Abstract
By using the first principles cluster calculation together with the band calculation, we identified that (a) Ru or Rh substitution for Fe and (b) Zr, Nb and Mo substitution for V are presumably useful for decreasing the lattice thermal conductivity without greatly affecting the electron transport properties. The Fe2V1−xZrxAl0.9−xSi0.1+x (x=0, 0.02, 0.04, 0.06, and 0.1) alloys indeed possessed the effective reduction in lattice thermal conductivity with increasing Zr concentration while the Seebeck coefficient showed very weak Zr concentration dependence. The Fe2−yIryV0.9−yTi0.1+yAl (y=0, 0.02, 0.04, 0.06, and 0.1) alloys, on the other hand, possessed drastic reduction of Seebeck coefficient most likely due to the newly introduced Ir 5d states. These experimental facts agree with the present theoretical-prediction, and it was clearly proved that the combinational use of cluster calculation and band calculation is very useful in developing new thermoelectric material.
