WEAK QUANTUM FLUX CREEP AND STRONG PINNING IN THE NEW SUPERCONDUCTOR MgB2

doi:10.1088/1009-1963/10/4/316

中国物理B ›› 2001, Vol. 10 ›› Issue (4): 340-342.doi: 10.1088/1009-1963/10/4/316

WEAK QUANTUM FLUX CREEP AND STRONG PINNING IN THE NEW SUPERCONDUCTOR MgB₂

赵志文, 闻海虎, 李世亮, 倪泳明, 任治安, 车广灿, 杨海朋, 刘志勇, 赵忠贤

National Laboratory for Superconductivity, Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China

收稿日期:2001-03-02 出版日期:2001-04-15 发布日期:2005-07-11
基金资助:
Project supported by the National Natural Science Foundation of China (Grant No. NSFC 19825111) and the Ministry of Science and Technology of China (Grant No. NKBRSF-G1999064602).

WEAK QUANTUM FLUX CREEP AND STRONG PINNING IN THE NEW SUPERCONDUCTOR MgB₂

National Laboratory for Superconductivity, Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China

Received:2001-03-02 Online:2001-04-15 Published:2005-07-11
Supported by:
Project supported by the National Natural Science Foundation of China (Grant No. NSFC 19825111) and the Ministry of Science and Technology of China (Grant No. NKBRSF-G1999064602).

摘要/Abstract

摘要： The newly discovered superconductor MgB₂ has a transition temperature T_c of about 40 K, which is touching the upper line of that predicted by the phonon-mediated Bardeen--Cooper--Schrieffer (BCS) theory. It is interesting to investigate the flux creep in MgB₂ and compare it with other superconductors. We have measured the magnetization relaxation of MgB₂ sintered at high temperature and high pressure. It is found that the quantum tunnelling and the thermally activated flux creep are very weak, implying a strong pinning in this material.

Abstract: The newly discovered superconductor MgB₂ has a transition temperature T_c of about 40 K, which is touching the upper line of that predicted by the phonon-mediated Bardeen--Cooper--Schrieffer (BCS) theory. It is interesting to investigate the flux creep in MgB₂ and compare it with other superconductors. We have measured the magnetization relaxation of MgB₂ sintered at high temperature and high pressure. It is found that the quantum tunnelling and the thermally activated flux creep are very weak, implying a strong pinning in this material.

Key words: MgB₂, flux creep, pinning

中图分类号: (Metals; alloys and binary compounds)

74.70.Ad

74.10.+v (Occurrence, potential candidates) 74.25.Kc (Phonons) 74.20.Fg (BCS theory and its development) 74.25.Ha (Magnetic properties including vortex structures and related phenomena)

赵志文, 闻海虎, 李世亮, 倪泳明, 任治安, 车广灿, 杨海朋, 刘志勇, 赵忠贤. WEAK QUANTUM FLUX CREEP AND STRONG PINNING IN THE NEW SUPERCONDUCTOR MgB₂[J]. 中国物理B, 2001, 10(4): 340-342.

Zhao Zhi-wen (赵志文), Wen Hai-hu (闻海虎), Li Shi-liang (李世亮), Ni Yong-ming (倪泳明), Ren Zhi-an (任治安), Che Guang-can (车广灿), Yang Hai-peng (杨海朋), Liu Zhi-yong (刘志勇), Zhao Zhong-xian (赵忠贤). WEAK QUANTUM FLUX CREEP AND STRONG PINNING IN THE NEW SUPERCONDUCTOR MgB₂[J]. Chinese Physics, 2001, 10(4): 340-342.

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WEAK QUANTUM FLUX CREEP AND STRONG PINNING IN THE NEW SUPERCONDUCTOR MgB₂

WEAK QUANTUM FLUX CREEP AND STRONG PINNING IN THE NEW SUPERCONDUCTOR MgB₂

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