INFLUENCE OF THE POWDER CHARACTERISTICS ON THE PROPERTIES OF THE BI-BASED SUPERCONDUCTORS

Bi-based ceramic materials with superconducting properties,were prepar ed using the solid stare reaction technique, starring with reactive po wders obtained via oxalate coprecipitation, as well as by the traditio nal powders route. The powder characteristics were evaluated using BET method and transmission electron microscopy (TEM). The stages of the high T-c supeconducting phases formation process were investigated by TG, DTA, XRD and IR methods. The dependence of the electric resistance versus temperature was recorded. The densities of the obtained sample s have been also determined. The results emphasised high reactivity an d shorter reaction times of the ceramic bodies obtained by the copreci pitation method. (C) 1998 Elsevier Science Limited. All rights reserve d.