• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.121-121
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• 2011

Graphene formed by chemical vapor deposition was exposed to the various plasmas of Ar, O2, N2, and H2 to examine its effects on the bonding properties of graphene to metal. Upon the Ar plasma exposure of patterned graphene, the subsequently deposited metal electrodes remained intact, enabling successful fabrication of field effect transistor (FET) arrays. The effects of enhancing adhesion between graphene and metals were more evident from O2 plasmas than Ar, N2, and H2 plasmas, suggesting that chemical reaction of O radicals induces hydrophilic property of graphene more effectively than chemical reaction of H and N radicals and physical bombardment of Ar ions. From the electrical measurements (drain current vs. gate voltage) of field effect transistors before and after Ar plasma exposure, it was confirmed that the plasma treatment is very effective in controlling bonding properties of graphene to metals accurately without requiring buffer layers.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2006년도 제31회 학술논문발표회 초록집
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• pp.128-128
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• 2006

• Macromolecular Research
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• 제13권1호
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• pp.2-7
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• 2005

A series of ethylene polymerization catalysts based on tridentate bis-imine ligands coordinated to iron and cobalt was reported. The ligands were prepared through the condensation of sterically bulky anilines with allyloxy-and benzyloxy-substituted 2,6-acetylpyridines. The pre-catalyst complexes were penta-coordinate species of the general formula $\{[(ArN=C(Me))_2(4-RO-C_5H_3N)]MCl_2\}$ (Ar=ortho dialkyl-substituted aryl ring; R=allyl, benzyl; M=Fe, Co). In the presence of ethylene and methyl alumoxane cocatalysts, these complexes were active for the polymerization of ethylene, with activities lower than those of metal complexes of the general formula $\{[(2-ArN=C(Me)_2C_5H_3N]MCl_2\}$ (Ar=ortho dialkyl-substituted aryl ring; M=Co, Fe), containing no substituents in 2,6-acetylpyridine ring. The effects of the catalyst structure and temperature on the polymerization activity, thermal properties, and molecular weight were discussed.

• 한국화재소방학회논문지
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• 제18권2호
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• pp.12-19
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• 2004

지구 환경 보호를 고려한 불활성가스계의 혼합물인 IG-541소화제가 개발되었다. 소화제는 물성에 의한 특성 및 효율성, 환경에 미치는 영향뿐만 아니라 안정성, 경제성을 고려해야한다. 이러한 불활성 가스계의 대체 소화제에 사용되는 $N_2$, Ar, $CO_2$의 순수 및 혼합물의 물성을 수집하여 비교하였다. 불활성 가스계 대체소화제의 물성 중 밀도, 점도, 표면장력을 온도에 대한 변화와 혼합물에서 몰 분율의 변화에 관해 비교하였다. 3성분계 혼합물 중 50% $N_2$, 40% Ar, 10% $CO_2$(mol. %)의 조성인 혼합물에서 밀도가 높고, 점도가 낮으며, 표면장력이 순수 성분 보다 높지 않아 소화제로서 유리하다.

• 대한소아치과학회지
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• 제34권4호
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• pp.551-559
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• 2007

하악골 성장을 평가하는 데 경추골 성숙도가 수완부골 성숙도만큼 유용한가 규명하고자 본 연구를 시행하였다. 정상교합을 가진 만 8세$\sim$만 16세 여성 292명을 연구대상으로 하여 진단석고모형, 측모두부규격방사선사진, 그리고 수완부방사선사진을 이용하여 경추 및 수완부의 골성숙도를 비교하여 다음과 같은 결과를 얻었다. 1. 연령 증가에 따라 경추 및 수완부의 골성숙도가 일정하게 증가하였다. 2. 경추골 성숙도가 증가할수록 Ar-Go, Go-Me, N-Go, S-Gn, N-Me이 일정하게 증가하였다. 3. 수완부골 성숙도가 증가할수록 Ar-Go, Go-Me, N-Go, S-Gn이 일정하게 증가하였다. 4. 경추골 성숙도 3단계와 4단계 사이에서 Ar-Go, Go-Me, N-Go, S-Gn이 크게 증가하였고, 수완부골 성숙도 6단계와 7단계 사이에서 Go-Me, S-Gn이 크게 증가하였다. 5. Ar-Go, Go-Me, N-Go, S-Gn, N-Me은 경추 및 수완부 골성숙도와 각각 유의 한 상관성을 보였다. 이상의 결과는 하악골 성장을 평가하는 데에 경추골 성숙도가 수완부골 성숙도처럼 유용하게 사용될 수 있음을 시사한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.75-78
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• 1996

The deposition condition Gf TiN films as electrode was studied by sheet resistance, TiN depositon Thickness X-ray diffraction. TiN was made by reactively DC magnetron sputtering with varying $N_2$/Ar mixture gas and substrate temperature. After finding The deposition condition of TiN films, The samples with the structure of Cu/Ta$_2$O$_{5}$, TiN/Ta$_2$O$_{5}$Si, Cu/TiN/Ta$_2$O$_{5}$ Si were prepared and were measured I-V, C-V. As a results, it was found that when TiN was deposited in an $N_2$a results, it was found that when TiN was deposited in an $N_2$atmosphere its Sheet resistance is lower n than n V$_2$Ar mixtureixture

• Transactions on Electrical and Electronic Materials
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• 제12권4호
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• pp.144-147
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• 2011

In this work, we present a study regarding the etching characteristics on titanium nitride (TiN) thin films using an inductively coupled plasma system. The TiN thin film was etched using a $N_2/BCl_3$/Ar plasma. The studied etching parameters were the gas mixing ratio, the radio frequency (RF) power, the direct current (DC)-bias voltages, and the process pressures. The baseline conditions were as follows: RF power = 500 W, DC-bias voltage = -150 V, substrate temperature = $40^{\circ}C$, and process pressure = 15 mTorr. The maximum etch rate and the selectivity of the TiN to the $SiO_2$ thin film were 62.38 nm/min and 5.7, respectively. The X-ray photoelectron spectroscopy results showed no accumulation of etching byproducts from the etched surface of the TiN thin film. Based on the experimental results, the etched TiN thin film was obtained by the chemical etching found in the reactive ion etching mechanism.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.202-202
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• 2012

염료감응태양전지(DSSC)의 광변환 효율을 향상시키기 위하여 진공챔버에서 450도 고온에서 O2, Ar, and N2 혼합가스를 주입하여 다양한 plasma로 TiO2 박막을 처리하면서 소성시켰다. TiO2 표면을 cleaning하고 활성화함으로서 염료의 결합력을 향상시키는 것 외에 TiO2 내부의 oxygen vacancy를 변화를 관찰하였다. 실험에 사용한 박막은 glass 위에 FTO 박막을 입히고, 다공성 TiO2 나노입자 박막을 코팅하여 제조하였다(porous TiO2 나노입자(${\sim}12{\mu}m$)/FTO(Fluorine doped Tin oxide; $1{\mu}m$)/glass). 완성된 광전극에 대해서 XRD, XPS, EIS, FE-SEM 등을 이용하여 분석하였다. 또한 이렇게 전처리된 광전극을 사용한 DSSC를 제작하였다. 그리고 Solar-simulator를 통해 그 효율을 측정하여 '플라즈마환경에서 소성된 광전극에 대한 DSSC의 광변환효율에 미치는 효과'을 고찰하였다.

• Corrosion Science and Technology
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• 제13권2호
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• pp.70-80
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• 2014

Duplex stainless steels with nearly equal fraction of the ferrite(${\alpha}$) phase and austenite(${\gamma}$) phase have been increasingly used for various applications such as power plants, desalination facilities due to their high resistance to corrosion, good weldability, and excellent mechanical properties. Hyper duplex stainless steel (HDSS) is defined as the future duplex stainless steel with a pitting resistance equivalent (PRE=wt.%Cr+3.3(wt.%Mo+0.5wt.%W)+30wt.%N) of above 50. However, when HDSS is welded with gas tungsten arc (GTA), incorporation of nitrogen in the Ar shielding gas are very important because the volume fraction of ${\alpha}$-phase and ${\gamma}$-phase is changed and harmful secondary phases can be formed in the welded zone. In other words, the balance of corrosion resistance between two phases and reduction of $Cr_2N$ are the key points of this study. The primary results of this study are as follows. The addition of $N_2$ to the Ar shielding gas provides phase balance under weld-cooling conditions and increases the transformation temperature of the ${\alpha}$-phase to ${\gamma}$-phase, increasing the fraction of ${\gamma}$-phase as well as decreasing the precipitation of $Cr_2N$. In the anodic polarization test, the addition of nitrogen gas in the Ar shielding gas improved values of the electrochemical parameters, compared to the Pure Ar. Also, in the erosion-corrosion test, the HDSS welded with shielding gas containing $N_2$ decreased the weight loss, compared to HDSS welded with the Ar pure gas. This result showed the resistance of erosion-corrosion was increased due to increasing the fraction of ${\gamma}$-phase and the stability of passive film according to the addition $N_2$ gas to the Ar shielding gas. As a result, the addition of nitrogen gas to the shielding gas improved the resistance of erosion-corrosion.

• 한국표면공학회지
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• 제42권6호
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• pp.251-255
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• 2009

In this study, the plasma etching of the TaN thin film with $O_2/BCl_3$/Ar gas chemistries was investigated. The equipment for the etching was an inductively coupled plasma (ICP) system. The etch rate of the TaN thin film and the selectivity of TaN to $SiO_2$ and PR was studied as a function of the process parameters, including the amount of $O_2$ added, an RF power, a DC-bias voltage and the process pressure. When the gas mixing ratio was $O_2$(3 sccm)/$BCl_3$(6 sccm)/Ar(14 sccm), with the other conditions fixed, the highest etch rate was obtained. As the RF power and the dc-bias voltage were increased, the etch rate of the TaN thin film was increased. X-ray photoelectron spectroscopy (XPS) was used to investigate the chemical states of the surface of the TaN thin film.