Effect of water vapor and low-temperature decomposition on the structure and electrophysical properties of nonstoichiometric compound Ba2YCu3O7 − δ

Abstract

The effect of water vapor and decomposition into phases with different oxygen contents on the structure and electrophysical properties of the nonstoichiometric compound Ba2YCu3O7 − δ has been studied. Both these factors were shown to lead to the formation of structural defects that can be pinning centers and improve the current-carrying capacity of materials. At the same time, the reaction with water leads to a deterioration of superconducting properties of grain boundaries. The optimum electrophysical properties of Ba2YCu3O7 − δ can be reached by choosing appropriate heat-treatment conditions, namely, the temperature and time of annealing and the water-vapor content in the annealing atmosphere. The phase diagram of the Ba2YCu3O6-Ba2YCu3O7 system below 400°C is refined.