto a glass substrate at room temperature (RT) Computer simulation of the resulting optical properties of these MLF was carried out by solving of multireflection problem with a matrix method assuming either "sharp" interfaces resulting in rectangular depth profiles of the components or "mixed" (alloy-like) interfaces of variable thickness between pure-metal sublayers. Optical constants of pure bulk metals as well as equiatomic alloy interfaces were employed in these simulations. It was shown that the difference between experimental and simulated optical properties of the investigated MLF increases with decrease in sublayer thickness. This result allows to conclude that the electronic structures of sublayers below 4-5 nm thickness in mlf differ from the corresponding bulk metals.ponding bulk metals.

• Advances in nano research
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• 제2권2호
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• pp.77-88
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• 2014

Solvothermal treatment of late transition metal acetylacetonates in a novel medium composed either of pure acetophenone or acetophenone mixtures with amino alcohols offers a general approach to uniform hydrophilic metal nanoparticles with high crystallinity and low degree of aggregation. Both pure metal and mixed-metal particles can be accesses by this approach. The produced materials have been characterized by SEM-EDS, TEM, FTIR in the solid state and by Nanoparticle Tracking Analysis in solutions. The chemical mechanisms of the reactions producing nanoparticles has been followed by NMR. Carrying out the process in pure acetophenone produces palladium metal, copper metal with minor impurity of $Cu_2O$, and NiO. The synthesis starting from the mixtures of Pd and Ni acetylacetonates with up to 20 mol% of Pd, renders in minor yield the palladium-based metal alloy along with nickel oxide as the major phase. Even the synthesis starting from a mixed solution of $Cu(acac)_2$ and $Ni(acac)_2$ produces oxides as major products. The situation is improved when aminoalcohols such as 2-aminoethanol or 2-dimethylamino propanol are added to the synthesis medium. The particles in this case contain metallic elements and pairs of individual metals (not metal alloys) when produced from mixed precursor solutions in this case.

• 한국생산제조학회지
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• 제25권5호
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• pp.329-337
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• 2016

The demand for the eco-friendly vehicles is skyrocketing because of the increasing $CO_2$ emissions and global warming. In the industrial field, the battery process, a core part of an eco-friendly vehicle, is drawing increased attention; its weight lightening as well as high energy density are becoming increasingly important. In this study, pure Ni plates that were used as the battery pole plate were welded using the laser. The lab joint welding was conducted on ten pure Ni plates at a laser power of 1900 W and a feed speed of 2.8-3.4 m/min. As observed in the experiment, a faster feed speed reduced the bead width, but the laser did not penetrate all ten specimen plates. In addition, pores were trapped when protective gas was used, but they were not trapped when the welding was conducted in atmospheric condition.

• 대한화학회지
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• 제25권4호
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• pp.236-245
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• 1981

순수한 $SrTiO_3$ 및 Ni 도프된 $SrTiO_3$ 단결정을 산화하여 700∼$1200^{\circ}C$ 및 $10^{-8}\;{\sim}\;10^{-1}$ atm의 온도 및 산소압력에서 산소압력의 함수로서 전기전도도를 측정하였다. 일정한 산소압력에서 전기전도도 값을 온도의 역수에 대하여 도시한 결과 직선관계를 나타내었으며 그 기울기로 부터 구한 활성화 에너지 값들은 순수한 $SrTiO_3$,에 대하여 1.34eV이며 Ni-doped $SrTiO_3$에 대하여 1.06eV이다. 일정한 온도에서 전기전도도 값을 산소분압에 대하여 도시한 결과 주어진 온도 범위에서 전기전도도의 산소압력 의존도가 -1/5.6${\sim}$-1.62로 나타났다. 실험치와 이론적으로 해석한 전기전도도의 산소 압력 의존성으로 부터 산소공위결합모델을 산화된 $SrTiO_3$와 Ni-doped $SrTiO_3$ 단결정에 이용할 수 있음을 알게 되었다. 주어진 온도 및 산소압력 범위에서 전기전도 메카니즘이 각각 제안되었다.

• 한국표면공학회지
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• 제37권1호
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• pp.28-39
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• 2004

The effect of trace metallic additives on microstructure, surface appearance and hardness of zinc electrodeposits was investigated by using sulfate bath and flow cell system. The preferred orientation of Zn deposit with Fe additive was (103)(104)+(002) mixed texture and that of Zn deposits with both Fe-Ni and Fe-Co additives was (10 1), while Zn deposits with Fe-Cr additives had (002) preferred orientation. The surface morphology of the zinc deposits was closely related to the preferred orientation of the deposits. The glossiness of Zn deposit with Fe-Ni additives was higher than that of pure Zn deposit, while the glossiness of Zn deposits with both Fe-Co and Fe-Cr additives was lower than that of pure Zn deposit. The hardness of Zn deposits with both Fe-Ni and Fe-Co additives was noticeably higher than that of Zn-Fe deposit, while that of Zn deposit with Fe-Cr additives was similar to that of Zn-Fe deposit.

• 한국표면공학회지
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• 제32권2호
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• pp.157-164
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• 1999

In this study the effect of nickel addition on the coating weight of mini-mill steels containing silicon has been studied. It is shown that the pure zinc accelerated growth of the alloy layers occurred by a rapid growth of the zeta phase at 0.06%Si. The addition of 0.06%Ni to a pure zinc bath was found to be very effective in reducing the coating weight and promoting preferential development of the delta phase. The coating obtained by immersion in the Zn-Ni bath shows the presence of a nickel-rich region between the zeta phase and the eta phase. It is suggested that nickel prevents the rapid growth of the zeta phase due to the formation of the Zn-Ni-Fe ternary compound, which may act as a barrier to inward diffusion of zinc or iron at the zeta-eta boundary.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.139.1-139.1
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• 2016

Multiferroic materials are of great interest because of its potential applications in the design of devices combining magnetic, electronic and optical functionalities. Among various multiferroic materials, $BiFeO_3$(BFO) is known to be one of the intensively focused mainly due to the possibility of multiferroism at device working temperature (> $200^{\circ}C$). However, leakage current and weak polarization resulting from oxygen deficiency and crystalline defect should be resolved. Furthermore the magnetic ordering of pure BFO mainly prefers to have antiferromagnetic coupling. Up to now many attempts have been performed to improve the ferromagnetic and the ferroelectric properties of BFO by doping. In this work, we investigated the effects of Ni substitution on the multiferroism of bulk BFO. Four BFO samples (a pure BFO and three Ni-doped BFO's; $BiFe_{0.99}Ni_{0.01}O_3$, $BiFe_{0.98}Ni_{0.02}O_3$ and $BiFe_{0.97}Ni_{0.03}O_3$) were synthesized by the standard solid-state reaction and rapid sintering technique. The XRD results reveal that Ni atoms are substituted into Fe-sites and give rise to phase transition of cubic to rhombohedal. By using vibrating sample magnetometer and standard ferroelectric tester, the multiferroic properties at room temperature were characterized. We found that the magnetic moment of Ni-doped BFO turned out to be maximized for 3% of Ni dopant.

• Advances in environmental research
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• 제3권1호
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• pp.71-86
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• 2014

Macronutrients ($Na^+$, $K^+$, $Ca^{2+}$, $Mg^{2+}$), yield and yield components, bioaccumulation and translocation of metal in plant parts of three Vigna species (V. cylindrica, V. mungo, V. radiata) were evaluated at 0, 50, 100 and $150mgkg^{-1}$ soil of Nickel (Ni). A marked inhibition (p < 0.001) in the distribution of various macronutrients was noticed in these Vigna species except for $Mg^{2+}$ content of the shoot and leaves. Similarly, all species retained more $Ca^{2+}$ in their roots (p < 0.05) as compared to the aerial tissues. Ni induced a drastic decline (p < 0.001) for various yield and yield attributes except for 100 seed weight. Toxicity and accumulation of Ni in plant tissues considerably increased in a concentration dependent manner. Vigna species signify an exclusion approach for Ni tolerance as both bioaccumulation factor (BF) and translocation factor (TF) were less than 1.0. The Ni content of plants being root > shoot > leaves > seeds. Scoring for percentage stimulation and inhibition (respective to control) at varying levels of Ni revealed tolerance of the species in an order of V. radiata > V. cylindrica > V. mungo. The acquisition of Ni tolerance in V. radiata seems to occur through an integrated mechanism of metal tolerance that includes sustainable macronutrients uptake, stronger roots due to greater deposition of $Ca^{2+}$in the roots, restricted transfer of Ni to above ground tissues and seeds as well as exclusion capacity of the roots to bind appreciable amount of metal to them. Thus, metal tolerant potential of V. radiata could be of great significance to remediate metal contaminated soil owing lesser impact of Ni on macro-nutrients, hence the yield.