• Title/Summary/Keyword: Bi-2201

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BSCCO 박막의 부착계수 해석 (Analysis of Sticking Coefficient in BSCCO Thin Film)

  • 천민우;박용필
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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    • pp.252-255
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    • 2002
  • BSCCO thin films are fabricated by an ion beam sputtering method, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element in BSCCO film formation was observed to show a unique temperature dependence; it was almost a constant value of 0.49 below about $730^{\circ}C$ and decreased linearly over about $730^{\circ}C$. In contrast, Sr and Ca, displayed no such remarkable temperature dependence. This behavior of the sticking coefficient was explained consistently on the basis of the evaporation and sublimation processes of $Bi_{2}O_{3}$. It was concluded that Bi(2212) thin film constructs from the partial melted Bi(2201) phase with the aid of the liquid phase of $Bi_{2}O_{3}$.

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스퍼터 증착법으로 제작한 Bi-Sr-Ca-Cu-O 고온 초전도 박막 (High-Tc Superconducting Bi-Sr-Ca-Cu-O Thin Films prepared by Sputter Deposition)

  • 천민우;양승호;박노봉;박용필
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.329-330
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    • 2005
  • Bi-Sr-Ca-Cu-O thin films have been fabricated by sputter deposition method. During the deposition, 10 and 90 wt%-ozone/oxygen mixture gas of typical pressure of $1\sim9\times10^{-5}$ Torr are supplied with ultraviolet light irradiation for oxidation. XRD and RHEED investigations reveal out that a buffer layer with some different compositions 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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BSCCO 박막의 저항-온도 특성 (R-T Characteristic in BSCCO Thin Films)

  • 천민우;양승호;박용필
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 춘계학술대회 논문집
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    • pp.98-101
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    • 2005
  • BSCCO thin films fabricated by using the evaporation method. As a result, although the composition of Bi2212 was set up, the phase of Bi2201, Bi2212 and Bi2223 was formed. The formation area of these stable phases is indicated as inclined line in the direction of the right lower end from the Arrhenius plot of the substrate temperature-oxidation gas pressure, and are distributed in very small area. The activation energy for the phase transformation from the Bi2201 to the Bi2212 is estimated in terms of the Avrami equation.

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부착율 개선을 위해 증발 법으로 제작한 Bi2Sr2CanCun+1Ox 박막의 부착 특성 (Sticking Characteristics in Bi2Sr2CanCun+1Ox Thin Films Fabricated by using the Evaporation Method to Improve the Sticking Ratio)

  • 천민우;박용필
    • 한국전기전자재료학회논문지
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    • 제16권11호
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    • pp.1029-1034
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    • 2003
  • The Bi$_2$Sr$_2$Ca$_{n}$Cu$_{n+1}$ O$_{x}$, superconducting thin films arc fabricated by using the sputtering and evaporation method. Because we confirmed the sticking ratio of Bi element in the Bi$_2$Sr$_2$Ca$_{n}$Cu$_{n+1}$ O$_{x}$ superconducting thin film fabricated by using the sputtering method was much lower than the expected value, to get the enough number of the flakes of Bi, faraday cup was used to evaporate Bi clement. As a result of the fabrication, Bi 2201 and Bi 2212 single phases could be made by the optima of deposition condition. And we confirmed the sticking coefficient of Bi element was clearly related to the temperature change of the substrate and the generation of Bi22l2 phase

Phase Stability and Electronic Properties of $Bi_2BaLnCuO_{6+δ}$ Cuprates with Structure 2201 Type

  • V. E. Fedorov;N. G. Naumov;P. P. Samoilov;N. F. Zakharchuk;N. I. Matskevich;백우현
    • Bulletin of the Korean Chemical Society
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    • 제16권6호
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    • pp.484-489
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    • 1995
  • The synthesis of new bismuth-barium containing members of layered cuprates with 2201 type structure was reported. By solution calorimetry the formation enthalpies for Bi2MLaCuO6.5 (M=Ba, Ba0.5Sr0.5, Sr) were obtained. Crucial influence of partial oxygen pressure and size of lanthanoid on stability of layered cuprates was shown. Electronic states of variable valence atoms were studied by voltammetry of solids.

Epitaxial Growth of BSCCO Type Structure in Atomic Layer by Layer Deposition

  • Yang, Sung-Ho;Park, Yong-Pil;Jang, Kyung-Uk;Oh, Geum-Gon;Lee, Joon-Ung
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2000년도 추계학술대회논문집
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    • pp.97-100
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    • 2000
  • Si$_2$Sr$_2$CuO$\sub$x/(Bi(2201)) thin films are fabricated by atomic layer by layer deposition using ion beam sputtering(IBS) method. During the deposition, 10 %-ozone/oxygen mixture gas of typical 5.0 ${\times}$ 10$\^$-5/ Torr is applied with ultraviolet light irradiation for oxidation. XRD and RHEED investigations reveal out that a buffer layer with some different compositions is formed at the early deposition stage of less than 10 units cell and then c-axis oriented Bi(2201) is grown.

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이온 빔 스퍼링 법으로 제작한 Bismuth계 초전도 박막의 저항률-온도특성에 관한 연구 (A Study on the Resistivity-Temperature Characteristic of the Bi-Superconducting Thin Films Fabricated by using the Bon Beam Sputtering Method)

  • 천민우;박노봉;양승호;박용필
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.1218-1221
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    • 2004
  • Bi2212 superconducting thin films fabricated by using the ion Beam Sputtering Method. As a result, although the composition of Bi2212 was set up, the phase of Bi2201, Bi2212 and Bi2223 was formed. The formation area of these stable phases is indicated as inclined line in the direction of the right lower end from the Arrhenius plot of the substrate temperature-oxidation gas pressure, and are distributed in very small area. The activation energy for the phase transformation from the Bi2201 to the Bi2212 is estimated in terms of the Avrami equation.

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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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    • 제2권1호
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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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i-beam 스퍼터링 법으로 제작한 BiSrCaCuO 박막의 열역학분석 (Analysis of Thermodynamics in BiSrCaCuO Thin Films Fabricated by Using the i-beam sputtering method)

  • 김태곤;박용필
    • 한국정보통신학회논문지
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    • 제11권1호
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    • pp.89-94
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    • 2007
  • 다양한 기판 온도와 산화 가스 압력 하에서 i-beam 스퍼터링 법으로 BiSrCaCuO 박막을 제작하였다. 기판온도 $T_{sub}$와 산화 가스 압력 $pO_3$를 변화시키며 제작된 Bi2212 및 Bi2223 박막의 생성상도를 작성하였다. Bi2212 조성으로 스퍼터링 하였으나 Bi2212 상 뿐 아니라 Bi2201 상과 Bi2223 상이 모두 생성되었고, Bi2212나 Bi2223 단상은 매우 좁은 온도 영역에서만 형성되었다. 생성 엔탈피의 변화 ${\Delta}{\bar}HO_2$와 생성 엔트로피의 변화 ${\Delta}{\bar}SO_2$에 대한 열역학적인 계산을 통해 Bi2212 단상이 형성된 경우 각각 -260 kJ/mol 및 $-225J/mol{\cdot}K$의 값을 얻었다.

$Bi_2Sr_2Ca_1Cu_2O_x$ 조성으로 제작된 박막의 결정상에 대한 고용비 해석 (Analysis of the Staking Fault in Crystalline Phase of Thin Films Fabricated by $Bi_2Sr_2Ca_1Cu_2O_x$ Composition)

  • 양승호;이호식;박용필
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2007년도 춘계종합학술대회
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    • pp.524-527
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    • 2007
  • 이온 빔 스퍼터법을 이용하여 저속성장으로 동시 증착에 의해 $Bi_2Sr_2Ca_{n-1}Cu_nO_x$(n=0, 1, 2) 박막을 제작하였다. Bi 2212 상은 기판온도 $750\sim795^{\circ}C$의 범위에서 나타났으며, $750^{\circ}C$보다 저온 측에서는 Bi 2201의 단일강이 존재하였나. 그러나, 조성과 관계되는 $PO_3$에 대해서 크게 변하지 않았다. 그리고 임계온도(Tc)가 $45\sim90K$ 가지는 c축 배향한 고품질의 Bi 2212 박막을 얻었다. 소수의 박막에서는 소량의 CuO가 불순물로 관찰되었으며, 얻어진 모든 박막에서 $CaCuO_2$의 불순물 상은 관찰되지 않았다.

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