• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.540-540
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• 2013

In this studying, we investigated the basic properties of N-doped plasma polymer. The N-doped ethylcyclohexane plasma polymer thin films were deposited by radio frequency (13.56 MHz) plasma-enhanced chemical vapor deposition method. Ethylcyclohexenewas used as organic precursor (carbon source) with hydrogen gas as the precursor bubbler gas. Additionally, ammonia gas [NH3] was used as nitrogen dopant. The as-grown polymerized thin films were analyzed using ellipsometry, Fourier-transform infrared [FT-IR] spectroscopy, Raman spectroscopy, FE-SEM, and water contact angle measurement. The ellipsometry results showed the refractive index change of the N-doped ethylcyclohexene plasma polymer film. The FT-IR spectrashowed that the N-doped ethylcyclohexene plasma polymer films were completely fragmented and polymerized from ethylcyclohexane.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.370-376
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• 1998

The powder preparation of Zinc-Silicate phosphors compound was studied by hydrothermal reaction starting from the precursor which prepared by spray pyrolysis method. This process protect including of impuritied from crushing process and Mineralizing in hydrothermal reactions. Using spray pyrolysis precursor, ${\alpha}-Zn_2SiO_4$ powder was prepared by the hydrothermal reaction under $250^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.35 no.11
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• pp.3299-3302
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• 2014

The In2S3 thin films of tetragonal structure and In2O3 films of cubic structure were synthesized by a spin coating method from the organometallic compound precursor triethylammonium indium thioacetate ($[(Et)_3NH]^+[In(SCOCH_3)_4]^-$; TEA-InTAA). In order to determine the electron mobility of the spin-coated TEA-InTAA films, thin film transistors (TFTs) with an inverted structure using a gate dielectric of thermal oxide ($SiO_2$) was fabricated. These devices exhibited n-channel TFT characteristics with a field-effect electron mobility of $10.1cm^2V^{-1}s^{-1}$ at a curing temperature of $500^{\circ}C$, indicating that the semiconducting thin film material is applicable for use in low-cost, solution-processed printable electronics.

• Korean Journal of Crystallography
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• v.12 no.2
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• pp.76-80
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• 2001

We have studied the effect of sintering conditions on the long-range order parameter of the 1 : 2 cation ordering in Ba(Mg/sub 1/3/Nb/sub 2/3/)O₃microwave dielectrics prepared through a columbite precursor method. It is found that the order parameter depends strongly on the sintering conditions. As the heat-treatment time increases at 1350℃, the long-range order parameter decreases. When sintered at 1500℃ for 4 hours, BMN shows a high long-range order parameter of 0.94.

• Fibers and Polymers
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• v.2 no.4
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• pp.178-183
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• 2001

A pitch precursor for a general purpose carbon fiber was prepared by condensation of pyrolized fuel oil (petroleum residual oil) with bromine under nitrogen blowing. such a condensation raised the softening point of the pitch from 4$0^{\circ}C$ to $265^{\circ}$ with a yield of 43%. The pitch precurosr showed an enhanced aromaticity and enlarged molecular size, which led to a reduction in molecular mobility and optical isotropy. The precursor was spun into fibers of $20\mu\textrm{m}$ diameter at a take-up speed of 700m/min. The fiber was stepwise stabilized in air and carbonized in Ar gas to obtain an isotropic carbon fiber. The carbon fiber exhibited tensile strengths of 500-800 ㎫though the fiber was formed via a crude method. The electric conductivity of the carbon fiber was relatively high, 2.2$\times$$10^2$S/cm, sufficient to be used as electrode materials.

• Fashion & Textile Research Journal
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• v.3 no.1
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• pp.42-47
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• 2001

The hardening system of polyurethanes has usually caused by air pollution. bad working condition and fire hazard according to using orgarnic solvents. Therefore there have been researched on emulsion, water soluble and colloid-dispersion based water soluble instead of using organic solvents recently. This study synthesized polyurethane dispersing particle by means of mixing precursor and neutralized emulsion method. In the first step, polyurethane was preparated from isophorone diisocyanate and poly (ethylene-adipate) glycol, and got precursor by introducing dimethyl propionic acid as a hydrophilic group. Synthesized polyurethane was bonded to the surface of fiber and crosslinked as a anti-static agent, and then looked for the change of color and softening property.

• Journal of Mechanical Science and Technology
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• v.15 no.12
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• pp.1691-1698
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• 2001

In recent years, significant progress has been made in modeling turbulence behavior in plasma and its effect on transport. It has also been made in diagnostics for turbulence measurement; however, there is still a large gap between theoretical model and experimental measurements. Visualization of turbulence can improve the connection to theory and validation of the theoretical model. One method to visualize the flow structures in plasma is a laser Schlieren imaging technique. We have recently applied this technique and investigated the characteristics of a highly underexpanded pulsed plasma jet originating from an electrothermal capillary source. Measurements include temporally resolved laser Schlieren imaging of a precursor blast wave. Analysis on the trajectory of the precursor blast wave shows that it does not follow the scaling expected for a strong shock resulting from the instantaneous deposition of energy at a point. However, the shock velocity does scale as the square root of the deposited energy, in accordance with the point deposition approximation.

• Progress in Superconductivity
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• v.1 no.1
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• pp.56-60
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• 1999

Ultra fine MgO particles added BSCCO tapes were fabricated by tape casting using Doctor Blade Method and enclosed by silver foil for different starting compositions (that is, 2223 major, 2212 major). In order to obtain optimum microstructure, thermomechanical treatment was done. Microstructure and phase were analyzed by XRD, SEM and DTA. The critical current density was measured under magnetic field at 77K. The tapes fabricated from the precursor powder with BSCCO-2223 phase (>90%) result in a microstructure with a larger grain size and higher transport critical current density value under magnetic field at given thermomechanical treatment conditions.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1219-1221
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• 1997

Poly(1,4-phenylene(1-methoxyenthylene)), organic water soluble PPV precursor was synthesized for polymer electroluminescence(EL) device. To control the molecular array, deposition method of emitter was Langmuir-Blodgett(LB). PPV precursor layer was treated thermally to conversion of PPV. Optical, electrical and EL properties of PPV LB thin film was estimated. Homogeneous light emission of greenish-yellow in PPV LB thin film can be easily confirmed under normal lighting even at low driving voltage. Polymer EL device using PPV LB thin film as emitter materials had a possibility to apply to next generation display device.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.8
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• pp.663-668
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• 2003

CdTe quantum dots(QDs) were synthesized in aqueous solution by colloidal method. The synthesized CdTe QDs were identified to be cubic-structured ones by x-ray diffraction(XRD). The photoluminescence(PL) was performed for CdTe QDs prepared as a function of Te precursor concentration, condensation time and aging time. The PL intensity is strongly dependent on Te precursor concentration, indicating that the ratio of Te to Cd ions affects the particle size and size distribution of the CdTe QDs. Our PL study reveals that the intensity of PL peaks strengthens as the condensation time elongates, implying that annealing by thermal energy transferred during condensation would eliminate defects which act as killing centers in CdTe particles. Our photocurrent study suggests that the CdTe QDs materials are one of the prospective materials for optoelectronics including photodetectors.