Spatial variations in composition in high-critical-current-density Bi-2223 tapes

A detailed compositional analysis of high-critical-current-density (Jc) (55 and 65 kA/cm2at 77 K) (Bi,Pb)2Sr2Ca2Cu3Oy(Bi-2223) tapes was undertaken by energy dispersive spectroscopy in the transmission electron microscope. Structural features were coupled with characteristic compositions of the Bi-2223 phase. The average of all compositional measurements of the Bi-2223 phase was determined to be Bi1.88Pb0.23Sr1.96Ca1.95Cu2.98Oy. However, spatial variations in the Bi-2223 composition and differing phase equilibria were found throughout the filament structure. In particular, a considerable range of Bi-2223 compositions can be found within a single tape, and the lead content of the Bi-2223 phase is significantly depressed in the vicinity of lead-rich phases. The depletion of lead in the Bi-2223 phase around the 3221 phases may be a current-limiting microstructure in these tapes.

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FeSe superconducting tapes with a high critical current density fabricated by diffusion method

Journal of Physics Conference Series ◽

10.1088/1742-6596/400/2/022016 ◽

2012 ◽

Vol 400 (2) ◽

pp. 022016 ◽

Cited By ~ 1

Author(s):

Q Ding ◽

S Mohan ◽

T Taen ◽

Y Tsuchiya ◽

Y Nakajima ◽

...

Keyword(s):

Critical Current Density ◽

Critical Current ◽

Current Density ◽

Diffusion Method ◽

Superconducting Tapes ◽

High Critical Current Density

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A high critical current density MOCVD coated conductor with strong vortex pinning centers suitable for very high field use

Superconductor Science and Technology ◽

10.1088/0953-2048/22/5/055013 ◽

2009 ◽

Vol 22 (5) ◽

pp. 055013 ◽

Cited By ~ 30

Author(s):

Z Chen ◽

F Kametani ◽

Y Chen ◽

Y Xie ◽

V Selvamanickam ◽

...

Keyword(s):

Critical Current Density ◽

Critical Current ◽

Current Density ◽

High Field ◽

Vortex Pinning ◽

Coated Conductor ◽

High Critical Current Density ◽

Pinning Centers ◽

Strong Vortex ◽

Very High

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High critical current density in iron-clad MgB2 tapes

Applied Physics Letters ◽

10.1063/1.1582358 ◽

2003 ◽

Vol 82 (23) ◽

pp. 4113-4115 ◽

Cited By ~ 71

Author(s):

H. Fang ◽

S. Padmanabhan ◽

Y. X. Zhou ◽

K. Salama

Keyword(s):

Critical Current Density ◽

Critical Current ◽

Current Density ◽

High Critical Current Density

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Critical current density and microstructure variations in YBa2Cu3O7−x + BaSnO3 films with different concentrations of BaSnO3

Journal of Materials Research ◽

10.1557/jmr.2008.0412 ◽

2008 ◽

Vol 23 (12) ◽

pp. 3363-3369 ◽

Cited By ~ 23

Author(s):

C.V. Varanasi ◽

J. Burke ◽

L. Brunke ◽

H. Wang ◽

J.H. Lee ◽

...

Keyword(s):

Critical Current Density ◽

Critical Current ◽

Current Density ◽

Gradual Increase ◽

Critical Transition ◽

Critical Transition Temperature ◽

Transmission Electron ◽

Order Of Magnitude ◽

High Fields ◽

Magnitude Increase

Previous work on YBa2Cu3O7−x (YBCO) + BaSnO3 (BSO) films with a single composition showed significant critical current density (Jc) improvements at higher fields but lowered Jc in low fields. A detailed study on BSO concentrations provided here demonstrates that significant Jc enhancement can occur even up to 20 mol% BSO inclusion, where typical particulate inclusions in these concentrations degrade the YBCO performance. YBCO + BSO films were processed on (100) LaAlO3 substrates using premixed targets of YBa2Cu3O7-x (YBCO) with additions of 2, 4, 10, and 20 mol% BSO. The critical transition temperature Tc of the films remained high (>87 K), even with large amounts (20 mol%) of BSO. YBCO + BSO films showed a gradual increase in Jc at high fields as the amount of BSO was increased. More than an order of magnitude increase in Jc was measured in YBCO + BSO samples as compared to regular YBCO at 4 T. YBCO + 10 mol% BSO films showed overall improvement at all the field ranges while YBCO + 20 mol% BSO was better only at high fields. Transmission electron microscopy revealed the presence of ∼7–8-nm-diameter BSO nanocolumns, the density of which increased with increasing BSO content correlating well with the observed improvements in Jc.

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