Pb-for-Bi substitution for enhancing thermoelectric characteristics of (Bi, Pb)(2)Ba2O4 +/-omega (0.5)CoO2
Journal
Applied Physics Letters
Journal Volume
88
Journal Issue
23
Date Issued
2006
Author(s)
Abstract
We report strongly enhanced thermoelectric characteristics for a misfit-layered oxide, [Bi2Ba2O4±ω]0.5CoO2, in a wide temperature range, as achieved through substituting up to 20% of Bi by Pb. The Pb substitution kept the thermal conductivity (κ) unchanged but decreased the electrical resistivity (ρ) and increased the Seebeck coefficient (S) simultaneously, such that a three-fold enhancement in the thermoelectric figure of merit, Z (≡S2∕ρκ), was realized. At the same time x-ray absorption near-edge structure data indicated that the valence and spin states of Co are not affected by the Pb-for-Bi substitution.
Type
journal article