• 한국결정학회지
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• 제7권2호
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• pp.147-155
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• 1996

할로겐 램프를 열원으로 이용하는 결정성장장치인 부유대역융로를 제작하여 고온초전도체 Bi2Sr2CaCu2O8의 성장에 이용하였다. 제작된 결정성장장치는 할로겐 램프를 초점에 위치시키기 위한 holder unit, 1kW의 할로겐 램프로서 최대 1800℃까지 사용이 가능한 image furnace, 냉각장치, 원료 물질을 공급하는 feeding unit, 성장된 단결정을 인상하는 pulling unit, 그리고 2mm/hr - 40mm/hr의 속도로 상하 이동 및 15rpm -120rpm의 회전이 가능한 제어부 등으로 구성되었다. 300W의 할로겐 램프를 이용하여 Bi2Sr2CaCu2O8 fiber를 성장시켰으며 성장된 fiber는 XRD, SEM, EDS 등으로 분석하였다. 성장조건은 공기분위기에서 성장속도 3∼4mm/hr, 상·하부축 회전속도 20∼25 rpm이었으며 성장된 fiber는 Bi2Sr2CaCu2O8 기지 내에 (Sr,Ca)CuO2 및 (Sr,Ca)2CuO3의 2차상을 포함하고 있었다.

• 한국세라믹학회지
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• 제26권6호
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• pp.747-754
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• 1989

The effects of CuO and SiO2 on the sintered density, grain growth and magnetic properties of Sr-ferrite were investigated. The sintered density of Sr-ferrite is increased with increasing the amount of CuO or SiO2 addition. The grain of Sr-ferrite grow uniformly with the addition of CuO, so remanence increases and coercivity decreases. The addition of SiO2 increase coercivity but does not affect remanence prominently. The sintering temperature above 125$0^{\circ}C$ and SiO2 addition above 0.8wt% causes abnormal grain growth in Sr-ferrite. When CuO and SiO2 are added simultaneouly, remanence does not decrease but coercivity shows low value.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.69-72
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• 1999

A Well oriented Bi$_2$re$_2$CaCu$_2$O$\sub$8/(Bi2212) superconductor thick films were formed successfully on a copper substrate by liquid reaction between a Cu-free precursor and Cu tape using method in which Cu-free BSCO powder mixture was printed on copper plate and heat-treated. And we examined the mechanism for the rapid formation of Bi2212 superconducting films from observing the surface microstructure with heat-treatment time. At heat-treatment temperature, the printing layer partially melt by reacting with CuO of the oxidizing copper plate, and the nonsuperconducting phases present in the melt are typically Bi-free phases and Cu-free phases. Following the partial melting, the Bi$_2$Sr$_2$CaCu$_2$O$\sub$8/ superconducting phase is formed at Bi-free phase/liquid interface by nucleation and grows. It was confirmed that the phase colony from the phase diagram of Bi$_2$O$_3$-(SrO+CaO)/2-CuO system is similar to the observed result.

• 한국재료학회지
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• 제29권1호
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• pp.1-6
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• 2019

Recent industrialization has led to a high demand for the use of fossil fuels. Therefore, the need for producing hydrogen and its utilization is essential for a sustainable society. For an eco-friendly future technology, photoelectrochemical water splitting using solar energy has proven promising amongst many other candidates. With this technique, semiconductors can be used as photocatalysts to generate electrons by light absorption, resulting in the reduction of hydrogen ions. The photocatalysts must be chemically stable, economically inexpensive and be able to utilize a wide range of light. From this perspective, cuprous oxide($Cu_2O$) is a promising p-type semiconductor because of its appropriate band gap. However, a major hindrance to the use of $Cu_2O$ is its instability at the potential in which hydrogen ion is reduced. In this study, gold is used as a bottom electrode during electrodeposition to obtain a preferential growth along the (111) plane of $Cu_2O$ while imperfections of the $Cu_2O$ thin films are removed. This study investigates the photoelectrochemical properties of $Cu_2O$. However, severe photo-induced corrosion impedes the use of $Cu_2O$ as a photoelectrode. Two candidates, $TiO_2$ and $SnO_2$, are selected for the passivation layer on $Cu_2O$ by by considering the Pourbaix-diagram. $TiO_2$ and $SnO_2$ passivation layers are deposited by atomic layer deposition(ALD) and a sputtering process, respectively. The investigation of the photoelectrochemical properties confirmed that $SnO_2$ is a good passivation layer for $Cu_2O$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.291-294
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• 2000

The crystallization behavior and dc Conductivities of CuO-P$_2$O$_{5}$ -Nb$_2$O$_{5}$ -V$_2$O$_{5}$ glasses prepared by quenching on the copper plate were investigated. The conductivities of the glasses were range from 10$^{-5}$ s.$cm^{-1}$ / at room temperature, but the conductivities of the glass-ceramics were 10$^{-3}$ s.$cm^{-1}$ / increased by 10$^2$order. The crystalline product in the glass-ceramics was CuV$_2$O$_{6}$ . The linear relationship between in($\sigma$T) and T$^{-1}$ suggested that the electrical conduction in the present glass-ceramics would be due to a small polaron hopping mechanism.

• Korean Chemical Engineering Research
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• 제43권1호
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• pp.140-145
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• 2005

본 연구에서는 주 반응물질로 CuO를 사용하고, $Fe_2O_3$의 함량을 7.5 wt%, 15 wt%, 22.5 wt%로 변화시키고, 지지체 $SiO_2$의 함량을 25 wt%로 고정하여 흡수제를 제조하였다. 특히 소성온도의 변화에 따른 흡수제의 탈황성능의 변화를 조사하기 위하여, 흡수제의 소성 온도를 700, 900 그리고 $1,100^{\circ}C$로 달리하여 흡수제를 제조하였다. 제저된 흡수제는 GC/소형반응기를 이용하여 사이클 실험을 하였으며, 이때 흡수제의 황화온도는 $500^{\circ}C$, 재생온도는 $700^{\circ}C$로 하였다. 반응 전후의 XRD 분석을 통하여 화합물의 형태를 확인하였으며, BET 분석을 통하여 소성온도의 변화에 따른 흡수제의 표면적 변화를 조사하였다. 또한, 장기사이클에서 $700^{\circ}C$에서 소성된 CFS3 흡수제(CuO : $Fe_2O_3$ : $SiO_2$=52.5 wt% : 22.5 wt% : 25 wt%)의 $H_2O$의 유/무에 따른 탈황성능의 변화를 확인하였다. 그 결과 소성온도에 따른 비표면적의 변화는 크게 나타나지 않았다. 또한, 장기사이클에서 $H_2O$에 의한 탈황성능의 저하를 확인할 수 있었다. 특히 $1,100^{\circ}C$에서 소성된 CFS1 흡수제(CuO : $Fe_2O_3$ : $SiO_2$=67.5 wt% : 7.5 wt% : 25 wt%)의 경우에는 $H_2O$가 존재함에도 불구하고, 100 사이클이 지난 후에도 흡수제 100 g당 10 g의 황을 제거할 수 있는 탈황성능을 보였다.

• 한국세라믹학회지
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• 제32권9호
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• pp.1056-1064
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• 1995

95Pb(Mg1/3Nb2/3)O3-5PbTiO3 (hereinafter designated as 95PMN-5PT) system was prepared by the columbite-precursor method with 2 mol% excess PbO to compensate the PbO loss during thermal process. The amount of CuO was 1~10 mol%, and the effects of CuO addition on the dielectric properties of this system have been investigated. From the microstructures, XRD analysis and dielectric measurements, the solubility limit of CuO in 95PMN-5PT was found to be around 3 mol%. Lattice parameter and Curie temperature were found to be decreased as the amount of CuO increased up to the solubility limit. This result confirmed that the Cu2+-ions substituted the Pb2+-ions. It was revealed that the addition of CuO on 95PMN-5PT promoted the sinterability and properties. The room temperature dielectric constant, the loss factor and the specific resistivity of the specimens processed with optimum conditions were 23000, 1%, and 8$\times$1011Ω.cm, respectively.

• 한국재료학회지
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• 제33권9호
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• pp.367-371
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• 2023

In this study we examine variations in the structure of perovskite compounds of LaBa₂Cu₂O₉, LaBa2₂CaCu₃O₁₂ and LaBa₂Ca₂Cu₅O₁₅ synthesized using the solid state reaction method. The samples' compositions were assessed using X-ray fluorescence (XRF) analysis. The La: Ba: Ca: Cu ratios for samples LaBa₂Cu₂O₉, LaBa2₂CaCu₃O₁₂ and LaBa₂Ca₂Cu₅O₁₅ were found by XRF analysis to be around 1:2:0:2, 1:2:1:3, and 1:2:2:5, respectively. The samples' well-known structures were then analyzed using X-ray diffraction. The three samples largely consist of phases 1202, 1213, and 1225, with a trace quantity of an unknown secondary phase, based on the intensities and locations of the diffraction peaks. According to the measured parameters a, b, and c, every sample has a tetragonal symmetry structure. Each sample's mass density was observed to alter as the lead oxide content rose. Scanning electron microscope (SEM) images of the three phases revealed that different Ca-O and Cu-O layers can cause different grain sizes, characterized by elongated thin grains, without a preferred orientation.

• Bulletin of the Korean Chemical Society
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• 제11권6호
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• pp.564-567
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• 1990

A lithiated compound $Li_{0.1}Pr^{3+}Ba_2Cu_3O_y$ has been successfully prepared by electrochemical method, which is achieved with a two electrode cell of the type: Metal(Li)/($Li^+\;,\;ClO_4^-$) + propylene carbonate/$PrBa_2Cu_3O_y$. All Pr ions in the lithiated compound are stabilized with a trivalent state as the other rare earths (Ⅲ) substituted in the 90K superconductor lattice ($Y_{1-x}Ln_x^-Ba_2Cu_3O_{7-{\delta}}$). Powder X-ray diffraction analysis shows that both compounds, $PrBa_2Cu_3O_y$ and $Li_{0.1}PrBa_2Cu_3O_y$ are isostructural with the 90 K superconductor, ($YBa_2Cu_3O_{7-{\delta}}$), nevertheless both of them are non-metallic and also non-superconducting down to 10 K. Magnetic susceptibility ${\chi}$ vs. temperature data indicate that Curie contribution from the magnetic ions (Pr and Cu) is weakened on the one hand, but on the other hand temperature-independent part of susceptibility ${\chi}_o$ increases depending upon the rate of lithium intercalation in $PrBa_2Cu_3O_y$ lattice.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.934-937
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• 2003

Glasses in the system $CuO-P_2O_5-V_2O_5$ were prepared by a press-quenching method on the copper plate. The glass-ceramics from these glasses were obtained by post-heat treatment, and the crystallization behavior and DC conductivities were determined. The conductivities of the glasses were range from $10^{-6}s.Cm^{-1}$ at room temperature, but the conductivities of the glass-ceramics were $10^{-3}s.Cm^{-1}$ increased by $10^3$ order. The crystalline product in the glass-ceramics was $CuV_2O_6$. Heat-treatment conditions influenced the crystal growth of $CuV_2O_6$ and conductivity. The linear relationship between in (${\sigma}T$) and $T^{-1}$ suggested that the electrical conduction in the present glass-ceramics would be due to a small polaron hopping(SPH) mechanism.