• 제목/요약/키워드: Electronic transition

검색결과 978건 처리시간 0.027초

$a-In_{2}Se_{3}$ 단결정의 전기전도도 특성 연구 (Electrical Conductivity Properties of the $a-In_{2}Se_{3}$ Single Crystal)

  • 김형곤;김남오;이우선
    • 한국전기전자재료학회논문지
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    • 제14권8호
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    • pp.629-633
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    • 2001
  • Electrical properties of the $\alpha$-In$_2$Se$_3$ single crystals grown by use of the Bridgman technique were examined in the transition temperature range between $\alpha$-phase and $\beta$-phase. $\alpha$-In$_2$Se$_3$ single crystal has ' the rhombohedral structure and lattice constants are a=4.025 $\AA$, c=28.771 $\AA$ in c-axis. The transition temperatures of the stoichiometric $\alpha$-In$_2$Se$_3$ single crystal is 198.8$^{\circ}C$ according to the specimens. The temperature of $\alpha$longrightarrow$\beta$ phase transition decreased but the temperature of $\beta$longrightarrow$\alpha$ phase transition increased as the number of heating-cooling cycle increased.

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에폭시 경화물 DSC에 의한 유리전이 온도 측정의 분석조건 의존성 (The Effect of DSC Analysis Condition on the Glass Transition Temperature of curred Epoxy This paper studies on the effect of DSC(Differential Scanning Calorimeter) analysis condition on the glass transition temperature of silica filled epoxy network polymer used for ultra-high voltage apparatus. The effects of temperature scanning rate specimen size and gas flow rate on measured glass transition temperature have been studied in order to select optimum thermal analysis condition.)

  • 오무원;권혁삼
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1994년도 춘계학술대회 논문집
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    • pp.30-33
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    • 1994
  • This paper studies on the effect of DSC(Differential Scanning Calorimeter) analysis condition on the glass transition temperature of silica filled epoxy network polymer used for ultra-high voltage apparatus. The effects of temperature scanning rate specimen size and gas flow rate on measured glass transition temperature have been studied in order to select optimum thermal analysis condition.

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천이 수정을 통한 고 성능 테스트 데이터 압축 기법 (A New High Performance Test-data Compression Scheme Using Transition Modification)

  • 박재석;양명훈;김용준;박영규;윤현준;강성호
    • 대한전자공학회논문지SD
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    • 제45권9호
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    • pp.57-64
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    • 2008
  • 본 논문은 높은 압축 성능을 가진 테스트 데이터 압축 기법을 제안한다. 제안하는 기법은 돈 케어 리맵핑을 이용한 천이 추가 단계와 천이 이전 단계로 구성된다. 실험 결과는 새로운 기법이 가장 높은 성능의 기법들 중 하나인 RL-huffman보다 높은 압축률을 제공하고 더 작은 하드웨어 면적을 필요로 함을 보여준다. 따라서 이 기법은 테스트 데이터 압축을 위한 실제적인 해법으로 널리 쓰일 수 있다.

칼코게나이드 박막의 전기적 펄스에 의한 상변화 연구 (The phase transition with electric field in chalcogenide thin films)

  • 양성준;신경;이재민;정홍배
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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    • pp.115-118
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    • 2004
  • The phase transition between amorphous and crystalline states in chalcogenide semiconductor films can controlled by electric pulses or pulsed laser beam; hence some chalcogenide semoconductor films can be applied to electrically write/erase nonvolatile memory devices, where the low conductive amorphous state and the high conductive crystalline stale are assigned to binary states. AST(AsSbTe) used to phase change material by applying electical pulses. Thickness of AST chalcogenide thin film have about 100nm. Electrodes are made of ITO and Al. $T_c$(Crystallization temperature) of AST system is lower than that of the GST(GeSbTe) system, so that the current pulse width of crystallization process can be decreased.

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Vapor Deposition Techniques for Synthesis of Two-Dimensional Transition Metal Dichalcogenides

  • Song, Jeong-Gyu;Park, Kyunam;Park, Jusang;Kim, Hyungjun
    • Applied Microscopy
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    • 제45권3호
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    • pp.119-125
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    • 2015
  • Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have attracted significant attention due to their unique and exotic properties attributed to their low dimensionality. In particular, semiconducting 2D TMDCs such as $MoS_2$, $WS_2$, $MoSe_2$, and $WSe_2$ have been demonstrated to be feasible for various advanced electronic and optical applications. In these regards, process to synthesize high quality 2D TMDCs layers with high reliability, wafer-scale uniformity, controllable layer number and excellent electronic properties is essential in order to use 2D TMDCs in practical applications. Vapor deposition techniques, such as physical vapor deposition, chemical vapor deposition and atomic layer deposition, could be promising processes to produce high quality 2D TMDCs due to high purity, thickness controllability and thickness uniformity. In this article, we briefly review recent research trend on vapor deposition techniques to synthesize 2D TMDCs.

Interfacial electronic structures of metallic nanoparticles on bare- and functionalized-Au nanoisland templates, and on transition metal oxide supports

  • 손영구
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.348-348
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    • 2011
  • We present the interfacial electronic structures of electrodeposited Cu and Fe on bare and 1,4-phenylene diisocyanide (PDI)-functionalized Au nanoisland templates (NITs), and Au and Ag nanoparticles on transition metal oxide supports. Our discussion is based on the depth-profiling X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM).

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전고체전지용 붕산염 유리 세라믹 고체 전해질의 조성비에 따른 소결 특성 연구 (Sintering Behavior of Borate-Based Glass Ceramic Solid Electrolytes for All-Solid Batteries)

  • 이정민;정동석;강성현;;최은하;신원호
    • 한국전기전자재료학회논문지
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    • 제37권4호
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    • pp.445-450
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    • 2024
  • The expansion of lithium-ion battery usage beyond portable electronic devices to electric vehicles and energy storage systems is driven by their high energy density and favorable cycle characteristics. Enhancing the stability and performance of these batteries involves exploring solid electrolytes as alternatives to liquid ones. While sulfide-based solid electrolytes have received significant attention for commercialization, research on amorphous-phase glass solid electrolytes in oxide-based systems remains limited. Here, we investigate the glass transition temperatures and sintering behaviors by changing the molecular ratio of Li2O/B2O3 in borate glass comprising Li2O-B2O3-Al2O3 system. The glass transition temperature is decreasing as increasing the amount of Li2O. When we sintered at 450℃, just above the glass transition temperature, the samples did not consolidate well, while the proper sintered samples could be obtained under the higher temperature. We successfully obtained the borate glass ceramics phases by melt-quenching method, and the sintering characteristics are investigated. Future studies could explore optimizing ion conductivity through refining processing conditions, adjusting the glass former-to-modifier ratio, and incorporating additional Li salt to enhance the ionic conductivity.

Vibronic Assignments of Isomeric Trimethylbenzyl Radicals : Revisited

  • Yi, Eun Hye;Yoon, Young Wook;Lee, Sang Kuk
    • Bulletin of the Korean Chemical Society
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    • 제35권3호
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    • pp.737-742
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    • 2014
  • The vibronic emission spectra of isomeric trimethylbenzyl radicals were reassigned based on substituent effect on electronic transition energy as well as ab initio calculation of the benzyl radical. The electronic transition energy of three isomeric jet-cooled trimethylbenzyl radicals produced by corona discharge of 1,2,3,5-tetramethylbenzene were analyzed using the empirical data of three isomeric methylbenzyl radicals. Calculated data were obtained by summing up the shifts measured from methylbenzyl radicals as well as taking the position and alignment of substituents on the benzene ring into account. The revised assignments show better agreement with observation, and rationalize the validity of the model developed to explain the substituent effect on electronic transition energy of benzyl radicals.

Rietveld 해석법에의한 YBCO 초전도체의 결정 구조 전이 연구 (The crystal structure transition in YBCO superconductor by Rietveld analysis Method)

  • 채기병;전용우;소대화
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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    • pp.239-243
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    • 1996
  • In this paper, we have tried to focus on the optimum conditions of crystal structure parameters on YBCO high Tc oxide-superconductor as an excel lent electronic parts. When we verify the characteristic improvement of superconductance and accurate reproduction and so forth, we have made use of RIETAN. We have varied the lattice constant with oxygen content from 6.0 to 7.0 as for transition of orthogonal structure and tetragonal structure for the superconductor. As the result of above, we have preyed that transition from orthogonal structure to tetragonal structure is made at the point of 6.6(oxygen content) by using the simulation.

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Electronic and Bonding Properties of BaGaGeH: Hydrogen-induced Metal-insulator Transition from the AlB2-type BaGaGe Precursor

  • Kang, Dae-Bok
    • Bulletin of the Korean Chemical Society
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    • 제33권1호
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    • pp.153-158
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    • 2012
  • The hydrogenation of $AlB_2$-type BaGaGe exhibits a metal to insulator (MI) transition, inducing a puckering distortion of the original hexagonal [GaGe] layers. We investigate the electronic structure changes associated with the hydrogen-induced MI transition, using extended H$\ddot{u}$ckel tight-binding band calculations. The results indicate that hydrogen incorporation in the precursor BaGaGe is characterized by an antibonding interaction of $\pi$ on GaGe with hydrogen 1s and the second-order mixing of the singly occupied antibonding $\pi^*$ orbital into it, through Ga-H bond formation. As a result, the fully occupied bonding $\pi$ band in BaGaGe changes to a weakly dispersive band with Ge pz (lone pair) character in the hydride, which becomes located just below the Fermi level. The Ga-Ge bonds within a layered polyanion are slightly weakened by hydrogen incorporation. A rationale for this is given.