In:
Acta Physica Sinica, Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, Vol. 42, No. 10 ( 1993), p. 1669-
Abstract:
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.
Type of Medium:
Online Resource
ISSN:
1000-3290
,
1000-3290
Language:
Unknown
Publisher:
Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
Publication Date:
1993
