• Applied Science and Convergence Technology
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• v.27 no.2
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• pp.38-41
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• 2018

We demonstrate the growth of a sheet-like ZnO membrane on ZnO nano rod layers. The growth process is composed of 3 steps of ZnO seed formation, ZnO nano rod growth and sheet-like ZnO membrane formation on those nano rods. To confirm the fundamental growth mechanism, the lattice structures of each step were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM) measurement. Analysis of the relation between the texture coefficient and the surface shape of the ZnO membrane on the ZnO nano rods shows that the surface morphology of ZnO nano structures can be controlled using the temperature of the growing solution and the concentration of the chemical solution.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.575-575
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• 2012

Synthesis of novel two dimensional materials has gained tremendous attention recently as they are considered as alternative materials for replacing graphene that suffers from a lack of bandgap, a property that is essential for many applications. Single layer molybdenum disulfide ($MoS_2$) has a direct bandgap (1.8eV) that is promising for use in next-generation optoelectronics and energy harvesting devices. We have successfully grown high quality single layer $MoS_2$ by a facile vapor-solid transport route. As-grown single layer $MoS_2$ was carefully characterized by using X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy and electrical transport measurement. The results indicate that a high quality single layer $MoS_2$ can be successfully grown on silicon substrate. This may open up great opportunities for the exploration of novel nanoelectronic devices.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.34-35
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• 2014

탄소는 부식되지 않고 친환경적이며 물리화학적 안정성 및 내마모성 등 많은 장점을 가지고 있어 많은 연구들이 진행 되고 있다. 하지만 탄소 박막은 전도도가 낮은 단점을 가지고 있다. 본 연구에서는 탄소 박막의 전도성과 플라즈마 변수와의 상관관계를 규명 하고자 하였다. 박막의 특성은 X-ray Diffraction (XRD), Hall measurement, Contact angle, Raman spectroscopy 등의 분석기기를 사용하여 측정하였고 그 결과 DC보다 Pulse DC를 사용할 때 더 좋은 전기적 특성을 나타내었다.

• Transactions of the Korean hydrogen and new energy society
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• v.12 no.2
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• pp.121-128
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• 2001

In order to study the relation between expansion of the specimen and the hydrogen absorption rate, thin palladium plates with cold rolling were used. Thin palladium plates were hydrogenated in the 0.1mol $H_2SO_4$ electrolyte by electrochemical method. The expansion behavior on hydrogen absorbing can be obtained by X-ray diffraction analysis and by micrometer measurement It is noted that the expansion rate of Palladium specimens in thickness direction is larger than in length and width direction. The lattice constants increase quickly with increasing hydrogen absorbing rate up to 0.5, but above the rate they keep constant. Also the clues for plastic deformation, such as slip lines and voids, were observed in abundantly even though the plates were hydrogenated once.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.397-400
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• 1996

We investigated electric and dielectric properties of MIM device using Maleate Copolymer LB films. The thickness of maleate copolymer LB film by ellipsometry measurements and X-ray diffraction pattern was about 27~30[ ]. The maleate copolymer 13 film have the property of insulator like organic ultra-thin film. The electric conduction was Schottky current measured by I-V characteristics, and the conductivity was 10$^{-15}$ ~10$^{-14}$ [S/cm]. Dielectric constant was about 5.0~6.0 by various measurement: I-V, frequency-depenent dielectric properties. Schottky barrier was about 0.9 ~1.0(eV). By relation between log I and 1/T, activation energy baa 0.74(eV). Frequency-depenent dielectric properties wart orientational polarization by the dipole.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.164-168
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• 1996

The relation between crystallinity and thermal history in low density polyethylene thin films and their effect on electric conduction phenomena and dielectric breakdown was studied. The low density polythylene thin films obtained by the solution growth method heat-treated at 140[$^{\circ}C$] for 2 h and subsequently cooling to various ways. The degree of crystallinity was estimated by the X-ray diffraction measurement for the specimen of slowly cooling, ICE quenching and liquid nitrogen quenching. The result shows that the crystallinity decreases become faster as the cooling speed increased, and that conduction phenomenon is governed by the space charge limited current in high field. It was found that the dielectric breakdown field increases with an increase in cooling speed and test number in self-healing breakdown method.

• Journal of the Korean Ceramic Society
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• v.23 no.4
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• pp.78-84
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• 1986

Zirconium acetate solution which was obtained from $ZrOCl_2$.$8H_2O$ was condensed polymerized and drawn to fibers by pulling method. Drawn gel fibers fired at 130$0^{\circ}C$ were short porous and mechanically weak. But addition of CaO about 13m/o caused the fibers to have the cubic structure and relatively dense microstructure. In order to clarify the condition for the synthesis of zirconia fibers viscosity measurement DTA-TG analysis X-ray diffraction infrared spectroscopy, SEM and specific surface area were studied.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.9
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• pp.756-759
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• 2009

We described the growth of undoped ZnO thin films and their optical properties changing with a various growth temperature. The undoped ZnO thin films were grown on $c-Al_2O_3$ substrates using pulsed laser deposition (PLD) at room temperature, 200, 400, and $600^{\circ}C$, respectively. Field emission microscopy (FE-SEM) measurements showed that the grain size of undoped ZnO thin films are increasing as a increase of growth temperature. In addition, we were investigated that the structural and optical properties of undoped ZnO thin films by x-ray diffraction (XRD) and photoluminescence (PL) studied. Also, we could confirmed that the exciton luminescence was strongly related to charge trap by grain boundary of the samples using micro-PL measurement.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.2
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• pp.97-103
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• 2014

Phase transition properties of the copolymer films of polyvinylidene fluoride (PVDF) and trifluoroethylene(TrFE), P(VDF-TrFE), were studied with X-ray diffraction (XRD) and polarization modulated ellipsometry (PME). XRD studies on both Langmuir-Blodgett (LB) films and spin coated films exhibit conversions from ferroelectric phase to paraelectric phase at $108{\pm}2^{\circ}C$ on heating and paraelectric phase to ferroelectric phase at $78{\pm}2^{\circ}C$ on cooling. The presence of the ferroelectric-paraelectric phase transition is also confirmed by the PME technique for the first time in this study. PME was proved to be a very sensitive tool in the measurement of the structural changes at the nano-thickness films.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.9
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• pp.753-758
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• 2003

Ti films were deposited onto 100${\times}$100 mm alumina substrates using dc magnetron sputtering under the following conditions; substrate temperature of R.T～400 $^{\circ}C$, annealing temperature of 100～400 $^{\circ}C$, and sputtering gas pressure of 4${\times}$10$^{-3}$ Torr～4${\times}$10$^{-2}$ Torr. And the films were examined by X-ray diffraction analysis (XRD), scanning electron microscopy(SEM) and 4-point measurement system. The best electrical and structural properties was obtained by substrate temperature of ～200 $^{\circ}C$, target-substrate distance of ～14 cm and sputtering pressure of ～1${\times}$10$^{-2}$ Torr. Also at that condition the most excellent adhesion was observed.