Flux Pinning and Weak Link Structure in Ca2Cu1O3 Doped LnBa2Cu3O7-y (Ln=La and Y)

1989 ◽  
Vol 169 ◽  
Author(s):  
F. Mizuno ◽  
H. Masuda ◽  
I. Hirabayashi ◽  
S. Tanaka
Keyword(s):  
Magnetic Field ◽  
Flux Pinning ◽  
Magnetic Field Dependence ◽  
Weak Link ◽  
Impurity Phase ◽  
Experimental Result ◽  
Ca Doping ◽  
Link Structure ◽  
Pinning Center ◽  
The Magnetic Field

AbstractFlux pinning and weak link structure were studied on the effect of Ca doping in LnBa2Cu3O7-y system (Ln=La and Y). The magnitude and the magnetic field dependence of the critical current density were improved by Ca doping. A small amount of impurity phase of such as Ca2Cu1O3 may work as a desirable flux pinning center. Moreover, it was found that the current-temperature characteristics for Ca-doped samples showed the evidence of two kinds of superconducting phases which have different transition temperature Tc and Tc'. The experimental result agrees well with the Ambegaokar-Baratoff theory for asymmetric Josephson junctions (S-I-S') in the temperature range of T < Tc' and with the proximity junction theory (S-N-S) in the range of Tc'<T<Tc.

MAGNETIC FIELD DEPENDENCE OF CRITICAL CURRENTS IN SUPERCONDUCTING POLYCRYSTALS

1992 ◽  
Vol 06 (03) ◽  
pp. 161-169 ◽  
Author(s):  
K.I. KUGEL ◽  
T. YU. LISOVSKAYA ◽  
R.G. MINTS
Keyword(s):  
Magnetic Field ◽  
Magnetic Field Dependence ◽  
Asymptotic Form ◽  
Critical Currents ◽  
Transport Current ◽  
Wide Field ◽  
London Penetration Depth ◽  
Field Range ◽  
Crystallographic Axes ◽  
The Magnetic Field

We study the dependence of critical current j c on magnetic field H in superconducting polycrystals which are considered as systems of superconducting crystallites (isotropic or anisotropic) with Josephson contacts between them. Isotropy or anisotropy of contacts depends on the orientation of their crystallographic axes relatively to edges of contact planes. It is shown that for a system of randomly oriented isotropic contacts, the dependence j c (H) in a relatively wide field range has the asymptotic form j c ~( ln H)/H2. This differs drastically from j c (H) for single contacts. Anisotropy effects due to large differences in London penetration depth λ values corresponding to external magnetic field directed along different axes are analyzed in detail. It is shown that for uniaxal crystals with λ1=λ2≪λ3, this anisotropy leads to the relation [Formula: see text] for chaotic orientation of crystallites. The form of j c (H) curves for two different orientations of the magnetic field relatively to the transport current through the sample is found.

The magnetic field dependence of the low temperature (0.1K to 3K) residual specific heat of Pr2−x Ce x CuO4−δ

1996 ◽  
Vol 46 (S3) ◽  
pp. 1213-1214 ◽  
Author(s):  
T. E. Hargreaves ◽  
J. Akimitsu ◽  
D. F. Brewer ◽  
N. E. Hussey ◽  
H. Noma ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Specific Heat ◽  
Field Dependence ◽  
Magnetic Field Dependence ◽  
The Magnetic Field

Mechanism of the magnetic field dependence for the liquid phase photoreaction in the nanotube of MCM-41

2002 ◽  
Vol 4 (7) ◽  
pp. 1201-1205 ◽  
Author(s):  
Masaharu Okazaki ◽  
Kazumi Toriyama ◽  
Kiichi Oda ◽  
Toshio Kasai
Keyword(s):  
Magnetic Field ◽  
Liquid Phase ◽  
Field Dependence ◽  
Magnetic Field Dependence ◽  
The Magnetic Field ◽  
Mcm 41
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