• 제목/요약/키워드: Pinning center

검색결과 79건 처리시간 0.02초

Synthesis of high quality infinite-layer superconducting compound of Sr$_{0.9}$Sm$_{0.1}$CuO$2$ and its pinning properties

  • Park, Min-Seok;Kim, J.Y.;Kim, Mun-Seog;Kim, Heon-Jung;Lee, Sung-Ik;Jung, C.U.
    • 한국초전도학회:학술대회논문집
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    • 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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    • pp.125-127
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    • 2000
  • We report high pressure synthesis of Sr$_{0.9}$Sm$_{0.1}$CuO$_2$. Powder x-ray diffraction showed that the synthesized compounds have infinite layer structure as a major component. Slow heating at the first stage of heating processes after pressurization resulted in several larger grains. The largest grain was found to have the longest edge length of about 100 micrometer. Through magnetic property measurement in superconducting state, we found that pinning in this compound has substantial difference from that of La doped infinite layer, which has no unpaired spin at Sr site.

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Nanoparticle Deposition for Pinning Centers

  • Lee, Sang-Moo;Yoo, Ja-Eun;Jung, Ye-Hyun;Lee, Jae-Young;Youm, Do-Jun
    • 한국초전도학회:학술대회논문집
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    • 한국초전도학회 2007년도 High Temperature Superconductivity Vol.XVII
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    • pp.38-38
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    • 2007
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Technical Investigation into the In-situ Electron Backscatter Diffraction Analysis for the Recrystallization Study on Extra Low Carbon Steels

  • Kim, Ju-Heon;Kim, Dong-Ik;Kim, Jong Seok;Choi, Shi-Hoon;Yi, Kyung-Woo;Oh, Kyu Hwan
    • Applied Microscopy
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    • 제43권2호
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    • pp.88-97
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    • 2013
  • Technical investigation to figure out the problems arising during in-situ heating electron backscatter diffraction (EBSD) analysis inside scanning electron microscopy (SEM) was carried out. EBSD patterns were successfully acquired up to $830^{\circ}C$ without degradation of EBSD pattern quality in steels. Several technical problems such as image drift and surface microstructure pinning were taking place during in-situ experiments. Image drift problem was successfully prevented in constant current supplying mode. It was revealed that the surface pinning problem was resulted from the $TiO_2$ oxide particle formation during heating inside SEM chamber. Surface pinning phenomenon was fairly reduced by additional platinum and carbon multi-layer coating before in-situ heating experiment, furthermore was perfectly prevented by improvement of vacuum level of SEM chamber via leakage control. Plane view in-situ observation provides better understanding on the overall feature of recrystallization phenomena and cross sectional in-situ observation provides clearer understanding on the recrystallization mechanism.

Bi계 초전도제의 자기부양효과 (Magnetic Suspension Effect of BiPbSrCaCuO Superconductor)

  • 이상헌
    • 한국전기전자재료학회논문지
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    • 제15권6호
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    • pp.535-538
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    • 2002
  • Suspension effect has been studied by using superconductor of BiPbSrCaCuO ceramics containing $Ag_2()$. It has been clear that $Ag_2()$ acts as pinning center which plays an important role to the suspension effect. Magnetic repulsive force which affects a superconductor located in magnetic flux from toroidal magnet, has been investigated. It has been concluded that the suspension effect arises from the interaction between the pinning effect and the diamagnetic effect.

산화물 초전도체의 자기효과 (Magnetic Suspension Effect of Oxide Superconductor)

  • 이상헌;이성갑;이영희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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    • pp.199-202
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    • 2004
  • Suspension effect has been studied by using superconductor of BiPbSrCaCuO ceramics containing $Ag_2O$. It has been c1eared that $Ag_2O$ acts as pinning center which plays an important role to the suspension effect. Magnetic repulsive force which affects a superconductor located in magnetic flux from toroidal magnet has been investigated. It has been concluded that the suspension effect arises from the interaction between the pinning effect and the diamagnetic effect.

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Bi계 초전도체의 Magnetic Suspension (Magnetic Suspension Effect of BiPbSrCaCuO Superconductor)

  • 이상헌
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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    • pp.101-103
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    • 2001
  • Suspension effect has been studied by using superconductor of BiPbSrCaCuO ceramics containing $Ag_{2}O$ It has been cleared that $Ag_{2}O$ acts as pinning center which plays an important role to the suspension effect. Magnetic repulsive force which affects a superconductor located in magnetic flux from toroidal magnet has been investigated. It has been concluded that the suspension effect arises from the interaction between the pinning effect and the diamagnetic effect.

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BSCCO계 초전도체에서 서냉 열처리에 의한 2차상 석출 (The Precipitation of Second Phases by Annealing Heat Treatment in the $(Bi,Pb)_2$${Sr_2}{Ca_2}{Cu_3}{O_{10}}$ Superconductor System)

  • 이상희;김철진;유재무
    • 한국세라믹학회지
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    • 제37권12호
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    • pp.1212-1220
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    • 2000
  • Bi-2223 초전도체계에서 석출물을 flux-pinning center로 이용할 수 있는지 가능성을 타진하기 위하여 $Bi_{1.8}$P $b_{0.4}$S $r_{2}$C $a_{2.2}$C $u_3$ $O_{8}$ 조성을 가진 Bi-2223/Ag 선재를 반응온도, 산소분압, 시간 등을 변화시키면서 열처리를 행하였다. 열처리 후 석출물들은 XRD, SEM, TEM, EDS로 분석하였다. Bi-2223 모상내의 (Ca, Sr)$_2$(Pb,Bi) $O_4$, B $i_{0.5}$ P $b_3$S $r_2$C $a_2$Cu $O_{12+}$$\delta$/ (3221)와 같은 2차상들의 크기와 분포는 2223 입자들의 연결성을 파괴하지 않고 열처리 조건에 의해서 조절할 수 있었다. 서냉 열처리가 된 시편은 임계전류밀도( $J_{c}$)값이 증가하였는데, 이는 2223 입자내 나노미터 크기로 형성된 석출물들이 flux-pinning sites로 작용한 것으로 추정된다.다.

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BiPbSrCaCuO 초전도체의 Fishing 효과 (Fishing Effect of BiPbSrCaCuO Superconductor)

  • 이상헌
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 방전 플라즈마 유기절연재료 초전도 자성체연구회
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    • pp.177-179
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    • 2004
  • Suspension effect has been studied by using superconductor of BiPbSrCaCuO ceramics containing $Ag_2O$. It has been cleared that $Ag_2O$ acts as pinning center which plays an important role to the suspension effect. Magnetic repulsive force which affects a superconductor located in magnetic flux from toroidal magnet has been investigated. It has been concluded that the suspension effect arises from the interaction between the pinning effect and the diamagnetic effect.

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