• Proceedings of the Korean Vacuum Society Conference
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• 2006.02a
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• pp.186-186
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• 2006

• Progress in Superconductivity and Cryogenics
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• v.13 no.4
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• pp.5-9
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• 2011

We have fabricated the superconducting $MgB_2$/carbon fiber by physical vapor deposition method. Mg (Magnesium) and B (Boron) were simultaneously deposited on the carbon fiber using the RF-sputtering and thermal evaporation, respectively. To ensure the relatively high vapor pressure of Mg at the growth region and the subsequent phase stability of $MgB_2$ at the deposition temperature, inverted funnel-like guide made of Mg-foil was employed while one side of the guide were open for the sputtered B flux. Mg vapor pressure should be controlled precisely to secure the complete reaction. The $MgB_2$/carbon fiber showed a uniformly deposited thin layer with dense and well-formed grains. The $MgB_2$/carbon fibers in this study showed $T_c$~37.5K, $J_c$ ~ $2{\times}10^4\;A/cm^2$ in the 20K, 0T.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.297-300
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• 1997

In this study, The PVDF thin film was fabricated on the one method of dry-process the physical vapor deposition method, applied electric field, and evaporation control in $\beta$-PVDF thin film preparation. A study on the electric-field-phase change of PVDF thin film in physical vapor deposition using the polymer deposition apparatus which are manufactured for oneself. In the analysis of Fourier-Transform Infrared spectra, according to increasing of electric field intensity, the 510$cm^{-1}$ / peak and 1273$cm^{-1}$ / peak which are showed in $\beta$-PVDF increase, on the contrary the 530$cm^{-1}$ / peak and 977$cm^{-1}$ / peak which are showed in $\alpha$-PVDF decrease.

• Electrical & Electronic Materials
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• v.10 no.3
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• pp.217-225
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• 1997

In this study, the PVDF organic thin film was fabricated by the physical vapor deposition method to be dry-process. The distance of heat source and substrate was 5[cm] and the temperature of substrate was 30[.deg. C], when the pressure had reached 2.0 x 10$^{-5}$ [Torr], the temperature of heat source was reached to 285[.deg. C] to heat at 6-8[.deg. C/min] rate, the shutter was opened and deposition was started. TG-DTA(Thermogravimetric-Differential Thermal Analysis) spectrum of PVDF pellets showed that endothermic peak arose at 170[.deg. C] and exothermic peak at 524[.deg. C], but that of thin PVDF film showed that endothermic peak arose at 145[.deg. C] and exothermic peak at 443[.deg C]. The current density was increased linearly with increasing voltage but increased nonlinearly with higher electric field than 250[kV/cm] and activation energy was about 0.667[eV] at the temperature of 30-90[.deg. C].

• Journal of the Korean Vacuum Society
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• v.8 no.3A
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• pp.194-200
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• 1999

In this paper studied was the piezoelectric properties of the $\beta$-PVDF organic thin films prepared by physical vapour deposition method. The molecular orientation of organic thin films was controlled by the application of an electric field and variation of substrate temperature during the evaporation process. Optimum conditions of manufacturing $\beta$-PVDF organic thin film by physical vapor deposition method is to keep at the substrate temperature of $80^{\circ}C$, at the applied electric field of 142.8 kV/cm. The voltage output coefficient increased from 1.39 to 7.04V increasing the force moment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.367-370
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• 2000

In this study, thin films of 70/30 and 80/20 mol% P(VDF-TrFE) copolymers were fabricated by physical vapor deposition method. In order to determine the optimum deposition condition, the copolymer thin films were fabricated in the heating temperature of 260$^{\circ}C$, 280$^{\circ}C$, and 300$^{\circ}C$. The deposition rate was measured in a real time by thickness monitor. The surface image of prepared thin films was analyzed by using AFM. From the results of TG-DTA,70/30 and 80/20 mol% P(VDF-TrFE) copolymers were observed the Curie transition point below the melting point. As the results of AFM and FT-IR analysis, we determined that the optimum deposition temperature was 300$^{\circ}C$.

• Transactions on Electrical and Electronic Materials
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• v.14 no.3
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• pp.148-151
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• 2013

The control of Ga doping in ZnO nanowires (NWs) by physical vapor deposition has been implemented and characterized. Various Ga-doped ZnO NWs were grown using the vapor-liquid-solid (VLS) method, with Au catalyst on c-plane sapphire substrate by hot-walled pulsed laser deposition (HW-PLD), one of the physical vapor deposition methods. The structural, optical and electrical properties of Ga-doped ZnO NWs have been systematically analyzed, by changing Ga concentration in ZnO NWs. We observed stacking faults and different crystalline directions caused by increasing Ga concentration in ZnO NWs, using SEM and HR-TEM. A $D^0X$ peak in the PL spectra of Ga doped ZnO NWs that is sharper than that of pure ZnO NWs has been clearly observed, which indicated the substitution of Ga for Zn. The electrical properties of controlled Ga-doped ZnO NWs have been measured, and show that the conductance of ZnO NWs increased up to 3 wt% Ga doping. However, the conductance of 5 wt% Ga doped ZnO NWs decreased, because the mean free path was decreased, according to the increase of carrier concentration. This control of the structural, optical and electrical properties of ZnO NWs by doping, could provide the possibility of the fabrication of various nanowire based electronic devices, such as nano-FETs, nano-inverters, nano-logic circuits and customized nano-sensors.

• Journal of the Korean Ceramic Society
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• v.56 no.3
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• pp.317-324
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• 2019

Cr-diamond-like carbon (Cr-DLC) films were deposited using a hybrid method involving both physical vapor deposition and plasma-enhanced chemical vapor deposition. DLC sputtering was carried out using argon and acetylene gases. With an increase in the DC power, the Cr content increased from 14.7 to 29.7 at%. The Cr-C bond appeared when the Cr content was 17.6 at% or more. At a Cr content of 17.6 at%, the films showed an electrical conductivity of > 363 S/cm. The current density was 9.12 × 10^-2 ㎂/㎠, and the corrosion potential was 0.240 V. Therefore, a Cr content of 17.6 at% was found to be optimum for the deposition of the Cr-DLC thin films. The Cr-DLC thin films developed in this study showed high conductivity and corrosion resistance, and hence, are suitable for applications in separators.

• Journal of the Korean Ceramic Society
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• v.43 no.5 s.288
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• pp.299-303
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• 2006

In this paper, anode supported SOFC with columnar structured YSZ electrolyte was fabricated via Electron Beam Physical Vapor Deposition (EBPVD) method. Liquid condensation process was employed for the preparation of NiO-YSZ substrate and the high power electron beam deposition method was used for the deposition of YSZ electrolyte film. Double layered cathode with LSM-YSZ and LSM was printed on electrolyte via screen-printing method and fired at $1150^{\circ}C$ in air atmosphere for 3 h. The electrochemical performance and the long-term stability of $5{\times}5cm^2$ single cell were investigated with DC current-voltage characteristics and AC-impedance spectroscopy. According to the investigation, $5{\times}5cm^2$ sized unit cell showed the maximum power density of around $0.76W/cm^2$ at $800^{\circ}C$ and maintained the stable performance over 400 h.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.791-794
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• 2003

DLC thin films were prepared by microwave plasma-enhanced chemical vapor deposition method on silicon substrates using methane ($CH_4$) and hydrogen ($H_2$) gas mixture. The negative DC bias ($-450V{\sim}-550V$) was applied to enhance the adhesion between the film and the substrate. The films were characterized by Raman spectrometer. The surface morphology was observed by an atomic force microscope (AFM). And also, the friction coefficients were investigated by AFM in friction force microscope (FFM) mode, which were compared with the pin-on-disc (POD) measurement.