Understanding the Seebeck coefficient of LaNiO 3 compound in the temperature range 300-620 K

Transition metal oxides have been attracted much attention in thermoelectric community from the last few decades. In the present work, we have synthesized LaNiO by a simple solution combustion process. To analyse the crystal structure and structural parameters we have used Rietveld refinement method wherein FullProf software is employed. The room temperature x-ray diffraction indicates the rhombohedral structure with space groupR3¯c(No. 167). The refined values of lattice parameters are = = = 5.4071 Å. Temperature dependent Seebeck coefficient ( ) of this compound has been investigated by using experimental and computational tools. The measurement of is conducted in the temperature range 300-620 K. The measured values of in the entire temperature range have negative sign that indicates n-type character of the compound. The value of is found to be ∼-8 V/K at 300 K and at 620 K this value is ∼-12 V/K. The electronic structure calculation is carried out using DFT + method due to having strong correlation in LaNiO . The calculation predicts the metallic ground state of the compound. Temperature dependent is calculated using BoltzTraP package and compared with experiment. The best matching between experimental and calculated values of is observed when self-interaction correction is employed as double counting correction in spin-polarized DFT + (=1 eV) calculation. Based on the computational results maximum power factors are also calculated for p-type and n-type doping of this compound.