Thermoelectric properties of Srn+1TinO3n+1 (n=1, 2, 3, ∞) Ruddlesden–Popper Homologous Series

Abstract

The transport properties of Srn+1TinO3n+1 (n = 1, 2, 3, ∞) Ruddlesden–Popper Homologous Series were evaluated using the semi-classical Boltzmann theory as implemented in the BoltzTraP code. Based on the electronic band structure calculations, we have calculated the charge carrier's concentration at 300, 600 and 900 K, and found that the Sr4Ti3O10 compound exhibit the highest charge carrier's concentration along the temperature scale.We also have calculated the electrical conductivity and electronic thermal conductivity at 300, 600 and 900 K, and found that in the vicinity of Fermi level these materials exhibit the minimum value of electrical conductivity and electronic thermal conductivity, which is represent the regions where the investigated materials can give its maximum efficiency. For all compounds the highest value of Seebeck coefficient occurs at 300 K then it decreases with increasing the temperature. We have calculated the power factor (P) at 300, 600 and 900 K, and found that beyond the vicinity of Fermi level these materials exhibit the maximum value of P, which is represent the regions where the investigated materials can give its maximum efficiency. We notice that Sr2TiO4 compound exhibit figure of merit (ZT) equal to unity for p-/n-type between −0.1 and +0.05 μ(eV) at all temperatures, and Sr3Ti2O7 compound exhibit ZT equal to unity for p-/n-type between −0.1 and +0.02 μ(eV). Sr4Ti3O10 exhibit ZT equal to unity for all temperatures in the p-type region, whereas in the n-type region it exhibits a unity at 300 K, 1.1 at 600 K and 1.2 at 900 K. While SrTiO3 exhibit ZT equal to unity for p-/n-type between ∓0.1 μ(eV) at all temperatures.