• Title/Summary/Keyword: Electronic spectra

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Studies on Effective Utilization of X -ray Energy Using Intensifying Screens (증감지의 X-선 에너지 유효 이용에 관한 연구)

  • Kim, Y.K.;Lee, K.S.
    • Proceedings of the KIEE Conference
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    • 1998.11c
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    • pp.825-828
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    • 1998
  • The X-ray spectra dependence for intensifying screens of medical radiography was investigated through analysis of the absorbed coefficiency($\mu$), absorbed efficiency(${\eta}_{\alpha}$) and absorbed ratio(R). It was found that the absorbed coefficiency was increased in the order of $CaWO_4$$CaWO_4$ screen showed the highest value.

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A study on the crystallization processing of photosensitive glass by FT-IR and FT-Raman spectroscopy (FT-IR과 FT-Raman 분광계를 이용한 광민감유리의 결정화 과정에 관한 연구)

  • 이명원;강원호
    • Electrical & Electronic Materials
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    • v.10 no.3
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    • pp.284-288
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    • 1997
  • FT-IR and FT-Raman spectra were measured for 15Li$_{2}$O.3Al$_{2}$O$_{3}$.78SiO$_{2}$. 4K$_{2}$O glass system after UV irradiations. Optimum UV irradiation time of Li$_{2}$O.SiO$_{2}$ crystalline phase was 60 seconds and crystalline phase of Li$_{2}$O.SiO$_{2}$ was leached out on 5% HF. 977 cm$^{1}$ band of FT-Raman spectra can be attributed to two-non bridging oxygen in unit cell for 1 hour and optimum crystallization was confirmed for 3 hrs, 630.deg. C.

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ZnO Crystals with Belt and Comb Shapes Synthesized by Oxidation of ZnS in Air Atmosphere (공기 중 대기압 분위기에서 ZnS의 산화에 의해 생성된 벨트형상과 빗 형상의 ZnO 결정)

  • Lee, Geun-Hyoung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.11
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    • pp.920-924
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    • 2011
  • ZnO crystals with belt and comb shapes were synthesized without any catalysts through a simple thermal oxidation of ZnS powder in alumina crucible under air atmosphere. X-ray diffraction (XRD) pattern revealed that the ZnO crystals had wurtzite structure of hexagonal phase. Energy dispersive x-ray (EDX) spectra showed that the ZnO was of high purity. In the cathodoluminescece spectra obtained for the ZnO crystals with belt and comb shapes, a strong ultraviolet emission centered at 380nm was observed, which indicates the ZnO crystal has high crystalline quality.

Characteristics of ZnO Films Deposited on Poly 3C-SiC Buffer Layer by Sol-Gel Method

  • Phan, Duy-Thach;Chung, Gwiy-Sang
    • Transactions on Electrical and Electronic Materials
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    • v.12 no.3
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    • pp.102-105
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    • 2011
  • This work describes the characteristics of zinc oxide (ZnO) thin films formed on a polycrystalline (poly) 3C-SiC buffer layer using a sol-gel process. The deposited ZnO films were characterized using X-ray diffraction, scanning electron microscopy, and photoluminescence (PL) spectra. ZnO thin films grown on the poly 3C-SiC buffer layer had a nanoparticle structure and porous film. The effects of post-annealing on ZnO film were also studied. The PL spectra at room temperature confirmed the crystal quality and optical properties of ZnO thin films formed on the 3C-SiC buffer layer were improved due to close lattice mismatch in the ZnO/3C-SiC interface.

Effect of Double Schottky Barrier in Gallium-Zinc-Oxide Thin Film

  • Oh, Teresa
    • Transactions on Electrical and Electronic Materials
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    • v.18 no.6
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    • pp.323-329
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    • 2017
  • This reports the electrical behavior, bonding structure and Schottky contact of gallium-zinc-oxide (GZO) thin film annealed at $100{\sim}400^{\circ}C$. The mobility of GZO with high density of PL spectra and crystal structure was also increased because of the structural matching between GZO and Si substrate of a crystal structure. However, the GZO annealed at $200^{\circ}C$ with an amorphous structure had the highest mobility as a result of a band to band tunneling effect. The mobility of GZO treated at low annealing temperatures under $200^{\circ}C$ increased at the GZO with an amorphous structure, but that at high temperatures over $200^{\circ}C$ also increased when it was the GZO of a crystal structure. The mobility of GZO with a Schottky barrier (SB) was mostly increased because of the effect of surface currents as well as the additional internal potential difference.

Optical Absorption Spectra of Mixed Merocyanine Dye LB films (혼합 매로시아닌 LB막의 광흡수 스펙트라)

  • 신훈규;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.05a
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    • pp.35-42
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    • 1996
  • In this Paper, optical absorption were performed on LB films of binary mixtures of three kinds of merocranine dyes DO, DS, and 6Me-BS, where DS and 6Me-DS form J-like aggregates but not DO in single component films. The observed optical absorption spectra of mixed films were markedly defendent on the combination of dyes. [6Me-DS]$\sub$1-x/[DOl]$\sub$x/ LB films show a sharp red shifted J-like band peak in the whole concentration range. We found the formation of f aggregates in a mixed merocyanine dyes containing a non J-aggregate forming dye DO, in a single component case. Farther investigations on the present and other mixed-dye films will be needed to clarify these points.

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Structure Control of Merocyanine LB Films by Optical Absorption Spectra (광 흡수 Sepectra 에 의한 메로시아닌 LB막의 구조제어)

  • 신훈규;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.11a
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    • pp.401-404
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    • 1996
  • Optical absorption were performed on LB films of binary mixtures of three kinds of merocyanine dyes [DO], [DS], and [6Me-DS], where [DS] and [6Me-DS] from J-like aggregates but not [DO] in single component films. The observed optical absorption spectra of mixed films were markedly dependent on the combination of dyes. [DS]$_{1-x}$ [DO]$_{x}$ LB films show a sharp red shift J-like band peak in the while concentration range. We found the formation of J-aggregates in a mixed merocyanine dyes containing a non J-aggregate forming dye [DO], in a single component case. Further investigations on the present and other mixed dye films will be needed to clarify these points.ts.

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Photodissociation Dynamics of Cyanamide at 212 nm

  • Kwon, Chan-Ho;Lee, Ji-Hye;Kim, Hong-Lae
    • Bulletin of the Korean Chemical Society
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    • v.28 no.9
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    • pp.1485-1488
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    • 2007
  • Photodissociation dynamics of cyanamide (NH2CN) at 212 nm has been investigated by measuring rotationally resolved laser induced fluorescence spectra of CN fragments exclusively produced in the ground electronic state. From the spectra, rotational population distributions of CN as well as translational energy releases in the products were obtained. The measured average rotational energies of CN were 12.4 ± 0.5 and 11.6 ± 0.5 kJ/ mol for v'' = 0 and v'' = 1, respectively and the center of mass average translational energy release among products was 41.8 ± 6.4 kJ/mol. The observed energy partitioning was well represented by statistical prior calculations, from which it was suggested that the dissociation takes place on the ground electronic surface after rapid internal conversion.

Preparation and Characterization of Nickel(Ⅱ) and Copper(Ⅱ) Tetaaza Macrocyclic Complexes with Isonicotinate Ligands

  • Choi, Ki-Young;Kim, Moon-Jip;Kim, Dae-Sue;Kim, Yong-Son;Kim, Jae-Hyun;Ryu, Hai-Il;Lim, Youn-Mook;Kang, Seung-Gu;Shin, Ueon-Sang;Lee, Kyu-Chul;Hong, Choon-Pyo
    • Bulletin of the Korean Chemical Society
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    • v.23 no.8
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    • pp.1062-1066
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    • 2002
  • The complexes [Ni(L)(INT)2]${\cdot}$5H2O (1) and [Cu(L)(H2O)](Cl)(INT)${\cdot}$3H2O (2) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.18 ,07.12 ]docosane, INT = isonicotinate) have been prepared and characterized by X-ray crystallography, electronic absorption, and cyclic voltammetry. The crystal structure of 1 reveals an axially elongated octahedral geometry with two axial isonicotinate ligands. The electronic spectra, magnetic moment, and redox potentials of 1 also show a high-spin octahedral geometry. However, 2 shows that the coordination environment around the copper atom is a distorted square-pyramid with an axial water molecule. The spectra and electrochemical behaviors of 2 are also discussed.

Simulation of Material Properties of Amorphous Carbon Nitride with Non-uniform Nitrogen Distribution

  • Lu, Y.F.;He, Z.F.
    • Transactions on Electrical and Electronic Materials
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    • v.2 no.3
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    • pp.1-6
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    • 2001
  • A simulation method is proposed to study the amorphous structure of carbon nitride. The material properties of a non-uniform nitrogen distribution in an amorphous CN matrix can be studied. The cohesive energy of a group of randomly generated atoms can be minimized to find the relative positions of atoms. From the calculated configuration of atoms, many properties of amorphous carbon nitride can be calculated such as bulk modulus, P-V curve, sp$^3$/sp$^2$ ratio of carbon, and vibrational spectra. The calculation shows that the cohesive energy of non-uniform nitrogen distribution is lower than that of a uniform distribution. This may suggest that the regular structure of carbon nitride can at most be metastable. It is not easy to incorporate nitrogen atoms into a carbon matrix.

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