Authors: Y Takagiwa Y Matsuura K Kimura
Publish Date: 2014/01/30
Volume: 43, Issue: 6, Pages: 2206-2211
Abstract
We have focused on the binary narrowbandgap intermetallic compounds FeGa3 and RuGa3 as thermoelectric materials Their crystal structure is FeGa3type tetragonal P42/mnm with 16 atoms per unit cell Despite their simple crystal structure their room temperature thermal conductivity is in the range 4–5–W–m−1–K−1 Both compounds have narrowbandgaps of approximately 03–eV near the Fermi level Because their Seebeck coefficients are quite large negative values in the range 350––S 373K––550–μV–K−1 for undoped samples it should be possible to obtain highly efficient thermoelectric materials both by adjusting the carrier concentration and by reducing the thermal conductivity Here we report the effects of doping on the thermoelectric properties of FeGa3 and RuGa3 as n and ptype materials The dimensionless figure of merit ZT was significantly improved by substitution of Sn for Ga in FeGa3 electrondoping and by substitution of Zn for Ga in RuGa3 holedoping mainly as a result of optimization of the electronic part S 2 σ
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