scholarly journals Huge critical current density and tailored superconducting anisotropy in SmFeAsO0.8F0.15 by low-density columnar-defect incorporation

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
L. Fang ◽  
Y. Jia ◽  
V. Mishra ◽  
C. Chaparro ◽  
V. K. Vlasko-Vlasov ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Low Density ◽  
Columnar Defect

The Influence of Sintering Time in High and Low Density Bi-2223 Superconductor

2015 ◽  
Vol 1107 ◽  
pp. 616-621
Author(s):  
M. Robaiah ◽  
H. Azhan ◽  
K. Azman ◽  
I.N. Syuhaida ◽  
C.M.N. Azura ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Volume Fraction ◽  
Solid State Reaction Method ◽  
Zero Magnetic Field ◽  
Low Density ◽  
X Ray Diffraction ◽  
Sintering Time

The effects of sintering time in high and low density Bi-2223 phase formation have been investigated. The samples were prepared by the solid-state reaction method at various sintering times ranging from 24, 48, 72 and 96 hours. Sucrose was added during palletization and after heated at 400°C for two hours the sucrose was removed and hence low density sample was created. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and critical current density. The transition temperature varies between 102 K and 96 K with increasing of sintering times. The optimal sintering time of the samples Bi-2223 system was found at 850°C for 72 hours. The critical current density,JCof high density and low density Bi-2223 was measured to be 7.547 A/cm2and 8.333 A/cm2respectively at 77 K under zero magnetic field. The critical current density,JCand superconductivity transition temperature,TCof low density were found to be higher than the pure samples. The critical transition temperature increased with a short gap betweenTConsetandTC zero. The most intense peak in the XRD pattern of sample at sintering time 72 hours belong to the high-TCphase which also indicates an increase in the volume fraction of the high-TCphase with optimum sintering time.

Structural and Superconducting Properties of Bi-Based Low Density HTSC

2015 ◽  
Vol 1107 ◽  
pp. 606-610
Author(s):  
C.M.N. Azura ◽  
H. Azhan ◽  
K. Azman ◽  
I.N. Syuhaida ◽  
M. Robaiah ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Polycrystalline Sample ◽  
Effective Area ◽  
Nominal Composition ◽  
Low Density ◽  
Superconducting Properties ◽  
Probe Field ◽  
Current Flows

Low density HTSC with nominal composition of Bi1.6Pb0.4Sr2Ca2Cu3Oy filled with crystalline sucrose has been synthesized and its structucal and superconducting properties have been studied. The transport properties, morphology, density and structural identification were determined by using the standard four point probe, Field Emission Scanning Electron Microscope (FESEM), densitometer and X-ray diffraction (XRD) respectively. The critical current density (Jc) of optimized ratio of crystalline sucrose onto Bi-2223 powder used to produce low density Bi-based superconductor was found to be higher than the bulk polycrystalline sample. TC zero obtained was varied between 93 and 101 K towards the increment ratio of crystalline sucrose with the highest TC zero = 101 K for ratio of 0.050:1.950 and decrease gradually for further addition of cystalline sucrose. The crystallographic structures was found to be remained in tetragonal where a=b≠c. The grains with higher porosity resulting in decreasing of critical current density (Jc) as well as critical temperature (Tc zero) due to lack of effective area of current flows.

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

Facet Topography and Dislocation Structure as a Possible Source for Electrical Heterogeneity in [001] TILT Bicrystals of YBa2Cu3O7-δ

1996 ◽  
Vol 54 ◽  
pp. 338-339
Author(s):  
I-Fei Tsu ◽  
D.L. Kaiser ◽  
S.E. Babcock
Keyword(s):  
Grain Boundary ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Electromagnetic Properties ◽  
Length Scale ◽  
Density Values ◽  
Current Densities ◽  
Applied Fields ◽  
A Current

A current theme in the study of the critical current density behavior of YBa2Cu3O7-δ (YBCO) grain boundaries is that their electromagnetic properties are heterogeneous on various length scales ranging from 10s of microns to ˜ 1 Å. Recently, combined electromagnetic and TEM studies on four flux-grown bicrystals have demonstrated a direct correlation between the length scale of the boundaries’ saw-tooth facet configurations and the apparent length scale of the electrical heterogeneity. In that work, enhanced critical current densities are observed at applied fields where the facet period is commensurate with the spacing of the Abrikosov flux vortices which must be pinned if higher critical current density values are recorded. To understand the microstructural origin of the flux pinning, the grain boundary topography and grain boundary dislocation (GBD) network structure of [001] tilt YBCO bicrystals were studied by TEM and HRTEM.

Effects of surface damage on critical current density in MgB2 thin films

2021 ◽  
Vol 22 ◽  
pp. 14-19
Author(s):  
Soon-Gil Jung ◽  
Duong Pham ◽  
Jung Min Lee ◽  
Yoonseok Han ◽  
Won Nam Kang ◽  
...  
Keyword(s):  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Surface Damage ◽  
Mgb2 Thin Films
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