抄録
The high-temperature thermoelectric (TE) properties of group 13 elements (Ga, In, and Tl) triple-filled skutterudites in the nominal compositions of InxGa0.02Tl0.20Co4Sb12 (0 ≤ x ≤ 0.30) were investigated. All samples contained impurity phases in addition to the skutterudite matrix phase, i.e. some of the filler elements added to CoSb3 precipitated as the metal state and antimonides. With increase the starting amount of In, the actual content of In increases while that of Tl decreases. Owing to phonon scattering by rattling of the group 13 elements, low lattice thermal conductivity was achieved, leading to relatively high TE figure of merit (ZT) for all samples. The maximum ZT value was 0.72 at 773 K obtained for the sample in the nominal composition of In0.30Ga0.02Tl0.20Co4Sb12.
