Thermoelectric Properties of $R_{1-x}$Sr$_{x}$CoO$_{3}$ Perovskites

ORAL

Abstract

Cobalt oxide materials have recently shown promise for use in thermoelectric applications due to enhancement of the Seebeck coefficient ($S)$ by the spin and orbital degeneracy of the Co$^{3+}$ and Co$^{4+}$ ions. We have studied Sr substituted $R$CoO$_{3}$ ($R$ = rare earth elements) perovskites that exhibit increased transition temperatures to the low-spin ground state, which is required for achieving enhanced $S$. We have found that Gd is the smallest $R$ for which the homogenous Sr substitution is possible. We will present structural and thermoelectric properties of these materials with 0 $< \quad x \quad <$ 0.5. We will describe our search for materials with optimal degeneracy ratios, which are stable within practical operating temperature ranges for thermoelectric applications.

*Work supported by NSF Grant No. DMR-0706610.

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Authors

  • S. Boona

    • Physics Department, Northern Illinois University, DeKalb, IL 60115

  • B. Dabrowski

    • MSD, Argonne National Laboratory, and Physics, Northern Illinois University, De Kalb IL, USA
    • Physics Department, Northern Illinois University, DeKalb, IL 60115
    • Physics Department, Northern Illinois University, DeKalb, IL 60115 and Materials Science Division, Argonne National Laboratory, Argonne, IL 60439
    • Department of Physics, Northern Illinois University, DeKalb, IL and Materials Science Division, Argonne National Laboratory, Argonne, IL
    • Northern Illinois University
    • Physics Department, Northern Illinois University, DeKalb IL 60115
    • Department of Physics, Northern Illinois University, DeKalb, IL 60115

  • S. Kolesnik

    • Physics Department, Northern Illinois University, DeKalb, IL 60115
    • Department of Physics, Northern Illinois University, DeKalb, IL and Materials Science Division, Argonne National Laboratory, Argonne, IL
    • Physics Department, Northern Illinois University, DeKalb IL 60115
    • Department of Physics, Northern Illinois University, DeKalb, IL 60115

  • O. Chmaissem

    • MSD, Argonne National Laboratory, and Physics, Northern Illinois University, De Kalb IL, USA
    • Physics Department, Northern Illinois University, DeKalb, IL 60115
    • Physics Department, Northern Illinois University, DeKalb, IL 60115 and Materials Science Division, Argonne National Laboratory, Argonne, IL 60439
    • Department of Physics, Northern Illinois University, DeKalb, IL and Materials Science Division, Argonne National Laboratory, Argonne, IL
    • Department of Physics, Northern Illinois University, DeKalb, IL 60115