• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.5
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• pp.464-467
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• 2005

BiSrCaCuO superconducting ceramic thick films were fabricated by chemical process. The x ray diffraction pattern of the BiSrCaCuO thick films contained 110 K phase. The critical temperature of BiSrCaCuO thick films were Tc=95 K-97 K. The critical temperature and critical density of BiSrCaCuO thick film grown at $750 {\circ}C$ were Tc = 95 K and $Jc= 7{\times}10^{6} A/cm^{2}$ We obtained high-Jc as-grown BiSrCaCuO on an MgO substrate by low fressure CVD.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.77-79
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• 1999

Bi$_2$Sr$_2$CaCu$_2$O(Bi-2212) thick films were fabricated on Y211 substrate by screen printing method. The aim of the study was to fabricate superconducting thick films on Y211 substrate by MPMG process. For this study, patterned samples by screen printing method were heated with MPMG process. The thickness of Bi2212 on substrate was about 20 ${\mu}{\textrm}{m}$ and these samples showed many Bi- 2212 phases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.65-68
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• 1999

A well oriented Bi2212 superconductor thick films were fabricated by screen printing with a Cu-free Bi-Sr-Ca-O mixture powder on a copper plate and heat-treating at 820-88$0^{\circ}C$ for several minute in air. During the heat-treatment, the printing layer partially melted by reaction between the Cu-free precursor and CuO of the oxidizing copper plate. In the partial melting state, it is believed that the solid phase is Bi-free phase and Cu-rich phase and the composition of the liquid is around Bi : Sr : Ca : Cu = 2 : 2 : 0 : 1. Following the partial melting, the Bi2212 superconducting phase is formed at Bi-free phase/liquid interface by nucleation and grows. With decreasing the Bi composition in the precursor powder, the critical temperature(T$_{c}$) of the fabricated Bi2212 thick film increased to about 79 K.K.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.503-506
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• 2000

YBCO superconducting thick films were prepared on Ag wire by electrophoresis in acetone and ethanol with chemically modified suspension. The addition of organic compounds, such as PEG, EG into suspension solution for improving critical current density was investigated. Surface state, deposition condition, pore distribution and cracks were investigated by using SEM photographs. Controlling preparation conditions were studied for reducing these defects. As a results, in acetone solution, the surface crack of samples was decreased with increasing PEG. On the contrary, the surface crack of sample was increasing with increasing the amount of EG. In ethanol solution without I$_2$, which was generally used for an electrolyte, the deposition time was longer than this of acetone. For that reason the sample deposition in ethanol time was needed with enough stirring time for suspending YBCO powder and deposition time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1990.10a
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• pp.26-30
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• 1990

Bi$\_$0.7/Pb$\_$0.3/Sr$_1$Ca$_1$Cu$\_$1.8/Ox thick films were screen printed on magnesia(MgO), silver and yttrium stabilized zirconia (YSZ) substrates and were sintered in a boat with cover to prevent the evaporation. The high-Tc phase increase and the low-Tc phase and Ca$_2$PbO$_4$ decrease with an increase in sintering temperature from 835$^{\circ}C$ to 860$^{\circ}C$. YSZ substrate interact strongly with the oxide resulting in poor superconductor, while the Ag and MgO substrates were satisfactory to make screen printed superconductors. The Bi$\_$0.7/Pb$\_$0.3/Sr$_1$Ca$_1$Cu$\_$1.8/Ox thick films screen printed both on Ag and MgO substrates show high Tc phase of ~85% and Tc of 96K.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.81-84
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• 1999

For the research of the effects on suspension solution with YBCO and BSCCO for elcectrophoretic deposition to prepare superconducting thick-film wire, it was investigated that the preheating technique for the superconducting powders in vacuum system was used with various solvent solutions of acetone, ethanol, toluene and buthanol for electrophoresis. As a result it was useful to remove the influence of remaining and adsorbed solvent solution which was existed between and on the particle surfaces when the specimens of superconducting wire by electrophoresis were treated in vacuum of 10$\^$-3/ Torr and temperature around 200$^{\circ}C$ in bell-jar system. From the prepared superconducting wire samples, the critical current density, Jc was measured by 4-point prove method in liquid N$_2$ at the value of 10$\^$3/ to 10$\^$4/ A/$\textrm{cm}^2$, respectively, for the YBCO and BSCCO superconducting wires.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.63-66
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• 2003

The electrophoretic deposition method has the advantage of relatively few fabrication facilities and simple process procedure as well as the economical and technical merit of allowing various forms of deposition and easy control of deposition thickness and wire length. A study, especially electric field and additive, on the optimization method to increase the density of particles and uniformity of their orientation have been performed to overcome the cracking and the porosity problems in the fabricated superconductor.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.242-246
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• 1999

For the fabrication of fault current limiting device using HTSC thick film, YBa$_2Cu_3O_x$ superconducting thick film was formed by surface diffusion process of the Y$_2BaCUO_5$ and the mixed compound of (3BaCuO$_2$+2CuO) expected to be liquid phase above the peritectic temperature of YBa$_2Cu_3O_x$. For the surface diffusion, the compounds of 3BaCuO$_2$+2CuO mixed with binder material was patterned on Y$_2BaCUO_5$ substrate by the screen printing method. After proper sintering, the characteristics of current limit on thick film fabricated was measured. The thick film was able to limit the current from 2.8213 mA$_{rms}$nu to 4.2034 mA$_{rms}$ with 500${\omega}$ load resistance, and from 4.1831 mA$_{rms}$ to 4.2150 mA$_{rms}$ with 10${\omega}$ load resistance.

• Journal of the Korean Ceramic Society
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• v.29 no.2
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• pp.152-160
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• 1992

High-Tc superconductor thick films of YBa2Cu$\chi$O7-y (X=3, 3.5, 4) of which thickness varies from 100 $\mu\textrm{m}$ to 200 $\mu\textrm{m}$ were successfully prepared by plasma spraying method, and the characteristics of thick film depending on copper content and heat treatment conditions were investigated. Regardless of heat-treated temperature, the specimens with X=3 were composed of YBa2Cu$\chi$O7-y, Y2BaCuO5 and BaCuO3 phases. The specimens with X=4, however, were composed of YBa2Cu$\chi$O7-y phase at all heat treatment conditions. The specimens with X=4 composition showed the best superconducting characteristics after heat treatment at 925$^{\circ}C$, and the superconducting transition temperature with zero resistivity (Tc,zero) was 87K. The thick film lost superconductivity when the specimens were heat-treated at 950$^{\circ}C$ because of interdiffusion between superconductor elements and bond coating elements and Y2BaCuO5 phase was found was found to be main phase at the interface.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.6
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• pp.9-15
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• 2004

PZT(30/70) thick film was fabricated by using 1,3 propanediol-based sol-gel method. Prepared film of pyroelectric property was investigated by Dynamic method of modulation frequency dependence. Pyroelectric coefficient was obtained about $5.0{\times}10^{-8}\;C/cm^2{\cdot}K$. The figure of merits for voltage responsively and specific detectivity were $3.4{\times}10^{-11}\;C{\cdot}cm/J$ and $5.9{\times}10^{-9}\;C{\cdot}cm/J$, respectively, because of relative high-dielectric constant and high-pyroelectric coefficient. Voltage responsively was increased at low modulation frequency and it was decreased at high modulation frequency. Voltage responsively was maximum 1.84 V/W at 10Hz. As Johnson noise is dominant, Noise voltage was increased nearly proportional to $f^{-1/2}$. Noise equivalent power and specific detectivity were $2.83{\times}10^{-7}\;W/Hz^{1/2}$ and 3.13{\times}10^5\;cm{\cdot}Hz^{1/2}/W$ the same frequency at 80Hz, respectively.