Alternating current susceptibility calculations for thin-film superconductors with regions of different critical-current densities

2008 ◽  
Vol 103 (11) ◽  
pp. 113907 ◽  
Author(s):  
C. Navau ◽  
A. Sanchez ◽  
N. Del-Valle ◽  
D.-X. Chen
Keyword(s):  
Thin Film ◽  
Critical Current ◽  
Alternating Current ◽  
Current Densities

Transport Measurements on Superconducting YBa2Cu3O7-δ Thin Film Lines

1989 ◽  
Vol 169 ◽  
Author(s):  
B. H. Moeckly ◽  
D. K. Lathrop ◽  
G. F. Redinbo ◽  
S. E. Russek ◽  
R. A. Buhrman
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Critical Current ◽  
Weak Link ◽  
High Sensitivity ◽  
Weak Links ◽  
Microwave Response ◽  
Field Response ◽  
Current Densities ◽  
Iv Curves

AbstractCritical current densities, magnetic field response, and microwave response have been measured for laser ablated YBa2Cu3O7-δ thin film lines on MgO and SrTiO3 substrates. Films on SrTiO3 have critical current densities > 1 x 106 A/cm2 at 77K and show uniform transport properties in lines of all sizes. Films on MgO have critical current densities which range between 102 and 106 A/cm2 at 77K and show considerable variation from device to device on the same chip. Narrow lines on MgO with low critical current densities show Josephson weak link structure which includes RSJ-like IV curves, microwave induced constant voltage steps, and a high sensitivity to magnetic field. The presence of the Josephson weak links is correlated with small amounts of misaligned grains in films on MgO.

Irreversibility line and critical current densities of an oxycarbonate thin film Ba2Ca3Cu4CO3O8

1995 ◽  
Vol 8 (5) ◽  
pp. 361-365 ◽  
Author(s):  
W Prellier ◽  
J L Allen ◽  
C Prouteau ◽  
C Simon ◽  
B Mercey
Keyword(s):  
Thin Film ◽  
Critical Current ◽  
Irreversibility Line ◽  
Current Densities

High Critical-Current Density Ba2YCu3O7 Thin Films Produced by Coevaporation of Y, Cu, and BaF2

1987 ◽  
Vol 99 ◽  
Author(s):  
P. M. Mankiewich ◽  
R. E. Howard ◽  
W. J. Skocpol ◽  
A. H. Dayem ◽  
A. Ourmazd ◽  
...  
Keyword(s):  
Thin Film ◽  
Critical Current ◽  
High Critical Current Density ◽  
High Quality ◽  
Residual Resistance ◽  
Substrate Interaction ◽  
Transmission Electron ◽  
Zero Resistance ◽  
Current Densities ◽  
Oxygen Addition

ABSTRACTHigh quality films of Ba2YCu3O7 have been made by coevaporation of Y, Cu, and BaF2 and subsequent annealing in oxygen. Addition of water vapor to the annealing gas at high temperatures has been found to greatly reduce the annealing time and, thus the substrate interaction. Transition temperatures (zero resistance) between 89–92 K are routinely obtained on SrTiO3 and cubic zirconia substrates. Critical current densities on SrTiO3 are as high as 106 A/cm2 at 81 K and routinely above 105 A/cm2 at 77 K. Transmission electron microscopy shows that on SrTiO3 the superconducting grains have an epitaxial orientation with respect to the substrate. Persistent current measurements in thin film rings demonstrate the absence of residual resistance in the superconducting state.

Critical Current Densities of Submillimeter Single-Grain Tl-2223 Superconducting Thin Film

1996 ◽  
Vol 35 (Part 2, No. 2B) ◽  
pp. L209-L212
Author(s):  
Han-Chi Lin ◽  
Jenh-Yih Juang ◽  
Kwong-Hsung Wu ◽  
Yih-Shung Gou ◽  
Tseng-Ming Uen
Keyword(s):  
Thin Film ◽  
Critical Current ◽  
Superconducting Thin Film ◽  
Current Densities ◽  
Single Grain

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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