Structure and composition in the superconductive Bi--Sr--Ca--Cu--O system

Journal Article · Tue Nov 01 04:00:00 EST 1988 · J. Mat. Res.; (United States)

DOI:https://doi.org/10.1557/JMR.1988.1317· OSTI ID:6749241

Carim, A H; Kentgens, A P.M.; Hengst, J H.T.; de Leeuw, D M; Mutsaers, C A.H.A.

Characterization of superconducting Bi--Sr--Ca--Cu oxides has been carried out by electrical measurements, x-ray diffraction, conventional and high-resolution electron microscopy, and electron microprobe analysis. Nominal starting compositions with cation ratios of 1:1:1:2 and 2:2:1:2 show considerably different superconducting behavior. In both cases multiphase materials are formed. The predominant superconducting phase occurs as thin platelets with an orthorhombic, modulated structure. These particles often have edges aligned along (110), (100), and (010) directions and contain subgrain boundaries. Electron diffraction patterns and high-resolution micrographs taken along several zone axes are consistent with an incommensurate centered modulation along the b axis with a magnitude of 4.7 +- 0.1 times b. Unexpectedly, two distinct chemical compositions were found in platelets with the same apparent structure: Bi/sub 4/Sr/sub 3/Ca/sub 3/Cu/sub 4/O/sub 16//sub +- //sub delta/ for the lower T/sub c/ phase in the 1:1:1:2 material, and Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8//sub +- //sub delta/ for the isomorphic higher T/sub c/ phase present in the 2:2:1:2 samples.

• Research Organization: Philips Research Laboratories, P. O. Box 80.000, 5600 JA Eindhoven, The Netherlands
• OSTI ID: 6749241
• Journal Information: J. Mat. Res.; (United States), Journal Name: J. Mat. Res.; (United States) Vol. 3:6; ISSN JMREE
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BISMUTH COMPOUNDS
BISMUTH OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PELLETS
PHYSICAL PROPERTIES
SAMPLE PREPARATION
SCATTERING
STOICHIOMETRY
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
X-RAY DIFFRACTION