• 제목/요약/키워드: critical current density

검색결과 587건 처리시간 0.037초

전착 첨가물에 의한 전기영동 초전도 YBCO 후막선재의 임계전류밀도 개선 (Critical Current Density Improvement of Superconducting YBCO Thick Film by using EPD Additives)

  • 소대화;임병재;전용우;박정철;최성재
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
    • /
    • pp.123-126
    • /
    • 2003
  • The electrophoretic deposition method using the suspension solution with additives under the electric potential was applied for the fabrication of YBCO superconductor wire. This method was able to simplify the fabrication facilities, and produce an uniform and dense thick film. To improve the critical current density of deposited films, the additive PEGs(Poly Ethylene Glycole) with the molecular weight of 600, 1000 and 3400, were used as chemical binders for the suspension solution. The organic additive PEG showed better effects to the properties of YBCO superconductor wire. The PEG improved the adhesion between superconductor particles and suppressed the crack on the surface, which enhanced the surface uniformity and density of YBCO deposited film. It was found that acetone suspension solution showed better deposition properties than the others. The samples fabricated in the solution with the additive, 8 vol.% of 1% PEG(1000), showed the highest critical current density measured as $2300{\sim}2400\;Acm^2$ at 77 K, 0 T.

  • PDF

기계적 밀링 및 글리세린 처리된 보론 분말을 사용하여 제조된 $MgB_2$의 임계전류밀도 향상 (Enhancement of the Critical Current Density of $MgB_2$ Prepared using Mechanically Milled and Glycerin Treated Boron Powder)

  • 전병혁;김이정;김찬중
    • Progress in Superconductivity
    • /
    • 제10권1호
    • /
    • pp.40-44
    • /
    • 2008
  • A combined process of a mechanical ball milling and liquid glycerin ($C_{3}H_{8}O_3$) treatment of boron (B) powder has been conducted to enhance the superconducting properties of $MgB_2$. The individual aims of the mechanical milling and the glycerin treatment were to reduce the grain size of the $MgB_2$ and to achieve homogeneous carbon (C) incorporation into the $MgB_2$, respectively. Four kinds of B powders of as-received, glycerin treated, 2 h milled, and 2 h milled + glycerin treated were prepared. $MgB_2$ bulks were fabricated by in situ process using the prepared B powders. The mechanical ball milling was effective for a grain refinement, and a lattice disorder was easily achieved by glycerin addition. It was found that the critical current density ($J_c$) values were enhanced in the samples with milled B or glycerin treated B only. In the $MgB_2$ bulk prepared with both milled and glycerin treated B, the $J_c$ was further increased due to a higher grain boundary density and a greater C substitution.

  • PDF

용융성장시 서냉시간과 후열처리시간에 따른 임계특성 (The Critical Characteristics Attributed to the Slow Cooling and Annealing Time in the Melting Growth)

  • 임성훈;최명호;강형곤;정동철;박종광;한병성
    • 한국전기전자재료학회논문지
    • /
    • 제11권4호
    • /
    • pp.327-333
    • /
    • 1998
  • The influence of slow cooling and annealing time in $O_2$in MPEG process on $J_c$ was investigated. From the measurement of $J_c$,SEM and XRD, it was observed that the critical current density was related with the slow cooling time and annealing time in $O_2$. The value of $J_c$ was the highest at slow cooling time of 40 hour. And also, the value of $J_c$ along the annealing time in $O_2$in the case of the slow cooling time of 40 hours was inclined to increase with annealing time. Consequently, it can be suggested that proper slow cooling time and annealing time after slow cooling in MPMG process be important to improve the critical characteristics.

  • PDF

Line-shaped superconducting NbN thin film on a silicon oxide substrate

  • Kim, Jeong-Gyun;Suh, Dongseok;Kang, Haeyong
    • 한국초전도ㆍ저온공학회논문지
    • /
    • 제20권4호
    • /
    • pp.20-25
    • /
    • 2018
  • Niobium nitride (NbN) superconducting thin films with the thickness of 100 and 400 nm have been deposited on the surfaces of silicon oxide/silicon substrates using a sputtering method. Their superconducting properties have been evaluated in terms of the transition temperature, critical magnetic field, and critical current density. In addition, the NbN films were patterned in a line with a width of $10{\mu}m$ by a reactive ion etching (RIE) process for their characterization. This study proves the applicability of the standard complementary metal-oxide-semiconductor (CMOS) process in the fabrication of superconducting thin films without considerable degradation of superconducting properties.