Journal of the Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회논문지)

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
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Phase Transformation and Misconstruct of REBa2Cu3O7-x (RE=Nd, Gd, Dy) Superconductor during Heat treatment

REBa2Cu3O7-x (RE=Nd, Gd, Dy) 초전도체의 열처리에 따른 상변태와 미세구조

  • 오용택 (조선대학교 에너지자원신기술연구소) ;
  • 한용희 (한국전력공사 인천지사) ;
  • 한병성 (전북대학교 전자정보공학부) ;
  • 한상철 (한전전력연구원 신에너지 그룹) ;
  • 성태현 (한전전력연구원 신에너지 그룹) ;
  • 홍광준 (조선대학교 물리화학부) ;
  • 신동찬 (조선대학교 신소재공학과)
  • Published : 2003.12.01
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Abstract

This study investigated the phase transformation of the REBa$_2$Cu$_3$$O_{7-x}$ (RE=Nd, Gd, Dy) superconductor, and CCT (Continuous-Cooling-Transformation) along with the TTT (Time-Temperature-Transformation) diagrams are suggested according to the isothermal and continuous cooling heat-treatments. The peritectic temperature of the 123 phases decreased approximately 3$0^{\circ}C$ when the ionic radius of the rare-earth elements was reduced. The optimum cooling rate where BC and Cu-free phases do not exist was 0.001$^{\circ}C$/s. At this cooling late, the 123 phase grew with a c-axis Perpendicular to the surface and had a well-distributed 211 phase. When the oxygen partial pressure was reduced Outing isothermal heat-treatment, the formation temperature of the 211 phase decreased. In addition, the formation temperature of the 123 phases decreased from 100$0^{\circ}C$ (Nd-123) to 9$25^{\circ}C$ (Gd-123), and finally 875$^{\circ}C$ (Dy-123) according to the decrease in the ionic radius of the tare-earth elements. Compared to Nd-123, Gd- and Dy-123 had a better texture with a well-distributed 211 phase.e.

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References

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