Interdiffusion between SrCuO2 and a glassy precursor. Toward the understanding of the mechanism of formation of Bi based 2223 superconducting bulk ceramics

An interdiffusion couple experiment made between SrCuO2, the best precursor for the 2223 phase formation, and its corresponding glassy partner has been realized in order to investigate the 2223 phase formation mechanism involved in the glassy matrix precursor method. The chemical composition of the zones observed in the sample was determined by energy dispersive X-ray microanalysis. We have also analyzed the successive formation of various phases during the thermal treatment which showed that the glassy compound crystallizes first before reacting with the crystalline precursor, leading to the formation of a Ca4Bi6O13 phase which then reacts with the crystalline precursor to produce the 2201 phase followed by successive formation of 2212 and then 2223 phases.