Effect of current polarity on BSCCO/Ag ceramics textured by Electrically Assisted Laser Floating Zone

Bi-2212/Ag superconducting ceramics were grown using the electrically assisted laser floating zone (EALFZ) technique. The main goal was improving the superconducting properties by applying an electrical current through the sample during the solidification process. The effect of a 100 mA current inte...

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Detalles Bibliográficos
Autores: Costa, F. M., Rasekh, Sh., Ferreira, Nuno M., Sotelo, Andres, Diez, J. C., Madre, M. A.
Tipo de recurso: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2013
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/117550
Acceso en línea:http://hdl.handle.net/10261/117550
Access Level:acceso abierto
Palabra clave:Superconductivity
Critical current
Electrical current
Laser floating zone
Bi-2212
Descripción
Sumario:Bi-2212/Ag superconducting ceramics were grown using the electrically assisted laser floating zone (EALFZ) technique. The main goal was improving the superconducting properties by applying an electrical current through the sample during the solidification process. The effect of a 100 mA current intensities in two configurations were studied: (i) direct current (connecting the seed rod to the positive pole and the feed to the negative one) and (ii) reverse current (positive pole connected to the feed rod and negative to the seed one). The resulting textured cylindrical bars were annealed in order to obtain the superconducting phases. A strong correlation between current polarity, grain alignment and superconducting properties was observed. The rods grown under direct current exhibit higher critical current density (-3000 A/cm2) than the ones grown under conventional method (-2300 A/cm2) or under reverse current condition (-35 A/cm2). The superior value obtained for the direct current results from a better grain alignment and fewer amount of second phases.