Earticle

초록

영어

Using a SQUID-VSM magnetometer, we measured the magnetic moment as functions of applied magnetic field and temperature, denoted m(H) and m(T), respectively, for untreated MgB2 powder and MgB2 powders heat-treated in an Ar atmosphere. To quantify the symmetry and asymmetry of the magnetic hysteresis loops, we decomposed the m(H) data into symmetric and asymmetric components, denoted by |Δm(H)| and |Σ(H)|, respectively, and attributed these components to bulk pinning and surface barriers. For all samples investigated, the magnitude of the symmetric component was approximately two to three times that of the asymmetric component. The degree of asymmetry was further quantified using an asymmetry index, η(H) = |Σ(H)| / |Δm(H)|. In addition, the critical current density, Jc ∞ ΔM, can be estimated for each sample using the conventional Bean critical-state model. The variation in the irreversible magnetization ΔM with heat-treatment temperature, Tan, was examined in relation to changes in the asymmetry index. In particular, the increase in ΔM at Tan = 800 °C relative to that at 750 °C coincided with a pronounced decrease in the asymmetry index. This decrease was accompanied by an increase in the ΔM value, which may be related to the higher Jc value estimated by the Bean model.

목차

Abstract
1. INTRODUCTION
2. EXPERIMENTAL PROCEDURE
3. RESULTS AND DISCUSSION
4. SUMMARY
ACKNOWLEDGMENT
REFERENCES

키워드

저자

• Ho Cheol Hwang [ Division of Science Education and Institute of Fusion Science, Jeonbuk National University, Jeonju 54896, Republic of Korea ]
• Kyu Jeong Song [ Division of Science Education and Institute of Fusion Science, Jeonbuk National University, Jeonju 54896, Republic of 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