Effects of lead content and particle size of precursor powders on formation rate, grain growth and critical current density of BSCCO 2223 tapes

2001 ◽  
Vol 11 (1) ◽  
pp. 3549-3552 ◽  
Author(s):  
Jaimoo Yoo ◽  
Jaewoong Ko ◽  
X.D. Su ◽  
Haidoo Kim ◽  
Hyungsik Chung
Keyword(s):  
Particle Size ◽  
Critical Current Density ◽  
Critical Current ◽  
Grain Growth ◽  
Current Density ◽  
Formation Rate ◽  
Lead Content ◽  
Precursor Powders

YBCO Bulk Superconductors with Sm Addition

2017 ◽  
Vol 891 ◽  
pp. 483-488 ◽  
Author(s):  
Daniela Volochová ◽  
Vitaliy Antal ◽  
Jozef Kováč ◽  
Pavel Diko
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Superconducting Properties ◽  
Ybco Bulk ◽  
Pinning Centers ◽  
Bulk Superconductors ◽  
Powder Addition ◽  
Current Densities ◽  
Precursor Powders

The influence of Sm addition on the microstructure and superconducting properties of Y-Ba-Cu-O (YBCO) bulk superconductors has been studied. Precursor powders YBa2Cu3O7-δ (Y-123), Y2O3 and CeO2 were enriched with different amounts of SmBa2Cu3Oy (Sm-123) or Sm2O3 powders with the aim to increase critical current density, Jc,by introducing additional pinning centers. YBCO bulk superconductors with SmBa2Cu3Oy (Y123-Sm) or Sm2O3 (Y123-SmO) powder addition were prepared by the optimized top seeded melt growth process in the form of single grains. Microstructure analysis revealed that Sm2O3 addition leads to a higher amount of smaller Y2BaCuO5 (Y-211) particles, what is related to high critical current densities (Jc ~ 7 x 104 A/cm2) of the YBCO samples with Sm2O3 addition in low magnetic fields. The effect of Sm addition in the form of SmBa2Cu3Oy as well as Sm2O3 powder on Y2BaCuO5 particle size, critical temperature, Tc, and critical current density, Jc, is reported.

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.

Crystallization of A15 Nb3Ge from the amorphous state

1990 ◽  
Vol 5 (3) ◽  
pp. 478-483
Author(s):  
Marcin Wardak ◽  
Mireille Treuil Clapp
Keyword(s):  
Grain Size ◽  
Critical Current Density ◽  
Critical Current ◽  
Grain Growth ◽  
Current Density ◽  
Amorphous Material ◽  
Amorphous State ◽  
Average Grain Size ◽  
Melt Spun ◽  
Melt Spun Ribbons

The critical current density Jc of superconductors is strongly dependent on microstructure. The microstructure and crystallization of amorphous Nb75Ge24.5B0.5 melt spun ribbons were studied as a function of 24-h anneals between 680 and 860 °C. Metastable A15 was formed with a composition close to that of the starting amorphous material. As the temperature increased from 680 to 720°C, crystallization remained nonuniform and the average grain size decreased from 130 nm to 60 nm. Between 740 and 800°C crystallization was uniform and the average grain size was constant at 30 nm. Above 820°C grain growth occurred. In order to have high Jc's a uniformly crystallized small-grained material is desirable.

INDUCTANCE TECHNIQUE FOR MEASURING TRANSITION TEMPERATURES OF SUPERCONDUCTING POWDERS

1989 ◽  
Vol 03 (05) ◽  
pp. 763-772 ◽  
Author(s):  
T. K. VETHANAYAGAM ◽  
W. A. SCHULZE ◽  
J. A. T. TAYLOR ◽  
R. L. SNYDER
Keyword(s):  
Particle Size ◽  
Critical Current Density ◽  
Sample Size ◽  
Critical Current ◽  
Current Density ◽  
Superconducting State ◽  
Simple Technique ◽  
Electrical Contacts ◽  
Powder Samples ◽  
Effect Of Particle Size

A simple technique to measure T c of superconducting powder samples is evaluated. Inductance of the sample is used as the indicator to determine the behavior of the material as it goes to the superconducting state. The effect of particle size and sample size on the measured parameters has been investigated. The main advantages of this technique are the absence of electrical contacts and the elimination of the need for sintered bars. The technique has the potential to measure the amount of superconducting phases as well as the critical current density.

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