Anisotropic thermopower in the a - b plane of an untwinned YBa sub 2 Cu sub 3 O sub 7 minus. delta. crystal

Journal Article · Thu Oct 31 23:00:00 EST 1991 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.44.9757· OSTI ID:6222969

Lowe, A J; Regan, S; Howson, M A ^[1]

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1. Department of Physics, University of Leeds, Leeds LS2 9JT (United Kingdom)

We have measured the thermopower of an untwinned crystal of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} in both the {ital a} and {ital b} directions. In the {ital a} direction the thermopower is about +0.7 {mu}V/K just above {ital T}{sub {ital c}}, while in the {ital b} direction the thermopower is opposite in sign and {minus}6 {mu}V/K. The sharp peak observed at {ital T}{sub {ital c}} in twinned crystals is only clearly present in the {ital a}-axis measurement. At temperatures close to room temperature the {ital a}-axis thermopower becomes temperature independent and very small. It is argued that the peak is evidence of superconducting fluctuation effects in the thermopower.

• OSTI ID: 6222969
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 44:17; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
ANISOTROPY
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRYSTALS
ELECTRICAL PROPERTIES
FLUCTUATIONS
HIGH-TC SUPERCONDUCTORS
LOW TEMPERATURE
MONOCRYSTALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
THERMOELECTRIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TWINNING
VARIATIONS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES