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Textured Bi 2 Ca 2 Co 1.7 O x ceramic rods were obtained by Electrically Assisted Laser Floating Zone (EALFZ) technique. The polarity effects of an external current, applied during the laser floating zone growth, have been investigated.Microstructure and thermoelectric properties have been studied and correlated with the current polarity. An important improvement of power factor was obtained for samples grown with the positive pole connected to the seed. This result evidences the advantages of EALFZ technique as a potential method for obtaining high performance thermoelectric materials.

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The efforts of carrying forward superconducting materials to commercialization can be overcome by materials with high performance potentiated by a suitable processing technique. In this work, extreme critical currents up to 241 A @ 77 K were attained by tuning the crystal growth in a directional solidification process. Bulk rods of textured Bi-2212/2.9 wt % Ag were obtained by changing the conventional laser floating zone technique through the application of a d.c. electrical current during the crystallization process. Using an optimized composition, the electrically assisted laser floating zone (EALFZ) allowed obtaining 5800 A/cm 2 in rods exhibiting only 2.3 mm in diameter, the highest value reported so far for bulk samples. This behavior is a consequence of the texture enhancement and radial phase distribution, exceeding a 2-fold increase in J c compared with samples grown without electrical current. Morphological and structural observations are discussed and correlated with the results from the electrical characterization. Applications on extremely efficient electrical current leads working at temperatures below 77 K using the abovedescribed materials grown by EALFZ are anticipated.