• 한국재료학회지
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• 제14권11호
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• pp.802-806
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• 2004

Skutterudite $CoSb_3$ powders were produced by mechanical alloying (MA) of elemental powders using a nominal stoichiometric composition. Annealing of MA powders under specific condition led to a complete phase transformation to a semiconducting ${\delta}-CoSb_3$. Single phase $CoSb_3$ was successfully produced by vacuum hot pressing using MA powders without subsequent annealing. Phase transformations during mechanical alloying and hot pressing were systematically investigated using XRD and SEM. Thermoelectric properties as a function of temperature were evaluated for the hot pressed specimens and compared with results of analogous studies.

• 한국세라믹학회지
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• 제33권12호
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• pp.1301-1310
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• 1996

Generally it requires high sintering temperatures more than 135$0^{\circ}C$ to make semiconductive BaTiO3 ceramics. Also it is very difficult to achieve a homogeneous mixing in solid-state reaction method. Therefore the liquid phase distributed to non-uniform dilute the characteristics of PTCR. In order to improve the uniformity this study is used the sol-gel coating method. Using this method we studied the new manufacturing process that had a high reproducibility and mass production capability. Tetraethyl orthosilicate (TEOS) was used as a source of Si. The semiconductive BaTiO3 ceramics which was produced by sol-gel method for the SiO2 addition and sintered between 124$0^{\circ}C$ and 130$0^{\circ}C$ showed almost same resistivity at room temperature among 125$0^{\circ}C$ and 130$0^{\circ}C$. As the results We could be sintered the semiconducting BaTiO3 ceramics at lower temperature even at 125$0^{\circ}C$ maintaining the same specific resistivity ratio ($\rho$max/$\rho$min) at 130$0^{\circ}C$. The specific resistivity both below and above the Curie temperature were increased by slow cooling and the steepness of the plots in the reasion of transition from low to high resistance increased as the cooling rate decreased.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.230-233
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• 2001

FeSi2/Si Layer were grown using FeSi2, Si wafer by the chemical transport reactio nmethod. The directoptical energy gap was found to be 0.871eV at 300 K. The Hall effect is a physical effect arising in matter carrying electric current inthe presence of a magnetic field. The effect is named after the American physicist E. H. Hall, who discovered it in 1879. IN this paper, we study electrical properties of FeSi2/Si layer. And then we measured Hall coefficient Hall mobility, carrier density and Hall voltage according to variation magnetic field and temperature, Because of important part for it applicationVarious phase of silicide is formed at the metal-Si interface when transition metal contacts to Si. Silicides belong to metallic or semiconducting according to their electrical and optical properties. Metallic silicides are used as gate electrodes or interconnections in VLSI devices. Semiconducting silicides can be used as a new material for IR detectors because of their narrow energy band gap.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.234-237
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• 2001

FeSi2/Si Layer were grown using FeSi2, Si wafer by the chemical transport reactio nmethod. The directoptical energy gap was found to be 0.871eV at 300 K. The Hall effect is a physical effect arising in matter carrying electric current inthe presence of a magnetic field. The effect is named after the American physicist E. H. Hall, who discovered it in 1879. IN this paper, we study electrical properties of FeSi2/Si layer. And then we measured Hall coefficient Hall mobility,carrier density and Hall voltage according to variation magnetic field and temperature, Because of important part for it applicationVarious phase of silicide is formed at the metal-Si interface when transition metal contacts to Si. Silicides belong to metallic or semiconducting according to their electrical and optical properties. Metallic silicides are used as gate electrodes or interconnections in VLSI devices. Semiconducting silicides can be used as a new material for IR detectors because of their narrow energy band gap.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
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• pp.25-28
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• 2001

The objectives of this paper are to demonstrate the electrical degradation phenomena with Si atom's behaviors in the grainboundary of semiconducting ZnO ceramics. The ZnO ceramic devices used in this investigation were fabricated by standard ceramic techniques. Especially, $SiO_2$ were added to analyze the degradation characteristics with Si and sintered in oxygen ambient at $1300^{\circ}C$. The conditions of DC degradation test were $115{\pm}2^{\circ}C$ for 13h. Using XRD and SEM, the phase and microstructure of samples were analyzed respectively. E-J analysis was used to determine $\alpha$. Frequency analysis was accomplished to understand $R_g$ and $R_b$ at the equivalent circuit. Electrical stability improved as the amount of $SiO_2$ addition increased. This results were explain by the quantitative analysis and the line scanning method of EPMA.

• 한국세라믹학회지
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• 제32권5호
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• pp.567-574
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• 1995

The effect of MnO2 addition to 0.1mol% Sb2O3-doped BaTiO3 ceramics on microstructure and PTCR characteristics was studied. The PTCR characteristics was observed when 0.01 and 0.02 wt% MnO2 were added and sintered at 132$0^{\circ}C$ for 1 hour. The characteristics can be explained by the changes in the number and size of the abnormal grain growth due to the liquid phase during sintering. when the amount of MnO2 addition was 0.03 wt%, the sample showed NTCR characteristics with room-temperature resistivity over 109 Ωm regardless of the sintering temperature. This behavior can be described by the microstructure change due to the abnormal grain growth and charge compensation effect by MnO2 added. The room-temperature resistivity was increased as the amount of MnO2 was increased. And the specific resistivity ratio (pmax/pmin) showed maximum at 0.02wt% MnO2.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.234-237
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• 2001

FeSi$_2$/Si Layer were grown using FeSi$_2$, Si wafer by the chemical transport reaction method. The directoptical energy gap was found to be 0.871ev at 300 K. The Hall effect is a physical effect arising in matter carrying electric current in the presence of a magnetic field. The effect is named after the American physicist E. H. Hall, who discovered it in 1879. In this paper, we study electrical properties of FeSi$_2$/Si layer And then we measured Hall coefficient Hall mobility, carrier density and Hall voltage according to variation magnetic field and temperature, Because of important Part for it application Various phase of silicide is formed at the metal-Si interface when transition metal contacts to Si. Silicides belong to metallic or semiconducting according to their electrical and optical properties. Metallic silicides are used as gate electrodes or interconnections in VLSI devices. Semiconducting silicides can be used as a new material for IR detectors because of their narrow energy band gap.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.230-233
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• 2001

FeSi$_2$ Layer were grown using FeSi$_2$, Si wafer by the chemical transport reaction method. The directoptical energy gap was found to be 0.87leV at 300 K. The Hall effect is a Physical effect arising in matter carrying electric current in the presence of a magnetic field. The effect is named after the American physicist E.H. Hall, who discovered it in 1879. In this paper, we study electrical properties of FeSi$_2$/Si layer. And then we measured Hall coefficient Hall mobility, carrier density and Hall voltage according to variation magnetic field and temperature, Because of important part for it application various phase of silicide is formed at the metal-Si interface when transition metal contacts to Si. Silicides belong to metallic or semiconducting according to their electrical and optical properties. Metallic silicides are used as gate electrodes or interconnections in VLSI devices. Semiconducting silicides can be used as a new material for IR detectors because of their narrow energy band gap.

• 한국분말재료학회지
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• 제15권5호
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• pp.345-351
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• 2008

The effects of the dopant (Mn) ratio on the microstructure and thermoelectric properties of $FeSi_2$ alloy were studied in this research. The alloy was fabricated by a combination process of ball milling and high pressure pressing. Structural behavior of the sintered bulks were systematically investigated by XRD, SEM, and optical microscopy. With increasing dopan (Mn) ratio, the density and ${\varepsilon}-FeSi$ phase of the sintered bulks increased and maximum density of 94% was obtained in the 0.07% Mn-doped alloy. The sintered bulks showed fine microstructure of ${\alpha}-Fe_{2}Si_{5}$, ${\varepsilon}-FeSi$ and ${\beta}-FeSi_2$ phase. The semiconducting phase of ${\beta}-FeSi_2$ was transformed from ${\alpha}-Fe_{2}Si_{5}+{\varepsilon}-FeSi$ phase by annealing.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.27.2-27.2
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• 2011

Polymer electronics is the one of the most promising way to realize the flexible electronics and many studies made remarkable progress to achieve the improvement in performance of polymer electronics comparable to current silicon-based technology. PBTTT is conjugated semiconducting polymer with highly ordered, chain-extended crystalline microstructures and shows high field effect mobilities above 0.1 $cm^2/Vs$. We studied PBTTTs FETs phase and explored methods to control channel interface in various device structures. Especially, in PBTTTs' unique nano-ribbon phase, we could obtain high mobilities of up to 0.4 $cm^2/Vs$, which was not reached before. Alignment of PBTTTs film was carried out using zone casting and anisotropy of mobilities in parallel and perpendicular to the polymer chain direction was investigated. Optical anisotropy in aligned nano-ribbon PBTTT FETs was also studied using a polarized optical absorption.