Grain-Boundary Josephson Junctions in the High-Temperature Superconductors

1994 ◽  
pp. 176-209 ◽  
Author(s):  
Rudof Gross
Keyword(s):  
High Temperature ◽  
Grain Boundary ◽  
Josephson Junctions ◽  
High Temperature Superconductors

Fabrication of Inductively-Coupled Double-Josephson Junctions Using High-Temperature Superconductors

2007 ◽  
Vol 17 (2) ◽  
pp. 959-962 ◽  
Author(s):  
T. Kimura ◽  
M. Watanabe ◽  
M. Sugimoto ◽  
Y. Fukai ◽  
M. Inoue ◽  
...  
Keyword(s):  
High Temperature ◽  
Josephson Junctions ◽  
High Temperature Superconductors ◽  
Inductively Coupled

Site Exchange in High Temperature Superconductors

1987 ◽  
Vol 99 ◽  
Author(s):  
D. J. Li ◽  
H. Shibahara ◽  
J. P. Zhang ◽  
L. D. Marks
Keyword(s):  
Heavy Metals ◽  
High Temperature ◽  
Grain Boundary ◽  
High Temperature Superconductors ◽  
Planar Defects ◽  
Electron Microscopical Analysis ◽  
Site Exchange ◽  
Copper Sites ◽  
Electron Microscopical ◽  
Brown Powder

ABSTRACTElectron microscopical analysis of brown powders of composition YBa2Cu3O6.5 produced by oil quenching and conventionally produced orthorhombic GdBa2Cu3O7-δ show in both cases clear evidence for site exchange both between the different heavy metals and the heavy metals and the copper sites. For instance, the brown powder is a mixture of phases which are based upon two trigonal phases, both with a=0.536 and c=0.666 nm, one with the Y atoms stacked on the (111) planes of the parent perovskite structure and the second where the Y atoms of this structure have interchanged with one of the copper sites. The GdBa2Cu3O7-δ, material shows numerous planar defects on (001) planes which can be understood as copper rich regions with additional copper planes in the Ba or Gd sites. These results, together with earlier reports of order-disorder in YBa2Cu3O7-δ, strongly indicate that there exist ordering energies in these materials which may be important with respect to the current indications of the important of grain boundary phases in degrading the performance of some superconductors.

Three Terminal HTc Vortex Flow Transistors: Optimisation of the Device Geometry Employing Bicrystal Grain-Boundary Josephson Junctions

1999 ◽  
Vol 13 (09n10) ◽  
pp. 1253-1258
Author(s):  
V. Granata ◽  
B. A. Davidson ◽  
E. Sarnelli ◽  
S. Pagano
Keyword(s):  
High Temperature ◽  
Grain Boundary ◽  
Vortex Dynamics ◽  
High Frequency ◽  
Josephson Junctions ◽  
Vortex Flow ◽  
Operating Regime ◽  
Bias Current ◽  
Advantages And Disadvantages ◽  
Geometric Configurations

We have numerically studied the static and dynamic behavior of a three terminal vortex-flow transistor based on a parallel array of Josephson junctions. We explicitly show advantages and disadvantages for different device geometric configurations, systematically changing the symmetry of the bias-current distribution. Using parameters typical of high-temperature superconducting junctions at 77K, we have analysed for each configuration the dependence of the critical current on the control current, and the voltage-current curves. We have calculated gain and transresistance for different bias conditions, and explained the numerical results in terms of the vortex dynamics in the array. This study allows us to establish limits for the operating regime of these devices when used as high-frequency amplifiers.

Dynamical Properties of Weakly Coupled Josephson Systems

1990 ◽  
Vol 195 ◽  
Author(s):  
K. H. Lee ◽  
T.-K. Xia ◽  
D. Stroud
Keyword(s):  
High Temperature ◽  
Magnetic Fields ◽  
Harmonic Generation ◽  
Finite Temperature ◽  
Josephson Junctions ◽  
High Temperature Superconductors ◽  
Dynamical Behavior ◽  
Critical Currents ◽  
Weakly Coupled ◽  
Dynamical Properties

ABSTRACTWe review recent work on the dynamical behavior of coupled resistively-shunted Josephson junctions, with emphasis on our own calculations. We present a model which allows for the inclusion of finite temperature, disorder, d.c. and a. c. applied currents, and applied magnetic fields. We discuss applications to (a) calculations of critical currents and IV characteristics; (b) harmonic generation and microwave absorption by finite clusters of Josephson junctions; (c) critical energies for vortex depinning; and (d) quantized voltage plateaus in arrays subjected to combined d.c. and a. c. currents. Possible connections to the behavior of granular high-temperature superconductors are briefly discussed.

Non-Stoichiometry at Dislocation Cores in Perovskites and Related Materials

2001 ◽  
Vol 7 (S2) ◽  
pp. 306-307
Author(s):  
Gerd Duscher ◽  
M. Kim ◽  
N.D. Browning ◽  
D. K. Christen ◽  
C. Cantoni ◽  
...  
Keyword(s):  
High Temperature ◽  
Grain Boundary ◽  
High Temperature Superconductors ◽  
Small Sample ◽  
Structural Units ◽  
Band Bending ◽  
Single Grain ◽  
Z Contrast ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

Z-contrast images and electron energy loss spectra (EELS) were obtained from low angle grain boundaries in SrTiO3 and YBa2Cu3O7-x (YBCO). Z-contrast images are easy to interpret and especially useful for positioning the beam to acquire EELS data from small sample areas [1], because both these techniques can be performed simultaneously.In high-temperature superconductors even a single grain boundary can reduce the critical current by up to four orders of magnitude. The band-bending model can quantitatively explain this phenomenon. YBCO is a hole-doped superconductor with about one hole per unit cell for optimum doping at x close to zero. It has a structure closely related to the perovskite structure, and Z-contrast images have shown that the dislocation cores are made up of similar structural units as in SrTiO3.[2,3] Our EELS measurements show clear evidence for band bending effects around isolated dislocation cores in an undoped 8° low angle grain boundary.

Current transport of the [001]-tilt low-angle grain boundary in high temperature superconductors

2013 ◽  
Vol 103 (23) ◽  
pp. 232602 ◽  
Author(s):  
Donghua Yue ◽  
Xingyi Zhang ◽  
Jun Zhou ◽  
Youhe Zhou
Keyword(s):  
High Temperature ◽  
Grain Boundary ◽  
High Temperature Superconductors ◽  
Current Transport

Conductance zero bias anomaly in high temperature superconducting grain boundary Josephson junctions

1996 ◽  
Vol 46 (S3) ◽  
pp. 1303-1304 ◽  
Author(s):  
P. Richter ◽  
A. Beck ◽  
O. M. Froehlich ◽  
R. Gross ◽  
G. Koren
Keyword(s):  
High Temperature ◽  
Grain Boundary ◽  
Josephson Junctions ◽  
Zero Bias ◽  
High Temperature Superconducting ◽  
Zero Bias Anomaly
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