Critical Current Density of the AG-Clad BI-Based Superconductors

1992 ◽  
Vol 275 ◽  
Author(s):  
S. X. Dou ◽  
Y. C. Guo ◽  
H. K. Liu

ABSTRACTA high-Tc phase formation-decomposition-recovery process(PFDR) through the use of a short period of melting has been developed for fabrication of Ag-clad Bi-Pb-Sr-Ca-Cu-O (BPSCCO) wires. The weak links and flux pinning have been significantly improved and an extended plateau regime in the Jc-H curve has been observed. The PFDR processed tapes exhibit 3 to 10-fold increase in the Jc at 77 K and 1 Tesla over the normally processed tapes. A Jc of 40000 A/cm2 at 77 K and 0 T and 9000 A/cm2 at 77 K and 1 T have been achieved. The Jc correlates well with the degree of grain alignment which can be measured through the Jc dependence on the orientation of the applied field. The improved Jc - H characteristics is attributed to the desirable microstructures consisting of well aligned (Bi,Pb)2Sr2Ca2Cu3O10+y (2223) grains, fraction of (Bi,Pb)2Sr2CaCu2O8+y(2212) and high density of dislocations produced through PFDR process. The superconducting Ag/Bi-Pb-Sr-Ca-Cu-O wires can be made flexible. The Jc remains unchanged when wires of superconductor thickness 25 μm are bent to a strain rate of 1.5%

2011 ◽  
Vol 324 ◽  
pp. 241-244 ◽  
Author(s):  
R. Mawassi ◽  
R. Awad ◽  
Mohamad Roumie ◽  
M. Kork ◽  
I. Hassan

The major limitation of Bi-system superconductor applications is the intergrain weak links and weak flux pinning capability producing low critical current density of the Bibased phases. In order to enhance these characteristics and other superconducting properties, effective flux pinning centers are introduced into high temperature superconductors. In this work, different weight percentages of ZnO nano oxide were introduced at the final stage of the Bi1.8Pb0.4Sr2Ca2Cu3O10-y superconductor preparation process. Phase characterization was completed by X-ray diffraction (XRD). Exact constitution of the samples was determined using particle induced X-ray emission (PIXE). Granular and microstructure were investigated using scanning electron microscopy (SEM). Electrical resistivity as function of the temperature was carried to evaluate the relative performance of samples, and finally, E-J characteristic curves were obtained at 77K. Using 0.4 ZnO weight percentage, the electrical and granular properties were greatly enhanced, indicating more efficient pinning mechanisms. A critical current density of 949 A/cm2 was obtained which represents more than twice the value obtained for the pure sample (Jc= 445 A/cm2).


1995 ◽  
Vol 250 (1-2) ◽  
pp. 55-58 ◽  
Author(s):  
R.L. Wang ◽  
H.C. Li ◽  
B. Yin ◽  
J.W. Li ◽  
X.S. Ron ◽  
...  

2006 ◽  
Vol 74 (17) ◽  
Author(s):  
J. Chen ◽  
V. Ferrando ◽  
P. Orgiani ◽  
A. V. Pogrebnyakov ◽  
R. H. T. Wilke ◽  
...  

1993 ◽  
Vol 07 (01n03) ◽  
pp. 157-161 ◽  
Author(s):  
D. SURESH BABU ◽  
G. NARSING RAO ◽  
L. BROHAN ◽  
M. GANNE

We report on the ac susceptibility, microwave absorption and dc magnetization of Bi 2− x V x Sr 2 Ca 2 Cu 3 O y (nominal composition). The low T c (2212) phase ( T c = 85 K ) dominates in the x = 0 sample with extremly weak flux pinning. In x = 0.4 sample, both flux pinning and volume fraction of the high T c (2223) phase ( T c = 105 K ) were increased. The intragrain critical current density of the sample with x = 0.4 was estimated and found to be comparable with that of Pb doped Bi 2 Sr 2 Ca 2 Cu 3 O y superconductor. The data suggest that addition of V 2 O 5 in Bi 2 Sr 2 Ca 2 Cu 3 O y system increases the volume fraction of the high T c phase. Probable role of vanadium in enhancing the high T c (2223) phase in Bi-V-Sr-Ca-Cu-O system is discussed.


2018 ◽  
Vol 2 (4) ◽  
pp. 045015 ◽  
Author(s):  
Dinesh Kumar ◽  
Shibnath Samanta ◽  
K Sethupathi ◽  
M S Ramachandra Rao

Author(s):  
Yongqiang Pan ◽  
Nan Zhou ◽  
Bencheng Lin ◽  
Jinhua Wang ◽  
Zengwei Zhu ◽  
...  

Abstract Fe1+yTe0.6Se0.4 has considerable application potential due to its large critical current density (J c) and high upper critical magnetic field (H c2). However, the uncertainty of the anisotropy of J c and the unclear flux-pinning mechanism have limited the application of this material. In this study, the J c in three directions were obtained from magnetic hysteresis loop measurements. A large anisotropy of J c ab /J c c ~ 10 was observed, and the origin of the anisotropy was discussed in details. Flux pinning force densities (F p) were obtained from J c, and a non-scaling behavior was found in the normalized pinning force f p[F p/F p-max] versus the normalized field h[H/H c2]. The peaks of pinning force shift from a high h to a low h with increasing temperature. Based on the vortex dynamics analysis, the peak shift was found to originate from the magnetization relaxation. The J c and F p at critical states free from the magnetic relaxation were regained. According to the Dew-Hughes model, the dominant pinning type in Fe1+yTe0.6Se0.4 clean single crystals was confirmed to be normal point pinning.


2021 ◽  
Vol 21 (9) ◽  
pp. 4941-4943
Author(s):  
Sang Heon Lee

In the present study, a YBa2Cu3O7−y bulk superconductor added with 5~10 wt% Ag was fabricated employing Sm123 as a seed to produce a superconductive single crystal. Metallic silver was added to the single crystal of YBa2Cu3O7−y to remove defects such as cracks and pores. Electromagnetic properties of the bulk superconductor at 77 K were analyzed based on relationships of magnetic levitation, trapped magnetic force, and critical current density. The critical current density of the superconductor at 77 K and 0 T was 3.53 × 104 A/cm2. Discontinuous points in the distribution of magnetic field lines were not observed, implying that these two specimens grew well as a single crystal without specific weak links. For the growth of a superconductive nano crystal employing slow cooling at temperature of formation of 123 phase, superconductive nano crystals were aligned in a-b direction, the direction of peak current flow. The peak value of the trapped magnetic force of the YBa2Cu3O7−y superconductor specimen was 3.23 kG. Using the FC method, peak forces of attraction and repulsion were 21.696 N and 70.168 N, respectively.


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