Oxygen content, microstructure and Tc variation of La1.84Sr0.16CuOy

Abstract Thermodynamic measurements of equilibrium oxygen partial pressure (P O 2 ) as a function of oxygen content at 1173K have been performed on La 1.84 Sr 0.16 CuO y . These measurements confirmed the presence of traces of an impurity phase of the type La 8− x Sr x Cu 8 O 20 (an oxygen-deficient, perovskite structure) which is always present in sintered La 2− x Sr x CuO y type oxides. Samples of La 1.84 Sr 0.16 CuO y with controlled oxygen content were prepared taking into account the amount of oxygen related to this impurity phase. The superconducting properties of these samples were studied through ac susceptibility and a correlation where T c decreases as the oxygen content decreases was found.