Enhanced superconducting properties in Li-doped BPSCCO high-Tc ceramics

Superconductors are currently used only in low scale applications where other materials cannot compete with their unique properties. High-Tc superconductors are highly processing sensitive and, therefore, prohibitively expensive at this time. A new technique, Field-Assisted-Sintering Technique (FAST), is proposed for superconductors to shorten the processing time. It combines the use of an external electrical field with pressure application at a high heating rate, thus making the processing time less than 15 min. We have applied this method to the decomposition of the precursor powders with different starting cations in Bi-Pb-Sr(Ba)-Ca-Cu-O system. In some compositions LiI has been added. Enhanced formation of Bi2Sr2Ca2Cu3Ox phase in Ba-substituted BPSCCO ceramics was observed in FAST-treated and post-annealed samples. All compositions have high density depending on starting composition. (authors)