%0 Journal Article
%K High temperature superconductors
%K Superconducting materials
%K Magnetic properties
%K Lattice parameters
%K Oxide superconductors
%K Microscopic Examination–Transmission Electron Microscopy
%K Ceramic Materials–Electric Conductivity
%K Lead Compounds–Electric Conductivity
%K Lead Metallography–Microstructures
%K Diamagnetic Properties
%K Lead Strontium Calcium Erbium Copper Oxides
%K Low Temperature Properties
%A Ramamoorthy Ramesh
%A E Wang
%A L.H Greene
%A M.S Hegde
%A J.-M Tarascon
%B Journal of Materials Research
%D 1990
%G eng
%P 251-257
%R 10.1557/JMR.1990.0251
%T Electron Microscopy of the Pb-Sr-Ca-Er-Cu-O Superconductor
%V 5
%X The structure and microstructure of a solid state processed Pb-Sr-Ca-Er-Cu-O superconductor have been investigated by transmission electron microscopy. In addition to the majority superconducting phase, at least two other impurity phases have been observed. The superconducting phase is a layered structure similar to the Bi2Sr2CaCu2Cycompound, with an extra Cu atom between the two PbO layers. Stacking defects inside the grain have been observed. A grain boundary amorphous phase has also been observed. The steps in the resistivity-temperature plot and the consequent absence of Tc, 0 above 8 K are attributed to either the presence of the Pb2Sr2Cu2Oyunit cell at the grain boundary and/or a local enrichment of oxygen at the grain boundaries. Superlattice spots in the [100] zone axis diffraction patterns from regions enriched in Ca and Er with respect to the nominal composition are interpreted as due to ordering of Sr and Ca/Er in the Sr sites. © 1990, Materials Research Society. All rights reserved.