Routes to obtain high performance, high Tc superconducting bulk materials
Résumé
This paper reviews our investigations for understanding the fundamental relations between physical properties, crystal chemistry, phases relation and processings on the compounds YBa2Cu3O7−x and Bi(Pb)2Sr2Ca2Cu3O10+x. These two systems have in common the complexity of their crystal structure and multi-components chemistry which require challenging material processing for applications. In the YBaCuO system, horizontal bridgman and melting zone processes have demonstrated the possibility of obtaining high performances in this system, with different shaping. A high reproducibility with low material losses have been achieved with a top seeding melt texturing process. For BiSSCO based compounds, sol–gel and polymer matrix methods have been studied and developed with the achievement of promising critical current densities at 77 K.