Studies on structural characteristics of high Tc superconducting BiCaSrCuO phases

Abstract

The recently discovered high Tc superconducting BiCaSrCuO phases show several structural subtilities. In the present investigation evidences and arguments have been advanced to show that the modified perovskite phase with a=b= √2 ap results and the modulated superstructural phase owe their origin to the loss of Ca and Sr atoms respectively. The present investigation also reveals that structural phases with higher periodicities e.g. ∼48 Å, 54 Å, etc. which may correspond to very high Tc e.g. 190 K and higher do really exist in the BCSCO system. © 1988.