Superconducting field effect devices with high transition temperature and critical current density

1995 ◽  
Vol 5 (2) ◽  
pp. 2872-2874 ◽  
Author(s):  
C. Doughty ◽  
V. Talyansky ◽  
C. Kwon ◽  
A.T. Findikoglu ◽  
X.X. Xi ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Field Effect ◽  
High Transition Temperature ◽  
Field Effect Devices ◽  
High Transition

Critical Current Density Enhancement and Moisture Destruction Studies of the Compound Superconductor Y-Ba-Cu-Ag-O

1987 ◽  
Vol 99 ◽  
Author(s):  
Y. D. Yao ◽  
A. Krol ◽  
Y. H. Krol ◽  
C. Walters ◽  
S. Spagna ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Moisture Treatment ◽  
Density Enhancement ◽  
Order Of Magnitude ◽  
High Transition ◽  
Moisture Conditions ◽  
State Resistance

ABSTRACTWe have fabricated a series of samples of YBa2(Cu1−x Agx)3Oy compounds where 0 ≤ × ≤ 1, with the intention to study the changes in critical current density and the effect of moisture treatment on normal state resistance R in these high transition-temperature superconductors. The samples exhibited a decrease of the transition-temperature Tc vs the Ag concentration x. Tc is about 93 K for YBa2Cu3Oy and 20 KCfor YBa2Ag3Oy, but it is almost unaffected by the presence or Ag for × < 0.2. An enhancement of the critical current density Jc by nearly an order of magnitude for the samples with 0 < × ≤ 0.1 has been observed. Both Jc and R are found to be sensitive to the ambient moisture conditions.

Characterization of superconducting SmBa2Cu3O7 films grown by pulsed laser deposition

2002 ◽  
Vol 17 (10) ◽  
pp. 2599-2603 ◽  
Author(s):  
Q. X. Jia ◽  
S. R. Foltyn ◽  
J. Y. Coulter ◽  
J. F. Smith ◽  
M. P. Maley
Keyword(s):  
Transition Temperature ◽  
Critical Current Density ◽  
Pulsed Laser Deposition ◽  
Critical Current ◽  
Current Density ◽  
Deposition Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Superconducting Transition ◽  
Transition Width

We have investigated epitaxial superconducting SmBa2Cu3O7 (Sm123) films grown by pulsed-laser deposition on single-crystal SrTiO3 substrates. The deposition temperature plays an important role in determining the superconducting properties of Sm123 films. The superconducting transition temperature increases with the deposition temperature whereas the transition width decreases at deposition temperatures in the range of 700–875 °C. A Sm123 film deposited at 850 °C exhibits a transition temperature above 93 K with a transition width less than 0.5 K. Even though Sm123 films exhibit a higher transition temperature than Yba2Cu3O7 (Y123), the Sm123 shows lower critical current density at liquid-nitrogen temperature. The nominal critical current density of Sm123 film is less than 1 MA/cm2 at 75.4 K. Nevertheless, the Sm123 films have less anisotropy and stronger pinning characteristics compared to Y123. They are also much smoother with fewer particulates, as revealed by scanning electron microscopy.

Phase Formation and Transport Critical Current Density of Tl2Ba2CaCu2O8 Superconductor with Nano Bi2O3

2017 ◽  
Vol 268 ◽  
pp. 320-324
Author(s):  
I.M.O. Dabaa ◽  
Roslan Abd-Shukor
Keyword(s):  
Transition Temperature ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Liquid Nitrogen Temperature ◽  
Solid State Reaction Method ◽  
Mixed Phase ◽  
Transport Critical Current Density ◽  
High Porosity ◽  
Grain Size And Orientation

The effect of nanosized Bi2O3 (150 nm) on the formation of the Tl2Ba2CaCu2O8 (Tl-2212) phase, transition temperature and transport critical current density has been studied. Samples with nominal starting composition Tl2Ba2CaCu2O8(Bi2O3)x (x = 0 to 0.5 wt. %) were prepared using the solid state reaction method. Most samples except x = 0.5 showed a mixed phase consisting of the Tl2Ba2CaCu2O8 and Tl2Ba2Ca2Cu3O10 (Tl-2223). The x = 0.5 sample showed a single Tl-2212 phase. However, the transition temperature, Tc of the x = 0.5 was very much suppressed (Tonset = 106 K, Tc zero 88 K). All samples showed random grain size and orientation, with partial melting and high porosity. The x = 0.1 mixed phase sample showed the highest transport critical current density of 285 mA/cm2 at liquid nitrogen temperature (78 K).

Supraleiter mit Schichten der A 15-Phasen Nb-Al und Nb-Al-Ge / Superconductor with Layer of the A 15-Phase Nb-Al(Ge)

1974 ◽  
Vol 29 (1) ◽  
pp. 99-106
Author(s):  
A. Müller
Keyword(s):  
Heat Treatment ◽  
Transition Temperature ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Outer Layer ◽  
Subsequent Heat Treatment ◽  
Products Of Reaction ◽  
A15 Phase

A conductor has been prepared, consisting of Niobium and an outer layer of the A15-phase Nb-Al and Nb-Al-Ge respectively. The process involves two steps: Coating of Niobium by hotdipping and subsequent heat treatment. The procedure, the products of reaction and data on the transition temperature Tc and the critical current density J c of the A15-phase are reported. The maximum values obtained for Tc and J c are 18.5 K (19.3 K) and 5 · 104 A/cm2 (2 · 104 A/cm2) at 5 T and 4.2 K for Nb3Al (Nb3Al, Ge).

CRITICAL CURRENT AND TRANSITION TEMPERATURE WIDTH IN OXIDE SUPERCONDUCTORS UNDER PRESSURE

1990 ◽  
Vol 04 (10) ◽  
pp. 645-650 ◽  
Author(s):  
V. M. SVISTUNOV ◽  
V. YU. TARENKOV ◽  
YU. F. REVENKO ◽  
O. I. CHERNJAK ◽  
A. I. D'YACHENKO ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Oxide Superconductors ◽  
Twin Boundaries

The critical current density of Y-based and Bi-based high-T c superconductors has been measured under pressure. The substantial increase of j c with pressure is found. The results of our measurements can be explained if the sample is regarded as a network of S-N-S junctions with arbitrary parameters. These junctions can be formed by integrain layers and/or twin boundaries.

The Influence of Sintering Time in High and Low Density Bi-2223 Superconductor

2015 ◽  
Vol 1107 ◽  
pp. 616-621
Author(s):  
M. Robaiah ◽  
H. Azhan ◽  
K. Azman ◽  
I.N. Syuhaida ◽  
C.M.N. Azura ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Volume Fraction ◽  
Solid State Reaction Method ◽  
Zero Magnetic Field ◽  
Low Density ◽  
X Ray Diffraction ◽  
Sintering Time

The effects of sintering time in high and low density Bi-2223 phase formation have been investigated. The samples were prepared by the solid-state reaction method at various sintering times ranging from 24, 48, 72 and 96 hours. Sucrose was added during palletization and after heated at 400°C for two hours the sucrose was removed and hence low density sample was created. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and critical current density. The transition temperature varies between 102 K and 96 K with increasing of sintering times. The optimal sintering time of the samples Bi-2223 system was found at 850°C for 72 hours. The critical current density,JCof high density and low density Bi-2223 was measured to be 7.547 A/cm2and 8.333 A/cm2respectively at 77 K under zero magnetic field. The critical current density,JCand superconductivity transition temperature,TCof low density were found to be higher than the pure samples. The critical transition temperature increased with a short gap betweenTConsetandTC zero. The most intense peak in the XRD pattern of sample at sintering time 72 hours belong to the high-TCphase which also indicates an increase in the volume fraction of the high-TCphase with optimum sintering time.

Transport Critical Current Density and Flux Pinning Enhancement in Nano-Sized PbO and HfO2 Added (Bi1.6Pb0.4)Sr2Ca2Cu3O10 Superconductor

2015 ◽  
Vol 1108 ◽  
pp. 85-90
Author(s):  
Nabil A.A. Yahya ◽  
R. Abd-Shukor
Keyword(s):  
Particle Size ◽  
Transition Temperature ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Flux Pinning ◽  
Homogeneous Distribution ◽  
Transport Critical Current Density ◽  
Superconducting Properties ◽  
Pinning Centers

A comparative study on the effect of PbO (10-30 nm) and HfO2 (60-80 nm) additions on the superconducting properties of (Bi1.6Pb0.4)Sr2Ca2Cu3O10 ((Bi,Pb)-2223) superconductor in the bulk form was carried out. The structure and the microstructure of prepared samples were examined by powder XRD and SEM, respectively. The transition temperature Tc and critical current density Jc was determined by standard dc four-probe method. SEM micrographs showed a homogeneous distribution of Pb and Hf in the samples. It was observed that PbO and HfO2 additions enhanced Jc for all added samples. Jc was the highest for x= 0.05 wt. % of PbO (1130 mA/cm2 at 77 K and 1930 mA/cm2 at 30 K) and HfO2 (900 mA/cm2 at 77 K and 1760 mA/cm2 at 30 K) addition. This study showed that the addition of PbO and HfO2 nanopowder provided extra flux pinning centers in the (Bi, Pb)-2223. PbO with smaller particle size showed higher Jc compared with HfO2 which has a larger particle size.

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