%0 Journal Article
%A C.J.D Hetherington
%A Ramamoorthy Ramesh
%A M.A O'Keefe
%A R Kilaas
%A G Thomas
%A S.M Green
%A H.L Luo
%B Applied Physics Letters
%D 1988
%G eng
%P 1016-1018
%R 10.1063/1.100074
%T High-resolution electron microscopy of the c=30.5 Å and c=38.2 Å polytypoids in the Bi-Ca-Sr-Cu-O superconductor
%V 53
%X We report results of high-resolution structure imaging, image processing, and simulation of the c=30.5 Å (Tc =80 K) and c=38.2 Å (Tc =115 K) superconducting polytypoids in the Bi-Ca-Sr-Cu-O system. The increase in c parameter is due to the insertion of two layers of Cu-O perovskite+Ca atoms in each unit cell. From the processed image and simulations, it appears that the central Cu layer in the c=38.2 Å polytypoid may be oxygen deficient. In addition, the image simulation experiments suggest that the oxygen atoms in the Bi-O layers are located at the face center of the Bi lattice.