Sol–gel chemistry approach in the preparation of precursors for the substituted superconducting oxides

Abstract Sol–gel processing of ceramic materials for advanced applications involves several steps starting from precursor synthesis and ending up with multicomponent metal oxides. A simple sol–gel synthesis technique has been refined to prepare the precursors for the superconducting (Y1−xScx)Ba2Cu4O8 and (Y1−xGax)Ba2Cu4O8 compounds. The amorphous gel powders were characterized by powder X-ray diffraction, infrared spectroscopy, thermal analysis and elemental analysis. A systematic characterization of precursor gels led us to predict the approximate composition and the chemical reactions involved during gelation. The stability and high level of homogeneity obtained for the gels make them suitable as processable precursors to substituted (Y1−xScx)Ba2Cu4O8 and (Y1−xGax)Ba2Cu4O8 superconducting compounds.