• Title/Summary/Keyword: Low-spin

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Factors Affecting the Magnitude of the Metal-Insulator Transition Temperature in AMo4O6 (A=K, Sn)

  • Jung, Dong-Woon;Choi, Kwang-Sik;Kim, Sung-Jin
    • Bulletin of the Korean Chemical Society
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    • v.25 no.7
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    • pp.959-964
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    • 2004
  • A low-dimensional metal frequently exhibits a metal-insulator transition through a charge-density-wave (CDW) or a spin-density-wave (SDW) which accompany it's structural changes. The transition temperature is thought to be determined by the amount of energy produced during the transition process and the softness of the original structure. $AMo_4O_6$ (A=K, Sn) are known to be quasi-one dimensional metals which exhibit metalinsulator transitions. The difference of the transition temperatures between $KMo_4O_6$ and $SnMo_4O_6$ (A=K, Sn) is examined by investigating their electronic and structural properties. Fermi surface nesting area and the lattice softness are the governing factors to determine the metal-insulator transition temperature in $AMo_4O_6$ compounds.

Condensation and Baking Effects of Polymer Gate Insulator for Organic Thin Film Transistor

  • Kang, S.I.;Park, J.H.;Jang, S.P.;Choi, Jong-S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.1046-1048
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    • 2004
  • Performances of organic thin film transistors (OTFTs) can be detrimentally affected by the state of the gate dielectric. Because of the bad stability of polymers, OTFTs with polymer gate dielectrics often provide abnormal characteristics. In this study, we report the condensation effect of the polymer gate dielectric layer. For the observations of the effect of the condensation, the spin-coated polymer layers with various deposition conditions were fabricated and left under low vacuum condition for several days. It is observed that the thickness of polymer layer and the electrical characteristic of OTFTs vary with the condensation time.

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The Effects of Sintering Temperature of Organic Ag Complex on the Photoluminescence Characteristics of MEH-PPV (유기 은(Ag) 화합물의 소결 온도가 MEH-PPV의 PL특성에 미치는 영향)

  • Kang, Min-Ki;Moon, Dae-Gyu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.328-329
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    • 2009
  • This paper presents the effect of organic Ag complex sintering temperature on the MEH-PPV photoluminescence (PL) properties. MEH-PPV and organic Ag complex was coated on the glass substrate by spin coating method. The coated Ag complex was sintered in an air atmosphere. The sintering temperature was varied from 100 to $200^{\circ}C$ and sintering time was 5 min. The Ag film sintered at temperature higher than $120^{\circ}C$ shows very low sheet resistance less than $0.5\;{\Omega}{/\square}$. The coated MEH-PPV measure photoluminescence (PL) intensity at 580 nm. The PL peak was shifted to the higher wavelength with increasing the sintering temperature.

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Effect of Solvent on the Surface of Protein Chip Plate (단백질 칩 기판의 표면에 미치는 용매 효과)

  • 현준원;윤미영;안상민;노승정;허영덕;박헌용;송예신;피재호;김경례
    • Journal of the Korean institute of surface engineering
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    • v.37 no.2
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    • pp.76-79
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    • 2004
  • Nickel chloride coated protein chip plate was developed by using a spin coating method. The ability of histidine tagged protein adsorption was investigated at various solvents. The surface of plate has a large aggregated nickel complex with high density in water. However, the surface of plate has a very small size of aggregated nickel complex with low density in isopropanol. The ability of protein adsorption decreased as increasing the size of alkyl chain in various alcohol solvents. The mechanism on the ability of protein adsorption at the plate surface is discussed.

Effect of Prefiring Time on Epitaxy and crystallinity of Pb(Zr, Ti)O$_3$ Thin Films in Low Temperature Pyrolysis (저온도포열분해에 의해 제조된 Pb(Zr, Ti)O$_3$ 박막의 에피탁시와 결정화도에 미치는 전열처리 시간의 영향)

  • 황규석;이형민;김병훈
    • Journal of the Korean Ceramic Society
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    • v.35 no.9
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    • pp.969-973
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    • 1998
  • Pb(Zr, Ti)O3 (PZT) (Zr:Ti= 52: 48) thin films were prepared on MgO(100) substrates by dipping-py-rolysis process using metal naphthenates as starting materials. Thin films were fabricated by spin coating technique and the precursor films were prefired at 20$0^{\circ}C$ in air for 0.5, 1, 2, 3, and 24 h followed by final heat treatment at 75$0^{\circ}C$ for 30min. Film prefired for 24 h lost orientational properties and pole figure analysis showed the lost of the epitaxial relationship between the films and substrate while highly a/c-axis oriented thin films were obtained for the samples prefired for 1, 2, and 3h.

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A Study of Mastless Pattern Fabrication using Stereolithography (광조형을 이용한 마스크리스 패턴형성에 관한 연구)

  • 정영대;조인호;손재혁;임용관;정해도
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.503-507
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    • 2002
  • Mask manufacturing is a high COC and COO process in developing of semiconductor devices, because of the mass production tool with high resolution. Direct writing has been thought to be one of the patterning method to cope with development or small-lot production of the device. This study focused on the development of the direct, mastless patterning process using stereolithography tool for the easy and convenient application to micro and miso scale products. Experiments are utilized by three dimensional CAD/CAM as a mask and photo-curable resin as a photo-resist in a conventional stereo-lithography apparatus. Results show that the resolution of the pattern was achieved about 300 micron because of complexity of SLA apparatus settings, inspite of 100 micro of inherent resolution. This paper concludes that photo resist and laser spot diameter should be adjusted to get finer patterns and the proposed method is significantly feasible to mastless and low cost patterning with micro and miso scale.

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Investigation of Head-Disk Interactions at Ultra-low Flying HDI

  • Cho, Unchung
    • KSTLE International Journal
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    • v.3 no.2
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    • pp.114-118
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    • 2002
  • In this work, head-disk interactions are studied when flying height becomes lower than laser bump height on the landing zone of a disk. With the reduction of the spinning speed in a spin stand, the flying height is decreased under the height of laser bumps. Conventional and padded pico sliders sweep between landing Bone and data zone and, then, the dynamic behavior of the pico sliders and head-disk impacts are investigated using AE and stiction/friction signals. After 200n cycle-sweep tests, bearing analysis and AFM analysis indicate that there are some signs of wear and plastic deformation in the landing zone of a disk, although AE and stiction/friction signals are not significantly changed during the sweep tests. The experimental results of this paper suggest that in CSS tests at component level, more rigorous examination methods of wear and plastic deformation might be necessary as flying height becomes getting lower.

Metal induced crystallization of amorphous silicon using metal solution

  • Yoon, Soo-Young;Oh, Jae-Young;Kim, Chae-Ok;Jang, Jin
    • Journal of the Korean Vacuum Society
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    • v.7 no.s1
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    • pp.123-133
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    • 1998
  • Amorphous silicon (a-Si) was crystallized by metal induced crystallization using metal solution. The a-Si films spin coated with a 50,000 ppm Ni solution were crystallized at as low as $500^{\circ}C$. Needlelike morphology, developed as a result of the migration of $NiSi_2$, precipitates, appears in the MIC poly-Si. The growth of the needlelike crystallites proceeds to a direction parallel to (111). The crystallization temperature can be lowered to $450^{\circ}C$ by Au addition. The enhancement of crystallization results from the decrease of interfacial energy at the NiSi2/Si interface by Au addition.

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Estimation of Insolation over the Oceans around Korean Peninsula Using Satellite Data

  • Park, Kyung-Won;Kim, Young-seup;Sang, Chung-Hyo
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.227-230
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    • 1999
  • Surface solar radiation over the sea is estimated using Visible and Infrared Spin Scan Radiometer data onbord Geostationary Meteorological Satellite(GMS) 5 for January, 1997 to December 1997 in clear and cloudy conditions. The hourly insolation is estimated with a spatial resolution of 5$\times$ 5 km grid. The island pyranometer belonging to the Japan Meteorological Agency is used for validation of the estimated insolation. It is shown that the estimated hourly insolation has RMSE(root mean square) error of 104 W/$m^2$. The variability of the hourly solar radiation was investigated on 3 areas over seas around Korean Peninsula. The solar radiation of East Sea is similar to Yellow Sea. The maximum value of solar radiation is on June of year. The maximum value in south sea is on August because weather is poor by low pressure and front in June

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Study on the characteristics of transpatent electronic Ag (20%) ink by sintering conditions (투명전자잉크 Ag(20%)의 소성조건에 따른 특성 연구)

  • Kang, Min-Ki;Moon, Dae-Gyu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.04a
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    • pp.78-79
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    • 2009
  • We have investigated low temperature sintering characteristics of organic Ag complex. Organic Ag complex was coated on the glass substrate by spin coating method. The coated Ag complex was sintered in an air atmosphere. The sintering temperature was varied from 30 to $80^{\circ}C$ and sintering time was varied from 1 to 228 hour. The sheet resistance was abruptly changed at $80^{\circ}C$-6h, $65^{\circ}C$-24h, $30^{\circ}C$-228 hour and the thickness of the coated film was significantly decreased. The sheet resistance of Ag films were about $0.53\;{\Omega}/{\square}$ at the $80^{\circ}C$ - 12hour.

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