Effect of the thermal treatment on the superconductivity behaviour of the YBa₂Cu₃O_7−x phase

Abstract

Thermal treatment of the original superconducting phase YBa₂Cu₃O_7−x in the temperature range of 300–800°C showed a mutual effect of the oxygen stoichiometry, ordering of the oxygen vacancies and microstructure. Two superconducting phases having T_C ≈ 90 K and T_C ≈ 50 K, separated by two-phase coexistence region were found in the samples a quenched down from the respective temperatures.