SUPERSTRUCTURE AND STRUCTURAL VARIANTS IN SR2CUO2(CO3)

The structure of the compound Sr2CuO2(CO3) has been reexamined by means of electron diffraction and high resolution electron microscopy. It was found that next to the body centered structure, a second variant of the structure, based on a primitive lattice, occurs. The two structural variants differ in the stacking mode of the CO3 layers. The actual crystal contains a mixture of these two stacking modes; the body centered one being predominant. A considerable degree of stacking disorder leading to streaked reflections is found mainly in the crystal parts based on the primitive lattice. Under electron irradiation the carbon-oxygen sublattice is found to disorder. © 1994 Academic Press, Inc.