Electronic Structure and Thermoelectric Properties of Pseudogap Intermetallic Compound Al 5 Co 2

Abstract

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 dif - ficult because of the high lattice thermal conductivity. The aims of the present study are to synthesize Al 5 Co 2 known as a pseudogap intermetallic compound, and to investigate the TE properties. We found that lattice thermal conductivity κ lat of Al 5 Co 2 is lower than those of other Al based TE materials, such as Fe 2 VAl, Al 2 Ru and Al 3 V. The κ lat of Al 5 Co 2 at room temperature was 7 . 1 Wm ︲ 1 K ︲ 1 . We also found that Fe substitution at Co sites enhances power factor （ PF ） . The maximum PF was ～ 0 . 6 mWm ︲ 1 K ︲ 2 at room temperature for Al 5 （ Co 0 . 95 Fe 0 . 05 ） 2 . ［ doi:10 . 2320 / jinstmet.J2016053 ］ （ 2016 ）