A. Gupta, R. Gross, et al.
SPIE Advances in Semiconductors and Superconductors 1990
Crystals of Hg0.5Pb0.5Ba2Ca4Cu5O12+δ were measured on an X-ray four-circle single-crystal diffractometer and the crystal structure was refined to R = 0.033. The onset of the superconducting transition of the crystals ranges from 101 K-115 K. The space group is P4/mmm and lattice parameters of the five-layer material are a = 3.8529(3) Å, and c = 22.172(2) A ̊. Hg is partially substituted for Pb and heavy atoms are shifted away from the origin by ∼0.38 A ̊. Stacking faults of 1234 or 1256 material are manifest in the Fourier maps, and the amount was refined to 4.4%. These stacking faults induce an additional electron density at the ideal O(4) site and mask a possible oxygen occupancy at ( 1 2, 1 2, 0). However, electron density is observed at a distance of 0.6 Å from ( 1 2, 1 2, 0), suggesting a shift of the excess oxygen atom from its ideal position. Bondlengths and distances show systematic changes with increasing number n of CuO2 layers. Changes occur mainly in the rock-salt type layer, whereas the CaCuO2 units remain stable over the whole H-12(n-1)n series. © 1995.
A. Gupta, R. Gross, et al.
SPIE Advances in Semiconductors and Superconductors 1990
David B. Mitzi
Journal of Materials Chemistry
Kafai Lai, Alan E. Rosenbluth, et al.
SPIE Advanced Lithography 2007
Kenneth R. Carter, Robert D. Miller, et al.
Macromolecules