Vanishing of superconductivity at a transition from itinerant-electron to small-polaron conduction in nominal Bi/sub 4-//sub x/Pb/sub x/(Sr/sub 3/Ca)Ca/sub 2-//sub x/Y/sub x/Cu/sub 4/O/sub 16/
Lead was found to substitute for bismuth on cosubstitution of yttrium for calcium in nominal Bi/sub 4/(Sr/sub 3/Ca)Ca/sub 2/Cu/sub 4/O/sub 16/. Variations with x in the lattice parameters, the oxidation parameter determined by iodometric titration, and the temperature dependence of resistance have revealed a correlation of the variation of T/sub c/ and c parameter versus x with a metal-to-semiconductor transition. It is argued that this correlation manifests a transition from itinerant-electron to small-polaron conduction. This conclusion is related to the observed shifts in c-axis oxygen that appear to be associated with a transition from antiferromagnetic semiconductor to a superconductor in other copper-oxide systems.
- Research Organization:
- Center for Materials Science and Engineering, ETC 5.160, The University of Texas at Austin, Austin, Texas 78712-1084
- OSTI ID:
- 6619494
- Journal Information:
- Appl. Phys. Lett.; (United States), Vol. 53:26
- Country of Publication:
- United States
- Language:
- English
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75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BISMUTH OXIDES
POLARONS
SUPERCONDUCTIVITY
TRANSITION TEMPERATURE
CALCIUM OXIDES
COPPER OXIDES
LEAD OXIDES
STRONTIUM OXIDES
YTTRIUM OXIDES
EXPERIMENTAL DATA
LATTICE PARAMETERS
LOW TEMPERATURE
ALKALINE EARTH METAL COMPOUNDS
BISMUTH COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
DATA
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
INFORMATION
LEAD COMPOUNDS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
QUASI PARTICLES
STRONTIUM COMPOUNDS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties
656100 - Condensed Matter Physics- Superconductivity