2017 年 81 巻 2 号 p. 55-59
Thermoelectric(TE) power generation can directly convert waste heat into electric energy. However, one of the bottlenecks for widespread use of TE power generation is toxicity of currently-used TE materials. We focused on Al-based materials as candidate of low-toxicity TE materials. Although Al-based materials have high power factor, the achievement of high TE performance is difficult because of the high lattice thermal conductivity. The aims of the present study are to synthesize Al5Co2 known as a pseudogap intermetallic compound, and to investigate the TE properties. We found that lattice thermal conductivity κlat of Al5Co2 is lower than those of other Al based TE materials, such as Fe2VAl, Al2Ru and Al3V. The κlat of Al5Co2 at room temperature was 7.1 Wm-1K-1. We also found that Fe substitution at Co sites enhances power factor(PF). The maximum PF was ~0.6 mWm-1K-2 at room temperature for Al5(Co0.95Fe0.05)2.