Influence of the grain boundary network on the critical current density of deformation-texturedYBa2Cu3O7−xcoated conductors made by metal-organic deposition

2005 ◽  
Vol 71 (10) ◽  
Author(s):  
S. I. Kim ◽  
D. M. Feldmann ◽  
D. T. Verebelyi ◽  
C. Thieme ◽  
X. Li ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Metal Organic ◽  
Metal Organic Deposition

The Effect of Polyethyleneimine (PEI) on the Texture and Morphology of YBCO Films

2013 ◽  
Vol 833 ◽  
pp. 103-106 ◽  
Author(s):  
Wan Chen Xu ◽  
Yue Ling Bai ◽  
Jian Hui Fang ◽  
Chuan Bing Cai
Keyword(s):  
Thin Film ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Precursor Solution ◽  
Superconducting Properties ◽  
Axis Orientation ◽  
Ybco Films ◽  
Metal Organic ◽  
Metal Organic Deposition

The effect of polyethyleneimine (PEI) in precursor solution on the morphology and superconducting properties of YBa2Cu3O7-x (YBCO) films grown on LaAlO3 (LAO) substrates by metal-organic deposition (MOD) method was investigated. The morphologies of the YBCO films were different based on the different amount of PEI addition from 0.25 g to 0.9 g in 10 mL precursor solution. Furthermore, research results indicate that the PEI helps to improve the critical current density (Jc), the uniformity of surface morphology and c-axis orientation of thin film. The highest critical current density (Jc) of 2.17 MA/cm2 at 77 K is obtained in YBCO films fabricated on LAO substrates when the amount of PEI is 0.5 g in 10 mL precursor solution. YBCO layers with about 400 nm in thickness can be processed without cracks and holes during the whole heat treatment, which takes only 7.5 h.

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.

Increased grain boundary critical current density Jcgb by Pr-doping in pulsed laser–deposited Y1−xPrxBCO thin films

2011 ◽  
Vol 110 (11) ◽  
pp. 113905 ◽  
Author(s):  
M. Irjala ◽  
H. Huhtinen ◽  
V. P. S. Awana ◽  
M. Falter ◽  
P. Paturi
Keyword(s):  
Thin Films ◽  
Grain Boundary ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Pulsed Laser

Grain Boundary Structure and Properties of High-Tc Superconductors

1992 ◽  
Vol 275 ◽  
Author(s):  
K. Jagannadham ◽  
J. Narayan
Keyword(s):  
Grain Boundary ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Boundary Effects ◽  
Boundary Structure ◽  
Excess Charge ◽  
High Tc Superconductors ◽  
High Tc ◽  
Grain Boundary Structure

ABSTRACTWe have modelled the grain boundaries in high-Tc superconducting oxides and determined the critical current density. The tunneling of superconducting pairs across the coalesced regions is used to determine the boundary effects. The length of the coalesced regions, with continuity of the Cu-O planes maintained by relaxation of the atom positions, is determined by minimization of the energy of the configuration. The depression of the order parameter is evaluated using the continuity conditions at the boundary in the proximity effect formulation. The excess charge distribution at the core of the boundary, determined from the solution to the Poisson's equation, is used to determine the scattering of the superconducting pairs. The width of the boundary, evaluated from modelling, determines the transmission coefficient for tunnelingof superconducting pairs. The critical current density is expressed in terms of these four important factors associated with the grain boundary. All the experimental results are explained by the present modelling of the grain boundary effects.

Grain boundary microstructure and transport critical current density in YBa2Cu3Ox

1992 ◽  
Author(s):  
Donglu Shi ◽  
Yufei Gao ◽  
A. C. Biondo ◽  
J. G. Chen ◽  
K. L. Merkle ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Transport Critical Current Density ◽  
Boundary Microstructure
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