THE KINETICS OF THE FORMATION OF THE BI-BASED SUPERCONDUCTING PHASE

Based on the results of X-ray diffraction measurement and the theory o f chemical kinetics, the kinetic curve and equation were established f or the 2201, 2212 and 2223 phase, respectively, in the Bi-based superc onductor. It is elaborated that the three superconducting phases are f ormed by consecutive reactions, and the former is successively the mai n reactant for the latter. The apparent activation energy of an overal l reaction is proved to be the dominant factor controlling the formati on of the superconducting phase. Additionally, the orientation for pre paring high-quality Bi-based superconducting materials is discussed.