Earticle

초록

영어

Cryogenic milling which is a combined process of low-temperature treatment and mechanical milling was applied to fabricate high critical current density (Jc)MgB2 bulk superconductors. Liquid nitrogen was used as a coolant, and no solvent or lubricant was used. Spherical Mg (6-12 μm, 99.9 % purity) and plate-like B powder (~ 1 μm, 97 % purity) were milled simultaneously for various time periods (0, 2, 4, 6 h) at a rotating speed of 500 rpm using ZrO2 balls. The (Mg+2B) powders milled were pressed into pellets and heat-treated at 700°C for 1 h in flowing argon. The use of cryomilled powders as raw materials promoted the formation reaction of superconducting MgB2, reduced the grain size of MgB2, and suppressed the formation of impurity MgO. The superconducting critical temperature (Tc) of MgB2 was not influenced as the milling time (t) increased up to 6 h. Meanwhile, the critical current density (Jc) of MgB2 increased significantly when t increased to 4 h. When t increased further to 6 h, however, Jc decreased. The Jc enhancement of MgB2 by cryogenic milling is attributed to the formation of the fine grain MgB2 and a suppression of the MgO formation.

목차

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

키워드

저자

• D. N. Kim [ Korea University of Technology and Education, Korea Atomic Energy Research Institute, Daejeon, Korea ]
• M. O. Kang [ Korea University of Technology and Education, Korea Atomic Energy Research Institute, Daejeon, Korea ]
• B.-H. Jun [ Korea Atomic Energy Research Institute, Daejeon, Korea ]
• C-J. Kim [ Korea Atomic Energy Research Institute, Daejeon, Korea ] Corresponding author
• H. W. Park [ Korea University of Technology and Education, Cheon-an, 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

  1999~2026

• 등재여부

  KCI 등재,SCOPUS

• 십진분류

  KDC 427 DDC 537