OXYGEN DEFICIENCY δ AND ITS EFFECT ON Tc IN SUPERCONDUCTING Y1Ba2 Cu3O7-δ K. Iguchi, Y. Soga, K. Ando, T. Saito, K. Shinagawa and T. Tsushima J. Phys. Colloques, 49 C8 (1988) C8-2197-C8-2198 DOI: 10.1051/jphyscol:19888986