Abstract
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 Bi2Sr2CaCu2Oy compound, with an extra Cu atom between the two PbO layers. Stacking defects inside the grain have been observed. A grain boundary amorphous phase has been observed. The steps in the resistivity-temperature plot and the absence of Tc,0 above 8 K are attributed to either the presence of the Pb2Sr2Cu2Oy unit 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 due to ordering of Sr and Ca/Er in the Sr sites.
Original language | English (US) |
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Pages (from-to) | 251-257 |
Number of pages | 7 |
Journal | Journal of Materials Research |
Volume | 5 |
Issue number | 2 |
DOIs | |
State | Published - Feb 1990 |
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering