resumo
The new electrical assisted laser floating zone (EALFZ) technique was used to grow superconducting fibres of Bi2Sr2CaCu2O8 (2212-BSCCO). The application of an electrical current through the crystallization interface proved to advantageously modify the phase nature and texture of 2212-BSCCO polycrystalline fibres compared to conventionally laser floating zone (LFZ) grown ones. The current application during the growth induces a selective and more intense ionic migration along the fibre axis. As a result, an increase in superconducting phase fraction and a decrease of residual melt were observed together with grain alignment intensification. The main outcome in the superconducting properties is the improvement of the critical current density at 77 K, from 1.2 x 10(3) A/cm(2), in the LFZ fibres, to 2.8 x 10(3) A/cm(2), in the EALFZ processed ones. (C) 2010 Elsevier B. V. All rights reserved.
palavras-chave
CRITICAL-CURRENT DENSITIES; SOLIDIFICATION
categoria
Chemistry; Materials Science; Physics
autores
Carrasco, MF; Amaral, VS; Silva, RF; Costa, FM
nossos autores
Rui Ramos Ferreira e Silva
Professor associado
Vitor Brás Sequeira Amaral
Professor CatedráticoGrupos
2 - nanoestruturas e cerâmicos ferróicos multifuncionais
3 - materiais de carbono, compósitos e revestimentos funcionais
agradecimentos
The financial funding from the FCT Project PTDC/CTM/66195/2006 is gratefully acknowledged by the authors.