• Title/Summary/Keyword: $YBa_2Cu_3O_y$

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$CeO_{2}/BaTiO_{3}$ 이중완충막을 이용한 YBCO 박막 제작 (Fabrication of YBCO superconducting film with $CeO_{2}/BaTiO_{3}$double buffer layer)

  • 김성민;이상렬
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 하계학술대회 논문집
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    • pp.790-793
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    • 2000

  • We have fabricated good quality superconducting YBa$_2$Cu$_3$$O_{7-x}$(YBCO) thin films on Hastelloy(Ni-Cr-Mo alloys) metallic substrates with CeO$_2$and BaTiO$_3$buffer layers in-situ by pulsed laser deposition in a multi-target processing chamber. YBCO film with CeO$_2$ single buffer layer shows T$_{c}$ of 71.64 K and the grain size less than 0.1 ${\mu}{\textrm}{m}$. When BaTiO$_3$is used as a single buffer layer, the grain size of YBCO is observed to be larger than that of YBCO/CeO$_2$by 200 times and the transition temperature of the film is enhanced to be about 84 K. CeO$_2$/BaTiO$_3$double buffer layer has been adopted to enhance the superconducting properties, which results in the enhancement of the critical temperature and the critical current density to be about 85 K and 8.4 $\times$ 10$^4$ A/cm$^2$ at 77 K, respectively mainly due to the enlargement of the grain size of YBCO film.ilm.

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용융온도와 유지시간이 용융법으로 제작한 고온초전도체의 임계특성에 미치는 영향 (The Effects of Melting Temperature and Holding Time on Critical Characteristics of HTSC Fabricated by Melting Method)

  • 임성훈;한태희;박경국;임성우;조동언;한병성
    • 한국전기전자재료학회논문지
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    • 제11권2호
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    • pp.154-161
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    • 1998

  • The effects of melting temperature and holding time on the critical current density($J_c$) of $YBa_2Cu_3O_x$ based superconducting bulk fabricated by MPMG process were investigated. The amount of the formed $Y_2BaCuO_5$ phases increased with the melting temperature. However, the value of critical current density was highest at 1120 $^{\circ}C$. With this proper melting temperature, the effect of holding time on the critical characteristics was also investigated. In the case of Ag addition, the volume of the formed $Y_2BaCuO_5$ phase when the amount of Ag addition was 10 wt% and 20 wt% was observed to be highest at 20 minute and 40 minute respectively. But in the specimen without Ag, volume of $Y_2BaCuO_5$ phase increased as the holding time increased. The proper melting temperature and the holding time obtained were 1120 $^{\circ}C$ and 20 minute. The long holding time was not effective for the $J_c$ improvement as well as the formation of $Y_2BaCuO_5$.

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위성방송 수신용 원형 편파 고온초전도 평판 배열 안테나 (Design of the High-Temperature Superconducting Patch Array Antenna with Circular Polarization for DBS Receiver)

  • 하재권;강광용;곽민환
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2001년도 학술대회 논문집
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    • pp.142-144
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    • 2001

  • We designed superconducting four-element patch array antenna which has single-feed circularly polarization and a resonance frequency of 11.85 GHz for DBS receiving system. Antennas have been fabricated from both gold conductor and $YBa_{2}$$Cu_{3}$$O_{7-x}$(YBCO) superconductor (thin films) for comparison. Simulated and measured results, and analysis on resonant frequency(fr), return loss, and bandwidth are presented.

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레이저 증착법을 이용한 금속기판상 고온초전도 박막증착 및 특성분석 (Fabrication and Characterization of High Temperature Superconducting Thin Film on Metallic Substrate Using Laser Ablation)

  • 이상렬
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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    • pp.329-331
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    • 1995

  • Laser ablation was used to fabricate superconducting $YBa_2Cu_3O_{7-x}$ (YBCO) thin films on metallic substrates with an YSZ buffer layer. An ArF excimer laser with an wavelength of 193 nm was used to deposit both YSZ buffer layer and superconducting thin film. The characterizations of thin films were performed and compared. With a 200 nm YSZ buffer layer, c-axis orientation and $T_c$=85 K were obtained for a 200 nm-thick YBCO film.

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