Ba/sub 2-//sub x/La/sub x/YCu/sub 3/O/sub 7//sub +- //sub delta/ perovskite compounds: Crystal chemistry
We report the crystal chemical properties of solid solutions obtained by substitution of lanthanum for barium in the high-T/sub c/ superconductor Ba/sub 2/YCu/sub 3/O/sub 7/. An orthorhombic-to-tetragonal symmetry change occurs at x = 0.4 in Ba/sub 2-//sub x/La/sub x/YCu/sub 3/O/sub 7//sub +- //sub delta/ with the tripled perovskite supercell maintained. Charge compensation is achieved through reduction of the formal copper valence (delta = 0) in the orthorhombic phase and by a mixture of excess oxygen accommodation (delta>0) and formal valence reduction in the tetragonal phase. The resistivity increases by several orders of magnitude, even though the average formal copper valence changes very little.
- Research Organization:
- ATandT Bell Laboratories, Murray Hill, New Jersey 07974-2070
- OSTI ID:
- 5451882
- Journal Information:
- Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 37:10; ISSN PRBMD
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
CHEMICAL PROPERTIES
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
DIFFRACTION
DISPERSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
LATTICE PARAMETERS
MIXTURES
ORTHORHOMBIC LATTICES
OXIDES
OXYGEN COMPOUNDS
PEROVSKITES
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
POWDERS
RARE EARTH COMPOUNDS
SCATTERING
SOLID SOLUTIONS
SOLUTIONS
SUPERCONDUCTORS
TETRAGONAL LATTICES
TRANSITION ELEMENT COMPOUNDS
VALENCE
X-RAY DIFFRACTION
YTTRIUM COMPOUNDS
YTTRIUM OXIDES