• Title/Summary/Keyword: Monolayer films

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Dielectric Relaxation Phenomena of DMPC LB Thin Film (DMPC LB박막의 유전완화현상)

  • Choi, Youbg-Il;Song, Jin-Won;Cho, Su-Young;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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    • pp.822-825
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    • 2003
  • Maxwell displacement current (MDC) measurement has been employed to study the dielectric property of Langmuir-films. A method for determining the dielectric relaxation time $\tau$ of floating monolayers on water surface is presented. WC flowing across monolayers is analyzed using a rod-like molecular model. It is revealed that the dielectric relaxation time $\tau$ of monolayers in the isotropic polar orientational phase is determined using a liner relationship between the monolayer compression speed ${\alpha}$ and the molecular area Am. Compression speed ${\alpha}$ was about 30, 40, 50mm/min.

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A Study on the Light Response of p-PDA-AA (p-PDA-A.A의 광반응에 관한 연구)

  • Song, Jin-Won;Lee, Kyung-Sup;Choi, Young-Il;Kim, Hyung-Gon;Kim, Nam-Oh
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.05b
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    • pp.117-119
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    • 2000
  • Photoreactive multilayer films were prepared using long-chin alkyl diesters of p-phenylenediacrylic acid(p-PDA). In spite of the absence of hydrophilic groups in these molecules. they formed stable mono layers on the water surface when mixed with arachidic acid. Surface showed the presence of a condecsed phase and these monolayer could be transferred onto a substrate with Y-type deposition.

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Tribological properties of mono/multilayer LB molecular films (단층/다층 LB 분자막의 트라이볼로지 특성)

  • ;;G.K. Zhavnerko
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.211-214
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    • 2003
  • The tribological properties of amphiphilic monolayers and composite multilayer on silicon surface were investigated using micro-tribometer and Auger Electron Spectroscopy. Langmuir-Blodgett (LB) monolayers from behenic acid. 2.4-heneicosanedione(HD) and its copper complex((HD)$_2$Cu) were fabricated on silicon surface and the composite multilayer of 5-bilayer of (HD)$_2$Cu was fabricated on the surface of octadecyltrichlorsilane (OTS) self-assembled monolayer(SAM). We observed that LB monolayers and the composite multilayer exhibited a steady and excellent friction response when compared with the OTS SAM. These LB mono and multilayer also showed much higher wear-resistance than the OTS SAM.

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Electrochemical Characterization of Nanosized Electrode Arrays Prepared from Nanoporous Self-Assembled Monolayers

  • Choi, Shin-Jung;Park, Su-Moon
    • Bulletin of the Korean Chemical Society
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    • v.23 no.5
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    • pp.699-704
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    • 2002
  • We characterized nanoelectrode arrays prepared from self-assembled monolayers (SAMs) by adsorption from a solution containing thiolated $\beta$-cyclodextrin ($\beta$-CD) and n-alkanethiol on the gold electrode surface, using electrochemical methods. While the framework, the n-hexadecanethiol SAM, effectively blocked electron transfer between the electrode surface and solution-phase redox probe molecules, the $\beta$-CD cavities isolated in the forests of n-hexadecanethiol molecules were shown to act as an ultramicroelectrode array. The shapes of cyclic voltammograms of probe molecules were related to the number densities of $\beta$-CD molecules within the monolayer films. Probe molecules that have the correct combination of physical and chemical characteristics were shown to effectively penetrate the framework through the $\beta$-CD pores and exchange electrons with the electrode surface.

Photoluminescence Characteritics of Electrosprayed Eu(III) Doped Y2O3 Nanorods on a Si Substrate

  • Sin, Won-Gyu;Park, Mi-So;Son, Yeong-Gu
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.435-435
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    • 2014
  • Eu(III)-doped Y2O3 nanorods were deposited onto a Si substrate using electrostatic spray system. The photoluminescence imaging profiles were compared between the electrospray film and powder form. Using electrostatic spraying technique is very advantageous to generate a uniform monolayer film without much clustering of nanorods. Strong emission peaks were observed between 580 and 730 nm in response to an indirect excitation transition. Our results indicate that the electrospray technique could be very useful for generating thin films for displays and sensors.

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Investigations of Graphene Grown on Copper Substrates

  • Cho, Sangmo;Kang, Yura;Nam, Jungtae;Kim, Keun Soo;Hong, Suklyun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.188.2-188.2
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    • 2014
  • Chemical vapor deposition (CVD) method is usually used to grow high-quality large area graphene. In the CVD process, copper is an especially important catalytic-substrate due to the fact that graphene films grown on Cu foils are predominantly one monolayer thick. In this study, we has grown graphene on several types of copper substrates: Cu foils and copper single crystal surfaces such as Cu(100) and Cu(111) are chosen. To investigate the differences between graphene grown on foils and single crystals, we use Raman spectroscopy, X-ray diffraction and atomic force microscopy. Details of the experimental results will be presented.

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Antireflection Structures and Optical Recording Properties of Te-based Alloy Thin Films (Te계 합금 박막의 Antireflection 구조와 광기록 특성)

  • Lee, Hyun-Yong;Choi, Dae-Young;Lee, Young-Jong;Chung, Hong-Bae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1988.05a
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    • pp.74-77
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    • 1988
  • This paper reports the properties of antireflection structure and hole formation of Te-based systems. The optical-recording characteristics of metallic recording media are enhanced significantly by incorporating the metal(Al) layer into an antreflection trilayer structure. Due to the interface condition inherent in the design of the trilayer structure, reflectivity from holes is ranked low fraction (<10%). The hole formation is carried by $Ar^+$ Laser(488nm). For 20nsec pulse duration, hole opening power(threschold) of $(Te_{86}Se_{14})_{50}Bi_{50}$ trilayer is lower than that of monolayer that used in this experiment. Hole shapes of the whole sample were clean.

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Magnetic and Magneto-optical Properties of Ni/Pt Multilayers with Perpendicular Magnetic Anisotropy at Room Temperature

  • G. Srinivas;Shin, Sung-Chul
    • Journal of Magnetics
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    • v.2 no.4
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    • pp.138-142
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    • 1997
  • The magnetic and magneto-optical properties of Ni/Pt multilayers exhibiting square Kerr hysterisis loops at room temperature were studied. Squared polar Kerr hysterisis loops at room temperature in Ni/Pt multilayer thin films were obtained for the samples prepared by sequential dc magnetron sputter deposition of nickel and platinum with tNi=13-21$\AA$ and tPt=3.5-7.5$\AA$. The coercivity of these multilayers was in the range of 400-1100 Oe. The saturation magnetization was found to show an inverse dependence on nickel sublyaer thickness. About a monolayer of Ni at interface was observed to behave less magnetically than the interior Ni atoms. The polar Kerr rotation exhibited an increasing trend with decreasing wavelength in the spectral range of 7000-4000 $\AA$. The maximum of polar Kerr rotation was found to shift to higher wavelengths with increase in nickel sublayer thickness.

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Electrical properties of Organic TFT patterned by shadow-mask with all layer

  • Lee, Joo-Won;Kim, Jai-Kyeong;Jang, Jin;Ju, Byeong-Kwon
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.543-544
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    • 2006
  • Pentacene thin film transistors fabricated without photolithographic patterning were fabricated on the plastic substrates. Both the organic/inorganic thin films and metallic electrode were patterned by shifting the position of the shadow mask which accompanies the substrate throughout the deposition process. By using an optically transparent zirconium oxide ($ZrO_2$) as a gate insulator and octadecyltrimethoxysilane (OTMS) as an organic molecule for self-assembled monolayer (SAM) to increase the adhesion between the plastic substrate and gate insulator and the mobility with surface treatment, high-performance transistor with field effect mobility $.66\;cm^2$/V s and $I_{on}/I_{off}$>$10^5$ was formed on the plastic substrate. This technique will be applicable to all structure deposited at low temperature and suitable for an easy process for flexible display.

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