Large Enhancement of Boron Carbides{close_quote} Seebeck Coefficients through Vibrational Softening

Journal Article · Tue Sep 01 00:00:00 EDT 1998 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.81.2316· OSTI ID:663113

Aselage, T L ^[1]; Emin, D; McCready, S S; Duncan, R V ^[2]

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1. Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States)
2. Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131-1156 (United States)

We report measurements of the Seebeck coefficients of boron carbides having compositions B{sub 12+x}C {sub 3{minus}x} , 0.15{lt}x{lt}1.7 , from 6thinsptothinsp900thinspK. These Seebeck coefficients are large, {approx}200 {mu} V/K at 300thinspK, despite boron carbides having high carrier densities, {approx}10{sup 21} cm{sup {minus}3} . The Seebeck coefficients also have unusual temperature dependencies and depend only weakly on carrier density. These exceptional properties can arise from boron carbides{close_quote} bipolaronic holes substantially softening the vibrational modes with which they interact. {copyright} {ital 1998} {ital The American Physical Society}

• Research Organization: Sandia National Laboratory
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 663113
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 11 Vol. 81; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
BORON CARBIDES
BORON COMPOUNDS
CARBON COMPOUNDS
CARRIER DENSITY
CHEMICAL COMPOSITION
POLARONS
SEEBECK EFFECT
TEMPERATURE DEPENDENCE
THERMOELECTRICITY
VIBRATIONAL STATES