• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05a
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• pp.34-37
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• 2003

본 연구는 고온초전도 coated coductors의 기판으로 cube texture된 순수 Ni 기판을 개발하기 위하여 전체 가공율과 압연율에 따른 (100) texture의 변화와 1차적으로 열처리한 기판을 다시 압연한 후 재열처리 하였을 때의 전체 가공율과 압연율에 따른 (100) texture의 변화를 GADS XRD와 SEM을 이용하여 연구하고자 하였다. 그 결과, 압연 후에는 압연율에 관계없이 비교적 약한 강도의 (220)과 (200), (111), (311) peak가 나타났는데, 4%로 압연했을 경우 (220) peak가 가장 강한 peak로 나타난 반면, 10%로 압연한 경우에는 (200) peak가 비교적 강하게 나타났다. 그러나 이를 $900^{\circ}C$에서 열처리한 후에는 (200) peak 만 뚜렷이 발달되어 나타났는데, 전체 가공율과 압연율이 높을수록 (200) peak의 강도가 높게 나타나 압연을 통하여 발달한 결정립자의 (110) 면을 따른 배열이 열처리 과정을 통하여 회전하여 (100)면을 따른 배열로 바뀌는 것으로 추측할 수 있었다. 그러나 $900^{\circ}C$에서 열처리한 두께 0.2mm 판재를 다시 0.1mm까지 4%와 10%의 압연율로 압연하고 500~$900^{\circ}C$에서 1시간동안 최종 열처리한 후에는 상대적으로 낮은 2차 가공율에 의하여 집합조직의 전체 가공율과 압연율에의 의존성이 사라지는 것으로 나타났다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.303-310
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• 2008

We fabricated hydrogenated amorphous silicon(a-Si:H) 140 nm thick film on a $180\;nm-SiO_2/Si$ substrate with an inductively-coupled plasma chemical vapor deposition(ICP-CVD) equipment at $250^{\circ}C$. Moreover, 30 nm-Ni film was deposited with a thermal-evaporator sequently. Then the film stack was annealed to induce silicides by a rapid thermal annealer(RTA) at $200{\sim}500^{\circ}C$ in every $50^{\circ}C$ for 30 minuets. We employed a four-point tester, high resolution X-ray diffraction(HRXRD), field emission scanning electron microscope(FE-SEM), transmission electron microscope(TEM), and scanning probe microscope(SPM) in order to examine the sheet resistance, phase transformation, in-plane microstructure, cross-sectional microstructure evolution, and surface roughness, respectively. We confirmed that nano-thick high resistive $Ni_3Si$, mid-resistive $Ni_2Si$, and low resistive NiSi phases were stable at the temperature of <300, $350{\sim}450^{\circ}C$, and >$450^{\circ}C$, respectively. Through SPM analysis, we confirmed the surface roughness of nickel silicide was below 12 nm, which implied that it was superior over employing the glass and polymer substrates.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.6
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• pp.296-301
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• 2013

Carbon coils could be synthesized using $C_2H_2/H_2$ as source gases and $SF_6$ as an incorporated additive gas under the thermal chemical vapor deposition system. A 304-type stainless steel was used as a substrate with nickel powders as the catalyst. The surface of the substrate was pretreated using a sand paper or a mechanical drill to enhance the production yield of the carbon coils. The characteristics of the deposited carbon nanomaterials on the substrates were investigated according to the surface state on the stainless steel substrate. The protrusion induced by the grooves on the substrate surface could enhance the formation of the carbon nanomaterials having the coils geometries. The cause for the enhancement of the carbon coils formation by the grooves was suggested and discussed with the surface energies for the interaction between as-growing carbon elements. Finally, we could obtain the massive production yield of the carbon coils by the surface pretreatment using SiC sand papers on the several tens grooved stainless steel substrate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.205-205
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• 2009

As a p-type semiconductor NiO is potential material which can be used in many application including QD-LED. NiO films were deposited on glass substrates using rf-sputtering method. The properties of resistivity, surface roughness, etc in the NiO films were investigated at different sputtering parameters. The resistivity of $l.88{\times}10^{-2}{\sim}3.71{\times}10^{-2}{\Omega}cm$ with sputtering power(80~200 watts) and change was very low. The sputtering pressure at 3~60 mTorr resulted in rather broad change ofresistivity of $0.58{\times}10^{-2}{\sim}4.67{\Omega}cm$. The oxygen content in sputtering gas was found to be very effective to control the resistivity from $2.01{\times}10^{-2}$ to $1.22{\times}10^2{\Omega}cm$ with 100~2.5% $O_2$ in Ar gas. In addition, the surface roughness showed the RMS values of 0.6~1.1 nm and the dependence on sputtering parameters was weak.

• Journal of the Korean Ceramic Society
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• v.41 no.2
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• pp.106-110
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• 2004

Nickel oxide (NiO) thin films were prepared on Si(100) substrates at room temperature by RF magnetron sputtering using a NiO target. The effects of oxygen flow ratio for the plasma gas on the preferred orientation and surface morphology of the NiO films were investigated. Highly crystalline NiO film with (100) orientation was obtained when it was deposited in pure Ar gas. For NiO film deposited in pure O$_2$ gas, on the other hand, the orientation of the film changed from (100) to (111) and its deposition rate decreased. The origin of the preferred orientation of the films was discussed. NiO films also showed different surface morphologies and roughnesses with the oxygen flow ratio.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4371-4376
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• 2011

In this work, we investigate the growth behavior of silicon oxide nanowires via a solid-liquid-solid process. Silicon oxide nanowires were synthesized at $1000^{\circ}C$ in an Ar and $H_2$ mixed gas. A pre-oxidized silicon wafer and a nickel film are used as the substrate and catalyst, respectively. We propose two distinctive growth modes for the silicon oxide nanowires that both act as a unique solid-liquid-solid growth process. We named the two growth mechanisms "grounded-growth" and "branched-growth" modes to characterize their unique solid-liquid-solid growth behavior. The two growth modes were classified by the generation site of the nanowires. The grounded-growth mode in which the grown nanowires are generated from the substrate and the branchedgrowth mode where the nanowires are grown from the side of the previously grown nanowires or at the metal catalyst drop attached at the tip of the nanowire stem.

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2431-2437
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• 2014

In this study, Ni, Ni-Cu and Ni/Cu catalysts were deposited onto C-fiber textiles via the electrophoretic deposition method, and the growth characteristics of carbon nanofibers on the deposited catalyst/C-fiber textiles were investigated. The catalyst deposition onto C-fiber textiles was accomplished by immersing the C-fiber textiles into Ni or Ni-Cu mixed solutions, producing the substrate by post-deposition of Ni onto C-fiber textiles with pre-deposited Cu, and passing it through a gas mixture of $N_2$, $H_2$ and $C_2H_4$ at $700^{\circ}C$ to synthesize carbon nanofibers. For analysis of the characteristics of the synthesized carbon nanofibers and the deposition pattern of catalysts, SEM, EDS, BET, XRD, Raman and XPS analysis were conducted. It was found that the amount of catalyst deposited and the ratio of Ni deposition in the Ni-Cu mixed solution increased with an increasing voltage for electrophoretic deposition. In the case of post-deposition of Ni catalyst onto substrates with pre-deposited Cu, both bimetallic catalyst and carbon nanofibers with a high level of crystallizability were produced. Carbon nanofibers yielded with the catalyst prepared in Ni and Ni-Cu mixed solutions showed a Y-shaped morphology.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1533-1535
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• 2002

Carbon nanotubes (CNTs) were grown with high density on a large area of Ni-coated silicon oxide substrates by using an inductively coupled plasma-chemical vapor deposition (ICP-CVD) of $C_2H_2$ at temperatures ranging from 600 to $700^{\circ}C$. The Ni catalyst was formed using an RF magnetron sputtering system with varying the operating pressure and exposure time of $NH_3$ plasma. The surface morphology of nickel catalyst films and CNTs was examined by SEM and AFM. The graphitized structure of CNTs was confirmed by Ramman spectra, SEM, and TEM. The growth of CNTs was observed to be strongly influenced by the surface morphology of Ni catalyst, which depended on the pre-treatment time and growth temperature. Dense CNTs with uniform-sized grains were successfully grown by ICP-CVD.

• Journal of Korean Vacuum Science & Technology
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• v.4 no.2
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• pp.55-60
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• 2000

Vertically aligned carbon nanotubes on nickel coated glass substrates were obtained at low temperatures below 600$\^{C}$ by plasma enhanced hot filament chemical vapor deposition where acetylene gas was used as the carbon source and ammonia gas was used as the dilution gas and catalyst. The diameters of the nanotubes decreased from 96 m to 41 m as NH$_3$/C$_2$H$_2$ ratio increased from 2:1 to 5:1. Total flow rate of input gases with constant NH$_3$/C$_2$H$_2$ ratio did not change the diameter of carbon nanotubes. No growth of the carbon nanotubes was observed with only C$_2$H$_2$ nor N$_2$ instead of NH$_2$. G line and D line in Raman spectra were observed, which implies that there were many structural defects in carbon nanotubes.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.5
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• pp.245-248
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• 2010

Sn doped $In_2O_3$ (ITO) and ITO/Ni/ITO (INI) multilayer films were deposited on the glass substrates with a reactive magnetron sputtering system without intentional substrate heating and then the influence of the Ni interlayer on the methanol gas sensitivity of ITO and INI film sensors were investigated. Although both ITO and INI film sensors have the same thickness of 100 nm, INI sensors have a sandwich structure of ITO 50 nm/Ni 5 nm/ITO 45 nm. The changes in the gas sensitivity of the film sensors caused by methanol gas ranging from 100 to 1000 ppm were measured. It is observed that the INI film sensors show the higher sensitivity than that of the ITO single layer sensors. Finally, it can be concluded that the INI film sensor have the potential to be used as improved methanol gas sensors.