Thermoelectric power of high- T sub c superconductors

Journal Article · Mon Apr 30 20:00:00 EDT 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.41.8723· OSTI ID:6883560

Devaux, F; Manthiram, A; Goodenough, J B ^[1]

---

1. Center for Materials Science and Engineering, ETC 5.160, University of Texas at Austin, Austin, Texas 78712 (USA)

Thermoelectric-power measurements are reported for four copper oxide superconductor systems: La{sub 2{minus}{ital y}}Sr{sub {ital y}}CuO{sub 4}, Nd{sub 1+{ital y}}Ba{sub 2{minus}{ital y}}Cu{sub 3}O{sub 6+{ital x}}, Y{sub 0.6}Ca{sub 0.4}Ba{sub 1.6{minus}{ital y}}La{sub 0.4+{ital y}}Cu{sub 3}O{sub 6+{ital x}}, and Bi{sub 2}Sr{sub 2{minus}2{ital y}}La{sub 2{ital y}}CuO{sub 6+{ital x}}. The Seebeck coefficient {alpha} is interpreted in terms of an electron-diffusion component {alpha}{sup {ital e}} that varies from the small-polaron limit for the antiferromagnetic compositions to the metallic limit for the normal-metal compositions. It is argued that the width of the conduction band increases exponentially with oxidation of the CuO{sub 2} sheets. At larger hole doping, the correlation splitting in the superconductor compositions becomes small enough to require the introduction of a two-band model for {alpha}{sup {ital e}}. In those systems in which holes are trapped from the CuO{sub 2} sheets into the inactive'' intergrowth layers, the temperature dependence of {alpha} develops a characteristic maximum at a temperature {ital T}{sub {ital m}}. From a {ital T}{sup {minus}1} dependence for {ital T}{gt}{ital T}{sub {ital m}}, a trapping energy is extracted; this energy increases linearly with the formal charges of the intergrowth layers. The fall in {alpha} with decreasing temperature for {ital T}{lt}{ital T}{sub {ital m}} is interpreted to reflect the consequences of a freezing out of the displacements of the {ital c}-axis oxygen that are associated with charge transfer between the active'' and inactive'' superconductor layers.

• OSTI ID: 6883560
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 41:13; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
BISMUTH COMPOUNDS
BISMUTH OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
CHARGE TRANSPORT
COPPER COMPOUNDS
COPPER OXIDES
ELECTRICAL PROPERTIES
HOLES
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
NEODYMIUM COMPOUNDS
NEODYMIUM OXIDES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POLARONS
QUASI PARTICLES
RARE EARTH COMPOUNDS
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTORS
THERMOELECTRIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TYPE-II SUPERCONDUCTORS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES