Thermoelectric Properties of Misfit Layered Bismuth-Based Rhodium Oxides, (Bi,Pb)<sub>2</sub>Sr<sub>2</sub>Rh<sub>2</sub>O<sub>y</sub>
- 1 Special Doctoral Program for Green Energy Conversion Science and Technology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi, Japan
- 2 Clean Energy Research Center, University of Yamanashi, Yamanashi, Japan
Abstract
Rhodium oxides, including a misfitlayered structure with alternate stacking of a rock salttype layer and a hexagonal RhO 2 layer, are expected to have good thermoelectric properties. Among them, the thermoelectric properties (electrical conductivity (σ), Seebeck coefficient (S), Figure of merit (ZT) and calculated thermal conductivity (κ) by S, σ, ZT, and absolute temperature (T)) of bismuth-based rhodium oxides ((Bi 1-x ,Pb x ) 2 Sr 2 Rh 2 O y , x = 0 and 0.02, hereafter BSR and BPSR, respectively) were investigated. In comparison with Bi 2 Sr 2 Co 2 O y (BSC) at 700°C, S and κ enhanced (increased S, 110 (BSR) and 105 μV K -1 (BPSR) from 85 μV K -1 (BSC) and decreased κ, 0.32 (BSR) and 0.50 W m -1 K -1 (BPSR) from 1.75 W m -1 K -1 (BSC)), whereas σ decreased (15 (BSR) and 31 S cm -1 (BPSR) from 70 S cm -1 (BSC)). BPSR reached the highest ZT value of 0.067 at 700 ° C, compared to those of 0.056 (BSR) and 0.027 (BSC).
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