• 제목/요약/키워드: Spin glass

검색결과 259건 처리시간 0.022초

스핀코팅으로 제작된 Cu2O 필름의 광전기적 특성 (Optoelectronic Characteristics of Transparent Cu2O Films Spin-coated on Glass Substrates)

  • 곽기열;조경아;김상식
    • 전기학회논문지
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    • 제59권1호
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    • pp.123-126
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    • 2010
  • $Cu_2O$ nanoparticles-based films are fabricated by spin-coating on glass substrates and their optoelectronic characteristics are investigated in this study. The $Cu_2O$ films are nearly all-transparent as high as 98% in a wavelength range from 400 nm to 900 nm and three exciton peaks associated with the sublevels in the conduction band are observed at the wavelengths shorter than 400 nm in the absorption spectrum. Under the illumination of the 325 nm wavelength light, the photocurrent efficiency of the $Cu_2O$ film is $1.8\times10^5 {\mu}A/W$ at a voltage of 2.5 V in air.

공기중의 벤젠제거에 대한 산화티타늄 광촉매 반응특성 (Photocatalytic Reactivity of Titanium Dioxide in the Removal of Benzene from Air)

  • 박달근
    • 한국대기환경학회지
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    • 제16권4호
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    • pp.389-398
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    • 2000
  • Photocatalytic removal of benzene from air was examined using titanium dioxide photocatalyst films prepared on soda lime glass(50$\times$50$\times$2 mm) by spin coating and chemical vapor deposition. For the measurement of photocatalytic reactivity titanium dioxide coated glass was placed into a batch reactor and concentration of benzene in the reactor was set to abuot 100 ppm, and then illuminated with UV. It was found that catalytic reactivity of titanium dioxide films increased with the increase of titanium dioxide film thickness and then level off beyond a certain film thickness. UV absorption by the films showed the similar trend. The formation of stoichiometric amount of carbon dioxide was confirmed by measurement of carbon dioxide concentration in the reactor. In general spin coated films revealed better photocatalytic reactivity than chemically deposited one within the experimental ranges covered in this study. Morphology and crystal structure of prepared films were investigated by XRD and SEM and they showed significant difference between spin coated films and CVD films. Highest quantum efficiency of prepared titanium dioxide photocatalyst was close to 50%.

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CF$_4$ 플라즈마 처리로 불소를 첨가한 실록산 Spin-On-Glass 박막의 특성 (Properties of Spin-On-Glass Siloxane Thin Films Fluorine-doped by CF$_4$ Plasma)

  • 김현중;김기호
    • 한국표면공학회지
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    • 제34권3호
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    • pp.258-263
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    • 2001
  • Siloxane thin films were fabricated on a silicon wafer by spin-coating using a siloxane solution made by the sol-gel process. Fluorine was doped using$ CF_4$ plasma treatment. The film was then annealed in-situ state in the nitrogen atmosphere. In order to examine the influence of annealing and fluorine doping on the siloxane thin film, thermogravimetric-differential thermal analysis (TG-DTA), Fourier transform-infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) were used and the dielectric constant was determined by the high-frequency capacitance-voltage method. Stable siloxane films could be obtained by in-situ annealing in a nitrogen atmosphere after $CF_4$ plasma treatment, and the dielectric value of the film was $\varepsilon$ 2.5.

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단백질 칩 기판의 표면 스크래칭 효과 (Effects of Scratching on the Surface of Protein Chip Plates)

  • 현준원;황정일
    • 한국표면공학회지
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    • 제40권2호
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    • pp.98-102
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    • 2007
  • [ $NiCl_2$ ] and poly-L-lysine coated protein chip plates have been fabricated using a spin coating system. Water has been used as solvent and scratching effects on glass slides and ITO have been investigated. We also observed the surface properties of $NiCl_2$ and poly-L-lysine coated slides by using PSA(Particle size analyzer) and AFM(Atomic force microscope). The AFM results imply that the surface patterns created in the spin coating system determine the protein adsorption. Adsorption of histidine-tagged KRS proteins immobilized on glass slides and ITO was analyzed using a BAS image system. The results suggest that the scratching effect was increased ability of protein adsorption.

Ti-naphthenate의 코팅-열분해에 의한$TiO_2$ 박막의 제조 (Preparation of $TiO_2$ thin films by coating-pyrolysis process of Ti-naphthenate)

  • 김진영;김승원;장우석;김현태;최상원
    • 한국결정성장학회지
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    • 제12권1호
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    • pp.7-10
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    • 2002
  • $TiO_2$ 박막을 금속유기화합물인 Titanium-naphthenate의 코팅-열분해법으로 제조하였다. 출발물질은 Ti-naphthenate를 toluene에 희석한 용액을 사용하였으며 기판은 slide glass를 사용하였다 Titanium-naphthenate 용액을 spin-coating법으로 기판에 코팅하고 $450^{\circ}C$에서 열터리하여 $TiO_2$ 박막을 제조하였다 제조한 박막의 특성을 UV/Vis, XRD 및 SEM 등으로 박막의 투과율, 굴절률, 결정상 및 표면 형상을 분석하였다. Slide glass 위에 제조한 TiO$_2$ 박막은 투과율은 70~90%이며 420nm에서의 굴절율은 2.7이었다. $TiO_2$박막은 anatase상을 나타내었고 실타래 형상의 주름을 가진 표면을 나타내었다

Effect of Modified Starches on Caking Inhibition in Ramen Soup

  • Wee, Hye-Won;Choi, Young-Jin;Chung, Myong-Soo
    • Food Science and Biotechnology
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    • 제16권4호
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    • pp.646-649
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    • 2007
  • The effect of the addition of 2 kinds of chemically modified starches (the anti-caking agents; tapioca starch and com starch) on caking of ramen soup was observed using a low-resolution proton-pulsed nuclear magnetic resonance (NMR) technique. After storing ramen soup samples with diverse compositions of modified starch at 20-40% relative humidity for 4 weeks, changes in the spin-spin relaxation time constant ($T_2$) were measured as a function of temperature. $T_2-Temperature$ curves for ramen soup containing modified starches showed that the caking initiation temperature (glass transition temperature) was increased by $5^{\circ}C$ following the addition of only 0.5% modified cornstarch. The results indicate that the modified com starch used in this study would be an effective anti-caking agent for ramen soup, thus prolonging the shelf life of the product.

금속나노입자-유전체 이층 구조 구현을 위한 반투명 Cu 나노입자층 형성에 관한 연구 (Study on Formation of Semitransparent Cu Nanoparticle Layers for Realizing Metal Nanoparticle-Dielectric Bilayer Structures)

  • 윤혜련;조윤이;윤회진;이승윤
    • 한국전기전자재료학회논문지
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    • 제33권6호
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    • pp.460-464
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    • 2020
  • This study reports the fabrication and application of semitransparent Cu nanoparticle layers. Spin coating and subsequent drying of a Cu colloid solution were performed to deposit Cu nanoparticle layers onto Si and glass substrates. As the spin speed of the spin coating increases, the density of the nanoparticles on the substrate decreases, and the agglomeration of nanoparticles is suppressed. This microstructural variation affects the optical properties of the nanoparticle layers. The transmittance and reflectance of the Cu nanoparticle layers increase with increasing spin speed, which results from the trade-off between the exposed substrate area and surface coverage of the Cu nanoparticles. Since the glass substrates coated with Cu nanoparticle layers are semitransparent and colored, it is anticipated that the application of a Cu nanoparticle-dielectric bilayer structure to transparent solar cells will improve the cell efficiency as well as aesthetic appearance.

Ordering of manganese spins in photoconducting $Zn_{1-x}Mn_xTe$

  • Kajitani, T.;Kamiya, T.;Sato, K.;Shamoto, S.;Ono, Y.;Sato, T.;Oka, Y.
    • 한국결정성장학회:학술대회논문집
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    • 한국결정성장학회 1998년도 PROCEEDINGS OF THE 14TH KACG TECHNICAL MEETING AND THE 5TH KOREA-JAPAN EMGS (ELECTRONIC MATERIALS GROWTH SYMPOSIUM)
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    • pp.39-43
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    • 1998
  • Single crystals of{{{{ { Zn}_{ 1-x} {Mn }_{x }{Te} }}}} with x=0.3-0.6 were prepared by the standard Bridgeman method. Diffuse neutron diffraction intensities due to the short range magnetic ordering is found in the vicinities of 1 1/2 0 reciprocal point and its equivalent point, indicating that the magnetic correlation of the clusters is the type III antiferromangetic one do the F-type Bravais class crystals, being identical with that of {{{{{ Cd}_{ 1-x} {Mn }_{x }Te }}}}. Neutron inelastic scattering measure-ment has been performed for {{{{{ Zn}_{ 0.6} { Mn}_{ 0.4}Te }}}} sample using the cold neutron spectrometer. AGNES. High resolution measurement with the energy resolution of {{{{ TRIANGLE E= +- .01meV}}}} was carried out in the temperature range from 10K to the ambient. Critical scattering, closely related with the spin glass transition, has been observed for the first time in this semimagnetic semi-conductor. The critical scattering is observed at temperatures in the vicinity of the spin glass transition temperature, 17K. The scattering is observed as a kind of quasielastic scattering in the reciprocal range where the elastic magnetic diffuse scattering has been observed, e.g., 11/20 reciprocal point, indicating the spin fluctuation has dynamic components in this material. Photoconductivity has been discovered below 150K in {{{{{ Zn}_{ 0.4} {Mn }_{0.6 } Te}}}}. The electric AC conductivity has been increased dramatically under the laser light with the wave lengths of {{{{ lambda =6328,5145 and4880 }}}}$\AA$ ,respectively. After the light was darkened, the conductivity was reduced to the original level after about 2000 seconds at 50K, being above the spin glass transition temperature. This phenomenon is the typical persistent photoconductivity; PPC which was similarly found in {{{{ { Zn}_{ 1-x} { Mn}_{x} Te}}}}.

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습식공정 기반 ITO 기판 위 산화아연 나노로드 모폴로지 제어 (Morphology Control of ZnO Nanorods on ITO Substrates in Solution Processes)

  • 신경식;이삼동;정순욱;이상우;김상우
    • 한국전기전자재료학회논문지
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    • 제22권11호
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    • pp.987-991
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    • 2009
  • We report growth of vertically well-aligned zinc oxide (ZnO) nanorods on indium-tin oxide (ITO)/glass substrates using a simple aqueous solution method at low temperature via control of the ZnO seed layer morphology. ZnO nanoparticles acting as seeds are pre-coated on ITO-coated glass substrates. by spin coating to control distribution and density of the ZnO seed nanoparticles. ZnO nanorods were synthesized on the seed-coated substrates in a dipping process into a main growth solution. It was found that the alignment of ZnO nanorods can be effectively manipulated by the spin-coating speed of the seed layer. A grazing incidence X-ray diffraction pattern shows that the ZnO seed layer prepared using the higher spin-coating speed is of uniform seed distribution and a flat surface, resulting in the vertical growth of ZnO nanorods aligned toward the [0001] direction in the main growth process.