scholarly journals Temperature Dependence of the Zero-Field In-Plane Critical Current Density of YBa2Cu3O7-d High-Tc Superconductors

2012 ◽  
Vol 4 (2) ◽  
pp. 287 ◽  
Author(s):  
M. R. H. Sarkar ◽  
S. H. Naqib
Keyword(s):  
Critical Current Density ◽  
Temperature Dependence ◽  
Critical Current ◽  
Current Density ◽  
Flux Pinning ◽  
Hole Concentration ◽  
Oxygen Deficiency ◽  
Magnetic Hysteresis ◽  
Zero Field ◽  
Different Temperatures

The nature of the temperature dependence of the zero-field critical current density, Jc0(T), in the CuO2 planes has been investigated for c-axis oriented YBa2Cu3O7-d (Y123) thin films over a range of hole content, p. The hole concentration was varied by changing the oxygen deficiency, d, in the CuO1-d chains by annealing the films under different oxygen partial pressures and temperatures. The Jc0(T) values were extracted from the magnetic hysteresis (M-H) loops obtained at different temperatures. From the analysis of the Jc0(T) data for different sample compositions, we have extracted valuable information regarding the nature of the underlying magnetic flux pinning mechanisms in Y123 superconductors. We have found that the oxygen defects play only a secondary role in pinning of the vortices, the superfluid density, on the other hand plays a significant role. The exponent, n, governing the Jc0(T) behavior for a given sample composition showed a systematic behavior as hole contents are changed. Keywords: Y123 superconductors; Critical current density; Flux pinning.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i2.9653 J. Sci. Res. 4 (2), 287-296 (2012)

Anisotropic critical current density and flux pinning mechanism of Fe1+yTe0.6Se0.4 single crystals

2021 ◽  
Author(s):  
Yongqiang Pan ◽  
Nan Zhou ◽  
Bencheng Lin ◽  
Jinhua Wang ◽  
Zengwei Zhu ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Single Crystals ◽  
Critical Current ◽  
Current Density ◽  
Flux Pinning ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Pinning Force ◽  
Magnetization Relaxation ◽  
Pinning Mechanism

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.

Temperature dependence of magnetic-field angle dependent critical current density and the flux pinning in YBa2Cu3O7 thin films

2012 ◽  
Vol 478 ◽  
pp. 19-28 ◽  
Author(s):  
H. Yamasaki ◽  
I. Yamaguchi ◽  
M. Sohma ◽  
W. Kondo ◽  
H. Matsui ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Critical Current Density ◽  
Temperature Dependence ◽  
Critical Current ◽  
Current Density ◽  
Flux Pinning

The effect of lead content on the critical current density, irreversibility field, and microstructure of Ag-clad Bi1.8PbxSr2Ca2Cu3Oy tapes

1999 ◽  
Vol 14 (2) ◽  
pp. 340-348 ◽  
Author(s):  
J. W. Anderson ◽  
S. E. Dorris ◽  
J. A. Parrell ◽  
D. C. Larbalestier
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Reaction Temperature ◽  
Current Density ◽  
Flux Pinning ◽  
Lead Content ◽  
Zero Field ◽  
Irreversibility Field ◽  
Phase Purity

We studied the effect of lead content (x = 0.20−0.40) on the critical current density Jc (0 T, 77 K), irreversibility field H* (77 K), and microstructure of monocore, Ag-clad Bi1.8PbxSr2Ca2Cu3Oy (2223) tapes, finding that tapes with lower lead contents (x = 0.20–0.25) required higher processing temperatures (840 and 832 °C, respectively) to complete 2223 formation, as compared to the optimum 820 °C reaction temperature of the x = 0.30–0.40 tapes. We found that both the zero-field and the in-field properties correlated strongly to the phase purity with Jc (0 T, 77 K) reaching a maximum of ˜20 kA/cm2 for x = 0.30, and then decreasing with increasing lead content to ˜12 kA/cm2 for x = 0.40. H* (77 K) increased from ˜165 mT at x = 0.20 to ˜265 mT at x = 0.30, then declined to 195 mT at x = 0.40. Optimizing the lead content at x = 0.30 maximized both the connectivity and the flux pinning contributions to the critical current density.

Temperature dependence of the intragrain critical current density in polycrystalline Ag-sheathed Bi(2223) tapes

1999 ◽  
Vol 9 (2) ◽  
pp. 2659-2662 ◽  
Author(s):  
G. Grasso ◽  
M.R. Cimberle ◽  
C. Ferdeghini ◽  
A.S. Siri ◽  
F. Marti ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Temperature Dependence ◽  
Critical Current ◽  
Current Density

Characterization of Epitaxial Superconducting YBacuO Thin Films with Three Different Orientations

1989 ◽  
Vol 169 ◽  
Author(s):  
X.K. Wang ◽  
D.X. Li ◽  
S.N. Song ◽  
J.Q. Zheng ◽  
R.P.H. Chang ◽  
...  
Keyword(s):  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Orientation Dependence ◽  
Zero Field ◽  
Epitaxial Thin Films ◽  
Oriented Film ◽  
Zero Resistance ◽  
Xrd Patterns

AbstractEpitaxial thin films of YBaCuO were prepared by multilayer deposition from Y, Cu, and BaF2 sources with: (1) the a‐axis perpendicular to (100)SrTiO3; (2) the c‐axis perpendicular to (100)SrTiO3; and (3) the [110] axis perpendicular to (110)SrTiO3. XRD patterns as well as SEM and HREM images confirm that the films are highly oriented, essentially epitaxial. Both the a‐axis oriented and the c‐axis oriented films exhibit zero resistance at 91K. The [110] oriented film shows the sharpest transiton with a transition width of IK and zero resistance at 85K. The zero field critical current density, Jc, determined magnetically, is in excess of 107A/cm2 at 4.4K and 1.04 x 106A/cm2 at 77K for the c‐axis oriented film; for the a‐axis oriented film we obtained 6.7 x 106A/cm2 at 4.4K and 1.2 x 105A/cm2 at 77K. The orientation dependence of the critical current density in the basal plane of the a‐axis oriented film was studied. The largest Jc's occur along the in‐plane <100> axes of the substrate.

Critical current density and flux pinning in Gd1−xYxBa2Cu3O7−y epitaxial thin films

1995 ◽  
Vol 250 (1-2) ◽  
pp. 55-58 ◽  
Author(s):  
R.L. Wang ◽  
H.C. Li ◽  
B. Yin ◽  
J.W. Li ◽  
X.S. Ron ◽  
...  
Keyword(s):  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Flux Pinning ◽  
Epitaxial Thin Films

Enhancement of flux pinning and high-field critical current density in carbon-alloyedMgB2thin films

2006 ◽  
Vol 74 (17) ◽  
Author(s):  
J. Chen ◽  
V. Ferrando ◽  
P. Orgiani ◽  
A. V. Pogrebnyakov ◽  
R. H. T. Wilke ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Flux Pinning ◽  
High Field
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