New preparative methods to enhance phase purity and physical properties of cuprate superconductors

摘要

Several methods which avoid the problems inherent in solid state reactions have been developed. These methods include freeze drying, liquid ammonia based processes and a novel xerogel process. They are applicable to both 123, 124 and BISCCO based superconductors and have as their goal the atomic mixing of precursors in order to reduce inhomogeneity in the final product. The three methods are described and compared to each other and to conventional methods of synthesis. The products prepared by these methods are fully characterized by elemental analysis, XRD, TGA, DSC, resistivity and magnetic susceptibility versus temperature and by SEM. 13 refs., 2 figs.