Thermopower of R Ba sub 2 Cu sub 3 O sub 7 minus x ( R =Y,Er)

Journal Article · Wed Feb 28 23:00:00 EST 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.41.4002· OSTI ID:7143542

Bhatnagar, A K; Pan, R; Naugle, D G ^[1]; Gilbert, G R; Pandey, R K ^[2]

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1. Physics Department, Texas A M University, College Station, Texas 77843 (USA)
2. Electrical Engineering Department, Texas A M University, College Station, Texas 77843 (USA)

Resistance and absolute thermopower of high-{Tc} oxide superconductors {ital R}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} ({ital R}=Y,Er) synthesized by a hot-press sintering technique have been measured in the temperature range of 4--300 K. Resistive behavior of all samples is found to be metallic. The thermopower for both compositions is positive above the superconducting transition temperature. The thermopower of {ital as}-{ital prepared} ErBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} samples shows a weak temperature dependence with a negative slope near room temperature, which increases in magnitude as {ital T}{sub {ital c}} is approached from above. No strong thermopower peak just above {ital T}{sub {ital c}} has been observed either in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} or ErBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}}. Reannealing of an ErBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} sample at 500 {degree}C for 12 h in flowing oxygen increases the magnitude of the thermoelectric power and the magnitude of its slope without affecting {ital T}{sub {ital c}}. Comparison of the results with available theory indicates that there is no completely satisfactory theory of electrical transport in these superconducting oxides.

• OSTI ID: 7143542
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 41:7; 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
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ERBIUM COMPOUNDS
ERBIUM OXIDES
FABRICATION
LOW TEMPERATURE
MEDIUM TEMPERATURE
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POWER
RARE EARTH COMPOUNDS
SINTERING
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
THERMOELECTRIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES