Physicochemical studies of semiproducts and superconductive ceramics based on complex rare earth, barium and copper oxides

Multistage character and temperature range of superconducting phase formation on the basis of complexes oxides of rare earths, barium and copper are ascertained, intermediate compound of possible composition Ln2BaCuO5 is identified. On the basis of data of element X-ray fluorescence analysis it is shown that in superconducting samples of ceramics and initial mixture both bi- and trivalent copper is present