Correlation between critical current density and n-value in MgB2/Nb/Monel superconductor wires

2010 ◽  
Vol 470 (20) ◽  
pp. 1207-1210 ◽  
Author(s):  
J.H. Kim ◽  
S.X. Dou ◽  
A. Matsumoto ◽  
S. Choi ◽  
T. Kiyoshi ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
N Value

Critical current density and n-value of NbTi wires at low field

1995 ◽  
Vol 5 (2) ◽  
pp. 1201-1204 ◽  
Author(s):  
Y. Inoue ◽  
H. Kurahashi ◽  
Y. Fukumoto ◽  
M. Shimada
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
N Value ◽  
Low Field

scholarly journals Power-Law Relationship Between Critical Current Density, Microstructure, and the n-Value in MgB2 Superconductor Wires

2014 ◽  
Vol 27 (7) ◽  
pp. 1643-1645 ◽  
Author(s):  
Ashkan Motaman ◽  
Shaon Barua ◽  
Dipak Patel ◽  
Minoru Maeda ◽  
Kookchae Cheong ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Power Law ◽  
Current Density ◽  
Mgb2 Superconductor ◽  
N Value

scholarly journals Influence of Multiple Angled Columnar Defects on Critical Current Density and n–Value in YBCO Thin Films

2012 ◽  
Vol 36 ◽  
pp. 1570-1575 ◽  
Author(s):  
Tetsuro Sueyoshi ◽  
Takahiro Nishimura ◽  
Takanori Fujiyoshi ◽  
Fumiaki Mitsugi ◽  
Tomoaki Ikegami ◽  
...  
Keyword(s):  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
N Value ◽  
Ybco Thin Films ◽  
Columnar Defects

scholarly journals Influence of Amorphous Boron Grain Size, High Isostatic Pressure, Annealing Temperature, and Filling Density of Unreacted Material on Structure, Critical Parameters, N-Value, and Engineering Critical Current Density in Mgb2 Wires

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3600
Author(s):  
Daniel Gajda ◽  
Andrzej J. Zaleski ◽  
Andrzej Morawski ◽  
Małgorzata Małecka ◽  
Mustafa Akdoğan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Liquid State ◽  
Critical Parameters ◽  
Heterogeneous Structure ◽  
Synthesis Reaction ◽  
N Value

Our results show that a lower density of unreacted Mg + B material during an Mg solid-state synthesis reaction leads to a significant reduction in the quantity of the superconducting phase and lowers the homogeneity of the superconducting material. It also significantly reduces the irreversible magnetic field (Birr), critical temperature (Tc), upper magnetic field (Bc2), engineered critical current density (Jec), and n-value, despite high isostatic pressure (HIP) treatment and the use of nanoboron in the sample. Our measurements show that samples with large boron grains with an 8% higher density of unreacted Mg + B material allow better critical parameters to be achieved. Studies have shown that the density of unreacted material has little effect on Birr, Tc, Bc2, Jec, and the n-value for an Mg liquid-state synthesis reaction. The results show that the critical parameters during an Mg liquid-state synthesis reaction depend mainly on grain size. Nanoboron grains allow for the highest Birr, Tc, Bc2, Jec, and n-values. Scanning electron microscopy (SEM) images taken from the longitudinal sections of the wires show that the samples annealed under low isostatic pressure have a highly heterogeneous structure. High isostatic pressure heat treatment greatly improves the homogeneity of MgB2.

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.

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