The kinetics of the formation of the Bi-based superconducting phase

Abstract Based on the results of X-ray diffraction measurement and the theory of chemical kinetics, the kinetic curve and equation were established for the 2201, 2212 and 2223 phase, respectively, in the Bi-based superconductor. It is elaborated that the three superconducting phases are formed by consecutive reactions, and the former is successively the main reactant for the latter. The apparent activation energy of an overall reaction is proved to be the dominant factor controlling the formation of the superconducting phase. Additionally, the orientation for preparing high-quality Bi-based superconduting materials is discussed.