Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5367590 | Applied Surface Science | 2009 | 4 Pages |
Superconducting polycrystalline BSCCO fibers of 2:2:1:2 nominal composition were grown by the electrically assisted laser floating zone (EALFZ) technique. An electric current density of 2.1Â AÂ cmâ2 was applied through the solid/liquid (S/L) interface. A net effect of the fiber diameter on the as-grown microstructure and on the final superconducting properties is observed. A higher critical current density (â¼2520Â AÂ cmâ2) results for the thinner fibers (ÏÂ =Â 1.7Â mm) comparing to the value (â¼1065Â AÂ cmâ2) found for the wider ones (ÏÂ =Â 2.5Â mm). The steep axial thermal gradient at the S/L interface in the thinner fibers is responsible for its superior texture degree, a crucial parameter for improved current transport properties. Moreover, a Cu-free Bix(Sr,Ca)yOz phase crystallizes preferentially from the melt in the wider fibers, acting as obstacles to the current flux.