High-T_c superconductivity in perovskite-type oxides

The concept leading to the discovery of a class of new superconductors will be described. Superconductive and structural properties of both, the La2CuO4-based (40 K) and the RE-Ba-Cu-O-based (90 K) superconductors are discussed. Experiments showing the influence of oxygen deficiency and microstructure on these properties will also be presented. © 1987.