Author(s)

Takuya Watanabe¹, Hiroshi Irie^1,2*

¹Special Doctoral Program for Green Energy Conversion Science and Technology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi, Japan.
²Clean Energy Research Center, University of Yamanashi, Yamanashi, Japan.

Rhodium oxides, including a misfitlayered structure with alternate stacking of a rock salttype layer and a hexagonal RhO₂ 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) ₂Sr₂Rh₂O_y, x = 0 and 0.02, hereafter BSR and BPSR, respectively) were investigated. In comparison with Bi₂Sr₂Co₂O_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).

Electroceramics, Layered Rhodium Oxide, Misfit Layer Structure, Thermoe-lectric Material, Harman Method

Watanabe, T. and Irie, H. (2018) Thermoelectric Properties of Misfit Layered Bismuth-Based Rhodium Oxides, (Bi,Pb)₂Sr₂Rh₂O_y. Journal of Materials Science and Chemical Engineering, 6, 97-103. doi: 10.4236/msce.2018.67011.