Comparative study of thermoelectric properties of Co based filled antimonide skutterudites with and without SOC effect

In this article we communicate the spin-orbit interaction effects on the thermoelectric properties of alkaline-earth (A = Ca, Sr and Ba) based fully filled skutterudites ACo(4)Sb(12). From the electronic structure calculations for ACo(4)Sb(12) (A = Ca, Sr and Ba) it is understand that spin-orbit coupling take part in splitting of the states of the materials, however in case of BaCo4Sb12, with splitting, the maximum peak around the Fermi level also becomes sharper. This in turn affects the thermal performance of this material. Maximum peak value of Seebeck coefficient is significantly reduced for CaCo4Sb12 and SrCo4Sb12, however in case of BaCo4Sb12 Seebeck coefficient is increased significantly in the lower chemical potential region for n-type doping when spin-orbit coupling is added to the calculations. Furthermore there is also reduction in the electrical and electronic thermal conductivities for all compounds CaCo4Sb12, SrCo4Sb12 and BaCo4Sb12, due to spin-orbit interaction. Maximum zT's values obtained without spin-orbit interaction for CaCo4Sb12, SrCo4Sb12 and BaCo4Sb12 are 0.97, 0.95 and 0.64 whereas with the spin-orbit interaction maximum zT's values are 0.64, 0.59 and 0.69 respectively. (C) 2017 Elsevier B.V. All rights reserved.