DEPRESSION OF SUPERCONDUCTIVITY BY TILTING OF THE 6-COORDINATED CUO2 PLANE

Based on the concept of ''interlayer epitaxy'', we considered a correl ation between a Cu-Cu length, a shape of a CuO2 plane and a critical t emperature (Tc) of cuprate oxide superconductors with a 6-coordinated CuO2 plane. When the Cu-Cu length of a layered cuprate was in a range of 3.760 Angstrom-3.805 Angstrom or 3.840 Angstrom-3.880 Angstrom, the CuO2 plane was flat and the cuprate showed superconductivity. When th e Cu-Cu length of the layered cuprate was between 3.805 Angstrom and 3 .840 Angstrom, the CuO2 plane changed into a tilt structure and at the same time the superconductor changed into a semiconductor. These resu lts suggest that the shape of the CuO2 plane including tilting is stro ngly correlated with depression of superconductivity.