Thermoelectric properties of intermetallic semiconducting RuIn3 and metallic IrIn3

Low temperature (<400 K) thermoelectric properties of semiconducting RuIn3 and metallic IrIn3 are reported. RuIn3 is a narrow band gap semiconductor with a large n-type Seebeck coefficient at room temperature ( S ( 290K) approximate to -400 mu V/K), but the thermoelectric figure of merit (ZT(290K) approximate to 0.007) is small because of high electrical resistivity and thermal conductivity (k(290 K) similar to 2.0 W/m K). IrIn3 is a metal (n(290K) approximate to 10(21)cm(-3)) with low thermopower at room temperature (S(290K) approximate to -20 mu V/K). Iridium substitution on the ruthenium site has a dramatic effect on transport properties, which leads to a large improvement in the power factor (S2/p (390K) similar to -207 mu W/mK(2) and corresponding figure of merit (ZT(380K) = 0.053), improving the efficiency of the material by almost an order of magnitude. VC 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4793493]