Bi-based superconductors obtained by oxalate coprecipitation, containing Fe

This paper reports the influence of the substitutional effect of Fe for Cu on the formation mechanism and structure of the superconducting phases in t he Bi-Sr-Ca-Cu-O system. A wet chemical technique - the oxalate coprecipita tion - was used, which offers the possibility of a close control of the che mical and physical characteristics of superconducting powders. The supercon ducting phases formation process was characterized by DTA/TG analysis aid X -ray diffraction, Mossbauer spectra measurements were realized on the Fe-do ped samples. On the samples thermally treated the ceramic properties were d etermined.