Effect of partial substitution of calcium for yttrium on the structure and properties of the Y sub(0.9)Ca sub(0.1)Ba sub(2)Cu sub(3)O sub(6.8) superconductor

The crystal structure of the high-temperature Y sub(1-x)Ca sub(x) Ba sub(2)Cu sub(3)O sub(6.8) superconductor has been studied in a temperature range of 80-300 K using low-temperature X-ray diffraction analysis; its microstructure has been studied by scanning and transmission electron microscopy. Changes of the bond length in the structure of principal phase and precipitation topology of impurity phases and their compositions have been analyzed. An addition of calcium was shown to increase the environmental tolerance of the principal Y123 phase and its microhardness and ensures the low unchanged coefficient of thermal expansion. All of the facts indicate that the material can be used to manufacture composite superconducting articles.