Conductivities and Seebeck Coefficients of Boron Carbides: ''Softening-Bipolaron'' Hopping

Journal Article · Thu Jul 20 00:00:00 EDT 2000 · Physical Review B

OSTI ID:759968

ASELAGE, TERRENCE L ^[1]; EMIN, DAVID JACOB; MCCREADY, STEVEN S

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1. Sandia National Laboratories

The most conspicuous feature of boron carbides' electronic transport properties is their having both high carrier densities and large Seebeck coefficients. The magnitudes and temperature dependencies of the Seebeck coefficients are consistent with large contributions from softening bipolarons: singlet bipolarons whose stabilization is significantly affected by their softening of local vibrations. Boron carbides' high carrier densities, small activation energies for hopping ({approx} 0.16 eV), and anomalously large Seebeck coefficients combine with their low, glass-like thermal conductivities to make them unexpectedly efficient high-temperature thermoelectrics.

• Research Organization: Sandia National Labs., Albuquerque, NM (US); Sandia National Labs., Livermore, CA (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 759968
• Report Number(s): SAND2000-1772J
• Journal Information: Physical Review B, Journal Name: Physical Review B
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON CARBIDES
SEEBECK EFFECT
STABILIZATION
THERMAL CONDUCTIVITY