Open AccessFLUX PINNING EFFECT OF OXYGEN DEFICIENCIES IN YBa2Cu3Oy
Author(s) -
Hu Gang-Jin,
Fang Minghu,
Zhongxian Li,
Zeng Xing-Bin,
Chen Nan-Song,
Jiao Zhen-Kuan,
Qirui Zhang,
Yitong Zhang,
Xin Jin,
X.X. Yao
Publication year - 1993
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.42.1669
Subject(s) - condensed matter physics , flux pinning , magnetization , pinning force , flux (metallurgy) , critical current , oxygen , magnetic flux , materials science , scaling , magnetic field , field (mathematics) , scaling law , phase (matter) , physics , superconductivity , quantum mechanics , geometry , mathematics , metallurgy , pure mathematics
A series of single phase YBa2Cu3Oy samples with various oxygen contents and Tcmid's> 90K were prepared, and their structures, superconductivities, flux pinning behaviors have been determined and investigated. The experimental results show that the oxygen deficiencies result in enhancements of critical current density Jc and flux pinning force density Fp, moreover, there exists an optimal concentration of okygen deficiencies, corresponding to the maximal enhancemenes of Jc and Fp. Different from the cases of y= 6. 96,6. 83,Jc of y= 6.94,6.86 samples vary unmonotonicly with magnetic field H, correpondingly, the magnetization curves exhibit an abnormal peak known as "fishtail" effect. Fitted with the scaling law, it is found that when 6.83≤y≤6.94, the peak in fp(h) curves appears at the same reduced magnetic field h(≈0. 6). It indicates that the existence of oxygen deficiencies introduces new flux pinning centres in YBa2Cu3Oy.