Observed high-resolution images of a new high-Tcsuperconductor based on the Bi-Ca-Sr-Cu-O system (Tcabove 70 K) indicated a structure derived from the Bi4Ti3O12type in whichdoubled bismuth oxide layers alternate with double perovskite layers along the c-axis. The orthorhombic unit cell dimensions showed an approximate relation of a=√2apb=5√2apand c=8apwhere ap=3.82 Å, the cell parameter of a cubic perovskite. At least a quarter of the oxygen should be deleted in accordance with the average copper valence of less than 3 and two-dimensional Cu-O layers are supposed to be responsible for the high-Tcsuperconductivity.
ASJC Scopus subject areas
- Physics and Astronomy(all)