Chemistry and high Tc superconductivity in the La-Ba-Cu-O system. Technical report No. 32, 1 July 1987-15 July 1988
A systematic investigation of the chemistry and superconductivity in the La-Ba-Cu-O system was carried out, using x-ray powder diffraction, resistivity and TGA measurements. A phase diagram for the La-Ba-Cu-O quasi-ternary system at 950 C was determined, and the relationship between the phases in this system is discussed. A series of A-cation (ABO/sub 3/-type perovskite) deficient compounds of the type of (LaBa/sub 2/)xCu/sub 3/O/sub 7.0/ (0.67 < x < 0.96) were prepared. Cation deficiencies appear to stabilize the structure but depress Tc. Partial substitution of La and Ba in LaBa/sub 2/CuO(7+delta) by other rare earth and alkali earth cations, respectively, were also investigated. An enhancement in Tc, compared with La1+xBa/sub 2/-xCu/sub 3/O(7+delta) was found in LaBa/sub 2/-xCaxCu/sub 3/O(7+delta) (0 < x , 1.0), providing further evidence for the importance of reduced lattice dimensions in stabilizing the superconducting phase of La-123.
- Research Organization:
- Rutgers--the State Univ., New Brunswick, NJ (USA). Dept. of Chemistry
- OSTI ID:
- 6663050
- Report Number(s):
- AD-A-197175/3/XAB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CATIONS
CHALCOGENIDES
CHARGED PARTICLES
CHEMISTRY
COPPER COMPOUNDS
CUPRATES
DIAGRAMS
DOCUMENT TYPES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
IONS
LANTHANUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHASE DIAGRAMS
PHYSICAL PROPERTIES
POWDERS
PROGRESS REPORT
RARE EARTH COMPOUNDS
SUPERCONDUCTIVITY
TRANSITION ELEMENT COMPOUNDS