scholarly journals Critical Current Density of the Ferromagnetic Superconductor UGe2 near the Superconducting Transition Temperature

2020 ◽  
Author(s):  
Akira Yamaguchi ◽  
Tomoya Kotani ◽  
Atsushi Ogura ◽  
Ikuto Kawasaki ◽  
Akihiko Sumiyama ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Superconducting Transition Temperature ◽  
Superconducting Transition

Radiation Damage in YBa2Cu3O7 by Fast Neutrons

1987 ◽  
Vol 99 ◽  
Author(s):  
J. O. Willis ◽  
J. R. Cost ◽  
R. D. Brown ◽  
J. D. Thompson ◽  
D. E. Peterson
Keyword(s):  
Transition Temperature ◽  
Critical Current Density ◽  
Fast Neutron ◽  
Critical Current ◽  
Current Density ◽  
Superconducting Transition Temperature ◽  
Fast Neutrons ◽  
Zero Field ◽  
Superconducting Transition ◽  
Fast Neutron Irradiation

ABSTRACTThe superconducting transition temperature of sintered YBa2Cu3O7 decreases at a rate of 2.7 K/1018 n/cm2 (E > 0.1 MeV) for fast neutron irradiation. The critical current density Jc increases a factor of three at zero field and more than three at nonzero fields for fluences up to 2×1018 n/cm2. At both 7 and 75 K, Jc is decreasing with fluence near 3×1018 n/cm2.

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.

High Pressure Synthesized Magnesium Diboride- and Dodecaboride-Based Superconductors: Structure and Properties

2010 ◽  
Vol 670 ◽  
pp. 21-27 ◽  
Author(s):  
Tatiana Prikhna ◽  
Wolfgang Gawalek ◽  
Yaroslav Savchuk ◽  
Athanasios G. Mamalis ◽  
Vasiliy Tkach ◽  
...  
Keyword(s):  
High Pressure ◽  
Transition Temperature ◽  
Critical Current Density ◽  
Current Density ◽  
Magnesium Diboride ◽  
Synthesis Temperature ◽  
Superconducting Transition ◽  
Structure And Properties ◽  
Synthesized Materials ◽  
Critical Current Density Jc

The critical current density, jc, of high-pressure synthesized MgB2-based balk materials correlates with the amount and distribution of higher borides (MgB12) and Mg-B-O inclusions, which in tern correlates with the synthesis temperature and presence of additions (Ti, Ta, SiC). High-pressure-synthesized materials with near MgB12 composition of matrix exhibited superconducting transition temperature, Tc, of about 37 K, rather high jc (5∙105 and 103 A/cm2 in 0 T and 3.5 T, respectively, at 20 K) and doubled matrix microhardness: 25±1.1 GPa at 4.9 N –load as compared to materials with MgB2).

Influence of deposition rate on the properties of thick YBa2Cu3O7–δ films

1997 ◽  
Vol 12 (11) ◽  
pp. 2941-2946 ◽  
Author(s):  
S. R. Foltyn ◽  
E. J. Peterson ◽  
J. Y. Coulter ◽  
P. N. Arendt ◽  
Q. X. Jia ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Deposition Rate ◽  
Current Density ◽  
Oxygen Deficiency ◽  
Lattice Parameter ◽  
High Rate ◽  
Superconducting Transition ◽  
And Performance ◽  
Low Rate

To investigate potential limits to the rate at which high-quality YBa2Cu3O7–δ can be deposited, we have produced a series of 1 μm thick films by pulsed laser deposition on single-crystal SrTiO3 substrates at average rates ranging from 2 Å/s to 240 Å/s. The critical current density of low-rate films was over 2 MA/cm2 at 75 K, self field, but dropped linearly with rate to about 1 MA/cm2 at the upper end of the range. In addition, the superconducting transition temperature, resistivity above the transition, and performance in an applied magnetic field were all degraded by increasing the deposition rate. A change in c-axis lattice parameter suggests that possible causes for this degradation are oxygen deficiency or cation disorder with the latter being the more likely. Annealing high-rate films at 790 °C for as little as 20 min improved critical current density to within 20% of low-rate values, and resulted in dramatic improvements in other film properties as well.

Crystal Growth of High Temperature Superconductors

MRS Bulletin ◽  
1988 ◽  
Vol 13 (10) ◽  
pp. 56-61 ◽  
Author(s):  
H.J. Scheel ◽  
F. Licci
Keyword(s):  
High Temperature ◽  
Critical Current Density ◽  
Single Crystals ◽  
Critical Current ◽  
Current Density ◽  
Large Scale ◽  
High Temperature Superconductivity ◽  
High Temperature Superconductors ◽  
Superconducting Transition ◽  
Theoretical Understanding

The discovery of high temperature superconductivity (HTSC) in oxide compounds has confronted materials scientists with many challenging problems. These include the preparation of ceramic samples with critical current density of about 106 A/cm2 at 77 K and sufficient mechanical strength for large-scale electrotechnical and magnetic applications and the preparation of epitaxial thin films of high structural perfection for electronic devices.The main interest in the growth of single crystals is for the study of physical phenomena, which will help achieve a theoretical understanding of HTSC. Theorists still do not agree on the fundamental mechanisms of HTSC, and there is a need for good data on relatively defect-free materials in order to test the many models. In addition, the study of the role of defects like twins, grain boundaries, and dislocations in single crystals is important for understanding such parameters as the critical current density. The study of HTSC with single crystals is also expected to be helpful for finding optimum materials for the various applications and hopefully achieving higher values of the superconducting transition temperature Tc than the current maximum of about 125 K. It seems unlikely at present that single crystals will be used in commercial devices, but this possibility cannot be ruled out as crystal size and quality improve.

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.

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