Structure and composition in the superconductive Bi--Sr--Ca--Cu--O system
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), Vol. 3:6
- Country of Publication:
- United States
- Language:
- English
Similar Records
Crystal structure of Bi{sub 6}Sr{sub 8{minus}x}Ca{sub 3+x}O{sub 22} ({minus}0.5 {le} x {le} 1.7): A mixed valence bismuth oxide related to perovskite
I. Synthesis, modification and characterization of BiSr-CaCuO[sub x] single crystal superconductors. II. Synthesis and characterization of one dimensional rutheniumtetrammine-pyrazine polymers
Related Subjects
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BISMUTH OXIDES
CRYSTAL STRUCTURE
SUPERCONDUCTIVITY
CALCIUM OXIDES
COPPER OXIDES
STRONTIUM OXIDES
ELECTRON MICROSCOPY
PELLETS
SAMPLE PREPARATION
STOICHIOMETRY
TRANSITION TEMPERATURE
X-RAY DIFFRACTION
ALKALINE EARTH METAL COMPOUNDS
BISMUTH COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
COHERENT SCATTERING
COPPER COMPOUNDS
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SCATTERING
STRONTIUM COMPOUNDS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties
656100 - Condensed Matter Physics- Superconductivity