• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.1
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• pp.64-68
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• 2001

High quality BSCCO thin films have been fabricated by means of an ion beam sputtering at various substrate temperatures, T$\_$sub/, and ozone gas pressures, PO$_3$. The correlation diagrams of the BSCCO phases appeared against T$\_$sub/ and PO$_3$ are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 phases as well as Bi2212 one come out as stable phases depending on T$\_$sub/ and PO$_3$. From these results, the thermodynamic evaluations of ΔH and ΔS, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase are performed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.104-107
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• 2000

High quality BSCCO thin films have been fabricated by means of an ion beam sputtering at various substrate temperatures, T$\_$sub/, and ozone gas pressures, PO$_3$. The correlation diagrams of the BSCCO Phases appeared against T$\_$sub/ and PO$_3$ are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 phases as well as Bi2212 one come out as stable phases depending on T$\_$sub/ and PO$_3$. From these results, the thermodynamic evaluations of ΔH and ΔS which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase are performed.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.311-315
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• 1991

The formation and transition of 2212 and 2223 phase have been studied in BPSCCO system. The 2212 phase formed in early sintering state reacts on $Ca_2PbO_4,\;Ca_2CuO_3$ and CuO during sintering process and thus produces the 2223 phase. A long sintering period is need to fabricate the superconductor with large volume fraction of 2223 phase. Also, the thin plate-like grains composed of Bi, Sr, Ca and Cu contribute to 2223 phase formation. Though the sample has lower volume fraction of 2223 phase, the critical temperature is measured highly in case of the grain grown to plate-like shape. In this work, the critical temperature of the sample sintered for 264 hr in air was measured 108 K. Microstructure of the sample was varied with condition of heat treatment after sintering process and the sample annealed with $500^{\circ}C$ for 5 hr showed excellent charateristics of 2223 phase formation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.252-255
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• 1996

Superconducting current lead is one of the promising applications of the oxide high-Tc superconductors, because they have the advantage of decreasing heat conduction to low temperature region, comparing with a conventional cooper alloy lead. High critical current density is a key factor for the applications such as current lead. (Bi,Pb)$_2$Sr$_2$Ca$_2$Cu$_3$O$\_$x/ high Tc superconductor haute been investigated in terms of critical current density. Bi-2223 superconducting current lead made by CIP and solid state sintering process. Bi-2223 current lead that heat treated at 836$^{\circ}C$ for 240 h in 1/13 P$\_$O$_2$/ had over 150 A/$\textrm{cm}^2$ of critical current density at 77K. We knew that the superconducting properties of tube type current leads were better than rods type of them. And we investigated the relation of Bi-2223 formation and heat treatment condition by XRD and SEM analysis.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1208-1211
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• 2003

High quality $Bi_2Sr_2Ca_nCu_{n+1}O_x$ superconducting thin films fabricated by using the evaporation method at various substrate temperatures, $T_{sub}$, and ozone gas pressures, $pO_3$. The correlation diagrams of the $Bi_2Sr_2Ca_nCu_{n+1}O_x$ phases with $T_{sub}$ and $pO_3$ are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 as well as Bi2212 phases come out as stable phases depending on $T_{sub}$ and $pO_3$. From these results, the thermodynamic evaluation of ${\Delta}H$ and ${\Delta}S$, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase, was performed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.04a
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• pp.70-73
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• 2006

High quality $Bi_2Sr_2Ca_nCu_{n+1}O_x$ superconducting thin films fabricated by using the evaporation method at various substrate temperatures, $T_{sub}$, and ozone gas pressures, $pO_3$. The correlation diagrams of the $Bi_2Sr_2Ca_nCu_{n+1}O_x$ phases with $T_{sub}$ and $pO_3$ are established in the 2212 arid 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 as well as Bi2212 phases come out as stable phases depending on $T_{sub}$ and $pO_3$. From these results, the thermodynamic evaluation of ${\Delta}H$ and ${\Delta}S$, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase, was performed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.2
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• pp.173-177
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• 2002

High quality BSCCO thin films have been fabricated by means of an ion beam sputtering at various substrate temperatures, T$\sub$sub/, and ozone gas pressures, pO$_3$. The correlation diagrams of the BSCCOphases with T$\sub$sub/ and pO$_3$ are established in the 2212 and 2223 phases come out as stable phases depending on T$\sub$sub/ and pO$_3$. From these results, the thermodynamic evaluation of ΔH and ΔS, which are related with Gibbs\` free energy change for single Bi2212 or Bi2223 phase, were performed.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.02a
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• pp.146-148
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• 2003

SrZrO$_3$ resistive oxide barriers on Ag sheathed Bi2223 monocore tapes were prepared by the sol-gel and dip coating method to reduce AC coupling loss. The performance of the dip-coated SrZrO$_3$ thin films was evaluated in terms of bond strength and surface microstructure by varying the amount of PVP (polyvinylpyrrolidone) binder. Although bond strength and coating thickness increased as the PVP content rose, surface microcracking was more severe for the specimen containing higher content of PVP binder. It suggests that coating thickness and microcracking of the SrZrO$_3$ films on Bi2223 tapes was governed primarily by the amount of PVP binder.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.352-354
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• 2010

The effects of Au addition on the structure and the superconducting properties of Bi system bulk have been investigated. Au exists in the metalic form in above materials. It does not affect the formation and structure of the BiSrCaCuO(2223) phase. The superconducting transition temperature Tc does not change for $Bi_{1.7}Pb_{0.3}Sr_2Ca_2Cu_3O$ composite However Au doping can make the grains smaller. Metallic Au can make gathers on the grains boundary and lead to the increment of critical transport current density. The current density of $Bi_{1.7}Pb_{0.3}Sr_2Ca_2Cu_3Au_{0.5}O$ was 1000A/$cm^2$ at liquid nitrogen temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05b
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• pp.98-101
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• 2005

BSCCO thin films fabricated by using the evaporation method. As a result, although the composition of Bi2212 was set up, the phase of Bi2201, Bi2212 and Bi2223 was formed. The formation area of these stable phases is indicated as inclined line in the direction of the right lower end from the Arrhenius plot of the substrate temperature-oxidation gas pressure, and are distributed in very small area. The activation energy for the phase transformation from the Bi2201 to the Bi2212 is estimated in terms of the Avrami equation.