Earticle

초록

영어

The effects of MgB4 addition on the superconducting properties and the microstructure of in situ processed MgB2 bulk superconductors were studied. MgB4 powder of 1-20 wt.% was mixed with (Mg + 2B) powder and then pressed into pellets. The pellets of (Mg + 2B + xMgB4) were heat-treated at 650 ℃ for 1 h in flowing argon. The powder X-ray diffraction (XRD) analysis for the heat-treated samples showed that the major formed phase in all samples was MgB2 and the minor phases were MgB4 and MgO. The full width at half maximum (FWHM) values showed that the grain size of MgB2 decreased as the amount of MgB4 addition increased. MgB4 particles included in a MgB2 matrix is considered to suppress the grain growth of MgB2. The onset temperatures (Tc,onset) of MgB2 with MgB4 addition (0-10 wt.%) was between 37-38 K. The 20 wt.% MgB4 addition slightly reduced the Tc,onset of MgB2 to 36.5 K. This result indicates that MgB4 addition did not influence the superconducting transition temperature (Tc) of MgB2 significantly. On the other hand, the small additions of 1-5 wt.% MgB4 increased the critical current density (Jc) of MgB2. The Jc enhancement by MgB4 addition is attributed not only to the grain size refinement but also to the possible flux pinning of MgB4 particles dispersed in a MgB2 matrix.

목차

Abstract
 1. INTRODUCTION
 2. EXPERIMENTAL PROCEDURE
 3. RESULTS AND DISCUSSION
 4. CONCLUSIONS
 ACKNOWLEDGMENTS
 REFERENCES

키워드

저자

• S. H. Kim [ Korea Atomic Energy Research Institute, Sungkyunkwan University, Suwon, Korea ]
• W. N. Kang [ Sungkyunkwan University, Suwon, Korea ]
• B.-H. Jun [ Korea Atomic Energy Research Institute, Daejeon, Korea ]
• Y. J. Lee [ Korea Atomic Energy Research Institute, Sungkyunkwan University, Suwon, Korea ]
• C.-J. Kim [ Korea Atomic Energy Research Institute, Daejeon, Korea ] Corresponding author

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  한국초전도·저온논문지 (구 한국초전도저온공학회논문지) [Progress in Superconductivity and Cryogenics]

• 간기

  계간

• pISSN

  1229-3008

• eISSN

  2287-6251

• 수록기간

  1999~2025

• 등재여부

  KCI 등재,SCOPUS

• 십진분류

  KDC 427 DDC 537