• Title/Summary/Keyword: Oxide superconductors

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Fabrication of BSCCO high-Tc superconducting current lead (BSCCO 고온초전도 전류도입선의 제조)

  • 하동우;오상수;류강식;장현만
    • 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.

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Microstructure and Properties of High Tc Superconductor fabricated by Hot Isostatic Pressing (열간정수압소결(HIP) 시킨 고온초전도체의 조직과 특성)

  • Song, Jin-Tae;Akihama, Ryozo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1988.05a
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    • pp.17-19
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    • 1988
  • $YBa_2Cu_3O_{7-x}$ oxide superconductors were fabricated by the hot isostatic pressing (HIP). It was shown that their structures were orthorombic and constited of a single (123) phase. While as-sintered compacts had many pores, they were remarkably reduced by Hiping. The on-set and off set temperature of (123) compound sintered at $950^{\circ}C$ in oxygen and hiping at $880^{\circ}C$ were the highest and it showed 0 resistance at $90^{\circ}K$. The critical current density ($J_c$) of the above superconductor was $27A/cm^2$ and it also showed a number of twin structures, which are typical of high $T_c$ superconductor. It seemed that the low current density may be due to the many pores of starting-sintered compacts.

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Formation of $YBa_2Cu_3O_x$ and the microstructure of melt infiltration processed YBCO superconductors

  • Kim, C.J.;Lee, D.M.;Park, H.S.;Jee, Y.A.;Hong, G.W.
    • Progress in Superconductivity
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    • v.1 no.2
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    • pp.89-94
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    • 2000
  • A YBCO superconductor was prepared in a short time by a melt infiltration process that utilizes meting of $Ba_3Cu5O_8$ powder and the infiltration into a porous $Y_2BaCuO_5$ compact. The processing parameters such as a reaction temperature and time, and atmosphere (air and $O_2$) were controlled to establish the fabrication condition. The formation of a $YBa_2Cu_3O_x$, phase and the developed microstructure are reported.

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Effect of Metal Oxide on the Superconductivity of YBCO

  • Lee, Sang-Heon
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1241-1242
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    • 2006
  • Electromagnetic properties of $CeO_2$ doped and undoped YBaCuO superconductors were evaluated to investigate the effect of pinning center on the magnetization and magnetic shielding. The variation $\DeltaM$ with doping was maximum for 3% doping and decrease with further doping. The magnetic shielding was evaluated by measuring the induced voltage in secondary coil and the voltage initially set to 0.5V, decreased to 0.17V and 0.28V respectively for the undoped and 3% $CeO_2$ doped sample. The much less change in the induced voltage for the 3% doped sample is attributed to the increased flux shielding by shielding vortex current. The $CeO_2$ was converted to fine $BaCeO_3$ particles which were trapped in YBaCuO superconductor during the reaction sintering. The trapped fine particles, $BaCeO_3$ may be acted as a flux pinning center.

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Lattice strain effects on superconductivity in $La_{2-x}Sr_{x}CuO_{4}$ single-crystalline films grown by IR-LPE technique

  • Tanaka, I.;Islam, A.T.M.N.;Wataudhi, S.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.13 no.4
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    • pp.172-175
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    • 2003
  • We have investigated effects of the lattice mismatch between the LPE films and the substrates. We have grown $La_{2-x}Sr_{x}CuO_{4}$(x=0.1 to 0.15) single crystalline films on single crystalline substrates having different lattice parameter ratio c/a e.g., $La_{2-x}Sr_{x}Cu_{1-y}Zn_{y}O_{4},\;La_{2-x}Ba_{x}CuO_{4},\; LaSrAlO_{4}\;and\;La_{2-x}Sr_{x}Cu_{1-y}Al_{y}O_{4}$ etc., using the IR-LPE technique. The superconducting properties of the grown films were found to vary significantly depending on the lattice mismatch with different substrates.

Effects of Substrate and Sintering Conditions on the Properties of Screen Printed Bi-Pb-Sr-Ca-Cu-O Superconduction Thick Films (Screen printing 방법에 의한 후막형 Bi-Pb-Sr-Ca-Cu-O 초전도체의 소결조건과 기판의 초전도성에 미치는 영향)

  • 김혜동;임호빈
    • 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.

Fabrication of Bulk High-Tc Superconductor (벌크형 고온 초전도 합성)

  • Lee, Sang Heon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.34 no.5
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    • pp.333-336
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    • 2021
  • Oxide YBCO bulk superconductors are manufactured using the melt process. Because seed crystal growth method utilizes a slow-spreading layer-by-layer reaction, a long-term heat treatment is required to manufacture a single-crystal specimen of several cm. In this study, the melt process method was applied to compensate for the shortcomings of the seed crystal growth method. The thickness of the upper and lower pellets of the YBCO bulk was molded to 40 mm, and YBCO superconductor was produced by heat treatment. The measurement results of capture magnetism was in line with the literature. This results in a relationship that the higher the growth of Y211 particle in the YBCO, the higher the superconducting properties. We analyzed the YBCO superconductor, focusing on the Y2BaCuO5 particle distribution.

Characteristics of Plasma Sprayed BSCCO Superconductor Coatings with Annealing Time After Partial Melt Process (BSCCO 플라즈마 용사피막의 부분용융열처리 후 어닐링 시간에 따른 초전도 특성)

  • Park, Jeong-Sik;Lee, Seon-Hong;Park, Kyeung-Chae
    • Korean Journal of Materials Research
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    • v.24 no.2
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    • pp.116-122
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    • 2014
  • $Bi_2Sr_2CaCu_2O_x$(Bi-2212) and $Bi_2Sr_2Ca_2Cu_3O_y$(Bi-2223) high-Tc superconductors(HTS) have been manufactured by plasma spraying, partial melt process(PMP) and annealing treatment(AT). A Bi-2212/2223 HTS coating layer was synthesized through the peritectic reaction between a 0212 oxide coating layer and 2001 oxide coating layer by the PMP-AT process. The 2212 HTS layer consists of whiskers grown in the diffusion direction. The Bi-2223 phase and secondary phase in the Bi-2212 layer were observed. The secondary phase was distributed uniformly over the whole layer. As annealing time goes on, the Bi-2212 phase decreases with mis-orientation and irregular shape, but the Bi-2223 phase increases because a new Bi-2223 phase is formed inside the pre-existing Bi-2212 crystals, and because of the nucleation of a Bi-2223 phase at the edge of Bi-2212 crystals by diffusion of Ca and Cu-O bilayers. In this study the spray coated layer showed superconducting transitions with an onset Tc of about both 115 K, and 50 K. There were two steps. Step 1 at 115 K is due to the diamagnetism of the Bi-2223 phase and step 2 at 50 K is due to the diamagnetism of the Bi-2212 phase.

Development of Superconducting Materials Property Database (초전도 재료물성 데이터베이스 개발)

  • 이정구;이상호;김창규;김지영;한정민;김태중
    • Proceedings of the Korea Contents Association Conference
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    • 2003.05a
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    • pp.291-297
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    • 2003
  • With the development of information communication technology, the demands for various, profound and advanced information on science and technology and the necessity for establishing science and technology information infrastructure with the aim of future oriented industry are ever increasing. Advanced countries are providing material property DB as well as bibliographic DB though the Internet. Establishment and dissemination of bibliographic DB at domestic is properly settled but research on material property DB is much to be desired. Accordingly, development and research on material property DB to construct the information infrastructure in science and technology are highly necessary. In this study, we have developed superconducting materials property DB which is highly advanced industry field in future. We provide the thermal and mechanical, and superconducting property data for oxide superconductors, and the database is designed by bibliographic information, material information and material property information section.

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Fabrication of Bi-2223 high-Tc superconducting current lead (Bi-2223 고온초전도 전류리드의 제조)

  • Ha, D.W.;Oh, S.S.;Ryu, K.S.;Chang, H.M.
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1660-1662
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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 hase 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 $PO_2$ had over $500\;A/cm^2$ 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.

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