Share

Critical currents up to 71,000 A/cm2 at 77 K in melt textured YBCO doped with barium-tin-oxygen(3).

Author(s) : LEPROPRE M., MONOT I., DELAMARE M. P., HERVIEU M., SIMON C., PROVOST J., DESGARDIN G., RAVEAU B., BARBUT J. M., BOURGAULT D., BRAITHWAITE D.

Type of article: Article

Summary

Transport values at 77 K as high as 71,000 A/cm2 in zero field and 11,000 A/cm2 at 20 T have been obtained. A systematic study of this ceramic has been carried out. A textured microstructure is observed, characterized by rather regular striation corresponding to platelet-like 123 grains. Large 211 (green phase) inclusions of about 10 micrometers in diameter are also observed, as well as smaller inclusions which correspond to barium-tin-oxygen(3) (lower than 1 micrometer) at the grain boundaries of the platelets or wrapped in the matrix. It has been found that transport critical-current density data are distributed over a very wide range. Nevertheless, magnetic critical-current density measurements suggest that cracks of the order of micrometres may appear in some regions of the material leading to a dramatic decrease in critical-current densities for the corresponding sample. On the other hand, observations demonstrate that extended defects such as intergrowth or disordering, as well as twin boundaries, cannot be considered to be the major factors for vortex pinning in the textured 123 material. The presence or absence of inhomogeneity on the nanoscale does not seem to influence the critical-current density. It has been determined that pinning is more probably due to microstructure.

Details

  • Original title: Critical currents up to 71,000 A/cm2 at 77 K in melt textured YBCO doped with barium-tin-oxygen(3).
  • Record ID : 1994-3368
  • Languages: English
  • Source: Cryogenics - vol. 34 - n. 1
  • Publication date: 1994/01

Links


See other articles in this issue (10)
See the source

Indexing