We have prepared polycrystalline samples of Yb-Nb-S-based misfit-layered compound and measured their thermoelectric properties below 300 K. The compound consists of an alternate stacking of a trigonal prism (MoS2)-type [NbS2] layer and a two-layered rock-salt-type [Yb 1.90S2] slab, being incommensurate parallel to the a-axis. Approximately 5% Yb deficiency is necessary to obtain single-phase samples. Metallic conductivity accompanied by a large Seebeck coefficient S has been observed down to 4.2 K for the single-phase samples. At 300K, the sample exhibits S = 60 μV·K-1 and resistivity of p = 1.4mΩ·cm, with thermal conductivity of κ = 0.80 W·K-1·m-1. The resulting figure-of-merit (Z = S2/ρκ) becomes 3.2 × 10-4 K-1 at 300K, yielding the dimensionless figure-of-merit of ZT ∼ 0.1.
|ジャーナル||Japanese Journal of Applied Physics, Part 2: Letters|
|出版ステータス||Published - 2004 9 15|
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)
- Physics and Astronomy(all)