• Title/Summary/Keyword: Bi2201 Superconductor

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Layer-by-layer Deposition of BSCCO Thin Films Using Ion Beam Sputtering Method (이온 빔 스퍼터법에 의한 BSCCO 박막의 순차 증착)

  • 박용필;이준웅
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.4
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    • pp.334-339
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    • 1998
  • $Bi_2Sr_2CuO_x$(Bi-2201) thin films have been fabricated by atomic layer-by-layer deposition using ion beam sputtering (IBS) method. During the deposition, 14 wt%-ozone/oxygen mixture gas of typical pressure of $5.0\times10^{-5}$ Torr is supplied with ultraviolent light irradiation for oxidation. XRD and RHEED investigations reveal that a buffer layer with compositions different from Bi-2201 is formed at the early deposition stage of less than 10 units cell and then Bi-2201 oriented along the c-axis is grown.

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Phase Stability of Bi-2212 and Bi-2223 Thin Films Prepared by IBS Technique

  • Yang, Sung-Ho;Park, Yong-Pil
    • Transactions on Electrical and Electronic Materials
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    • v.2 no.1
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    • pp.12-15
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    • 2001
  • Bi-2212 and Bi-2223 thin films are prepared by IBS(ion beam sputtering) technique. Three phases of Bi-2201, Bi-2212 and Bi-2223 appear as stable ones in spite of the conditions for thin film fabrication of Bi-2212 and Bi-2223 compositions, depending on substrate temperature (T $_{sub}$) and ozone pressure(PO$_3$). It is found out that these phases are limited within very narrow temperature.e.

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Phase Stability Region of Bi-superconductor Thin Films Prepared by IBS Technique (이온빔 스퍼터법으로 제작한 Bi 초전도 박막의 상안정 영역)

  • Lim, Jung-Kwan;Chun, Min-Woo;Park, Yong-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.308-311
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    • 2001
  • Bi-2212 and Bi-2223 thin films are prepared by IBS(ion beam sputtering) technique. Three phases of Bi-2201, Bi-2212 and Bi-2223 appear as stable ones in spite of the conditions for thin film fabrication of Bi-2212 and Bi-2223 compositions, depending on substrate temperature($T_{sub}$) and ozone pressure( $PO_3$ ). It is found out that these phases show similar $T_{sub}$ and $PO_3$ dependence, and that the stable regions of these phases are limited within very narrow temperature.

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Phase Stability Region of Bi-superconductor Thin Films Prepared by IBS Technique (이온빔 스퍼터법으로 제작한 Bi 초전도 박막의 상안정 영역)

  • 임중관;천민우;박용필
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.308-311
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    • 2001
  • Bi-2212 and Bi-2223 thin films are prepared by IBS(ion beam sputtering) technique. Three phases of Bi-2201, Bi-2212 and Bi-2223 appear as stable ones in spite of the conditions for thin film fabrication of Bi-2212 and Bi-2223 compositions, depending on substrate temperature($T_{sub}$) and ozone pressure(PO$_3$). It is found out that these phases show similar $T_{sub}$ and PO$_3$ dependence, and that the stable regions of these phases are limited within very narrow temperature.

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SI(superconductor-insulator) Transitions in Bi-superconducting Mixed Crystal Thin Films

  • Park, No-Bong;Yang, Sung-Ho;Park, Yong-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.486-489
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    • 2002
  • Temperature(T) dependence of the sheet resistance( $R_{$\square$}$) has been investigated on the c-axis oriented thin films of the (Bi2212/Bi2201) mixed crystal with different molar fractions. The $R_{$\square$}$-T superconducting characteristic deteriorated with reduction of the Bi2212 fraction, and almost disappears at 48 mol% where a superconductor-to-insulator transition took place, with the resistance on the normal state, RN, reaching 4.l㏀ at 80 K. This $R_{N}$ value is close to the universal quantum number, h/(2e)$^2$≡6.5㏀ predicted by the Kosterlitz-Thouless(KT) transition theory. The $R_{$\square$}$-T characteristics of the 48 mol% thin film can be elucidated as a competitive process of KT transition brought about by charge or vortex in the two-dimensional layer structure.e.

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Characteristics of Co-deposition for Bi-superconductor Thin Film Using Ion Beam Sputtering Method (IBS 법으로 제작한 Bi 계 초전도 박막의 동시 증착 특성)

  • 박용필;이준웅
    • Electrical & Electronic Materials
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    • v.10 no.5
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    • pp.425-433
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    • 1997
  • BSCCO thin films have been fabricated by co-deposition at an ultralow growth rate using ion beam sputtering(IBS) method. The growth rates of the films was set in the region from 0.17 to 0.27 nm/min. MgO(100) was used as a substrate. In order to appreciate stable existing region of Bi 2212 phase with temperature and ozone pressure, the substrate temperature was varied between 655 and 82$0^{\circ}C$ and the highly condensed ozone gas pressure(PO$_3$) in vacuum chamber was varied between 2.0$\times$10$^{-6}$ and 2.3$\times$10$^{-5}$ Torr. Bi 2212 phase appeared in the temperature range of 750 and 795$^{\circ}C$ and single phase of Bi 2201 existed in the lower region than 785$^{\circ}C$. Whereas, PO$_3$dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with T$_{c}$(onset) of about 90 K and T$_{c}$(zero) of about 45 K is obtained. Only a small amount of CuO in some films was observed as impurity, and no impurity phase such as CaCuO$_2$was observed in all of the obtained films.lms.

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Phase Stability of Bi2212 and Bi2223 Thin Films Fabricated by Ion Beam Sputtering

  • Lee, Hee-Kab;Park, Yong-Pil;Kim, Jeong-Ho
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2000.11a
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    • pp.108-111
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    • 2000
  • Bi2212 and Bi2223 thin films are fabricated by ion beam sputtering method. Three phases of Bi2201, Bi2212 and Bi2223 appear as stable ones in spite of the condition for thin film fabrication of Bi2212 and bi2223 compositions, depending on substrate temperature(T$\sub$sub/) and ozone pressure (PO$_3$). It is found out that these phases show similar T$\sub$sub/ and PO$_3$dependence, and that the stable regions of these phases are limited within very narrow temperature.

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Phase Stability of Bi2212 and Bi2223 Thin Films Fabricated by ion Beam Sputtering

  • Lee, Hee-Kab;Park, Yong-Pil;Kim, Jeong-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.108-111
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    • 2000
  • Bi2212 and Bi2223 thin films are fabricated by ion beam sputtering method. Three phases of Bi2201, Bi2212 and Bi2223 appear as stable ones in spite of the condition for thin film fabrication of Bi2212 and bi2223 compositions, depending on substrate temperature(T$\sub$sub/) and ozone pressure (PO$_3$). It is found out that these phases show similar T$\sub$sub/ and PO$_3$ dependence, and that the stable regions of these phases are limited within very narrow temperature.

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Analysis of Thermodynamic Conditions for Formation of Single Phase in Bi-superconductor Thin Films (Bi 초전도 박막에서 단일상 형성을 위한 열역학 초건 분석)

  • 안준호;박용필;김정호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.304-307
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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$\sub$sub/, and ozone gas pressures, PO$_3$. The correlation diagrams of the BSCCO Phases appeared against T7ub and PO3 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$\sub$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.

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Superconducting Characteristics of Bi Thin Films Fabricated by Ion Beam Sputtering (이온빔 스퍼터법으로 제작한 Bi 박막의 초전도 특성)

  • 이희갑;박용필;오금곤
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.222-225
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    • 2000
  • BSCCO thin films have been fabricated by co-deposition at an ultralow growth rate using ion beam sputtering(IBS) method. Bi 2212 phase appeared in the temperature range of 750 and $795^{\circ}C$ and single phase of Bi 2201 existed in the lower region than $785^{\circ}C$. Whereas, $Po_3$ dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with $T_c$ (onset) of about 90 K and $T_c$(zero) of about 45 K is obtained. Only a smd amount of CuO in some films was observed as impurity, and no impurity phase such as $CaCuO_2$ was observed in d of the obtained films.

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