Effective-barrier-thickness fluctuation and critical-current spread of grain-boundary Josephson junctions

2008 ◽  
Vol 92 (10) ◽  
pp. 103511 ◽  
Author(s):  
J. T. Jeng ◽  
C. H. Wu
Keyword(s):  
Grain Boundary ◽  
Critical Current ◽  
Josephson Junctions ◽  
Barrier Thickness ◽  
Effective Barrier ◽  
Current Spread

Phenomenology of YBa2Cu3O7-x Grain Boundary Josephson Junctions Irradiated by an Electron Beam

1999 ◽  
Vol 13 (09n10) ◽  
pp. 1307-1314
Author(s):  
F. Tafuri ◽  
B. Nadgorny ◽  
S. Shokor ◽  
M. Gurvitch ◽  
F. Carillo ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Electron Beam ◽  
Grain Boundary ◽  
Electron Irradiation ◽  
Josephson Junctions ◽  
Electron Beam Irradiation ◽  
Isothermal Annealing ◽  
Barrier Thickness ◽  
Beam Irradiation ◽  
Frequency Tunability

Electron beam irradiation has been used to induce controllable variations in the properties of YBa 2 Cu 3 O 7-x biepitaxial grain boundary Josephson junctions. Electron irradiation decreased the critical current of the junctions IC and increased the normal state specific resistivities. The junction parameters can be adjusted controllably by applying an appropriate dose. The original properties of the junctions could be partly restored by isothermal annealing A correlation between the transport properties and the microstructure was obtained by determining the ratio of a barrier thickness to the dielectric constant of the junctions with different barriers. The experiment also demonstrates frequency tunability in a resonant soliton oscillator. Preliminar results of irradiation on (103) YBCO films have been given demonstrating differences from data on c -axis films, as partly expected from the anisotropy of these materials.

The influence of the critical current spread on the frequency locking of Josephson junctions in two-dimensional arrays

1998 ◽  
Vol 83 (10) ◽  
pp. 5302-5306 ◽  
Author(s):  
A. Laub ◽  
M. Keck ◽  
T. Doderer ◽  
R. P. Huebener ◽  
T. Traeuble ◽  
...  
Keyword(s):  
Critical Current ◽  
Josephson Junctions ◽  
Two Dimensional ◽  
Frequency Locking ◽  
Current Spread

Analysis of the critical current density in grain boundary Josephson junctions on a nanometer scale

1995 ◽  
Vol 66 (17) ◽  
pp. 2289-2291 ◽  
Author(s):  
O. M. Froehlich ◽  
H. Schulze ◽  
A. Beck ◽  
B. Mayer ◽  
L. Alff ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Josephson Junctions ◽  
Nanometer Scale

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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