Thermoelectric Properties for a Suspended Microribbon of Quasi-One-Dimensional TiS3

Transition-metal trichalcogenides MX 3 (M = Ti, Zr, Nb, Ta; X = S, Se) are well-known inorganic quasi-one-dimensional conductors. Among them, we have investigated the thermoelectric properties of titanium trisulfide TiS 3 microribbon. The electrical resistivity ρ , thermal conductivity κ , and thermoelectric power S were measured using 3 ω method. The weight mean values were found to be ρ = 5 mω m and κ = 10 W K −1 m −1 along the one-dimensional direction ( b -axis) of the TiS 3 microribbon. Combined with the thermoelectric power S = −530 μ V K −1 , the figure of merit was calculated as ZT = 0.0023. This efficiency is the same as that of randomly oriented bulk TiS 3 . We also estimated the anisotropy of σ and κ using the present results and those for randomly oriented bulk material. The obtained weak anisotropy for TiS 3 is attributable to strong coupling between triangular columns consisting of TiS 3 units. These experimental results are consistent with theoretical results obtained using density functional theory (DFT) calculations.