First-principles study of magnetic and thermoelectric properties of SnFe2O4 and SnCo2O4 spinels

In this article, the physical properties of SnFe2O4 and SnCo2O4 have been investigated by means of the full-potential linearized augmented-plane-wave method within Density functional theory and semiclassical Boltzmann transport theory. Calculations of the electronic and magnetic properties are executed by using the WIEN2k code whereas the BoltzTraP code is used to calculate the thermoelectric properties. Calculations of the spin-polarized band structures (BS) and density of states (DOS) illustrated the studied materials as half-metallic in nature. Analysis of the energetic stability of ferromagnetic (FM) and antiferromagnetic (AFM) states revealed the FM state as the stable ground state for these materials. The exchange energies, John-Teller energy and hybridization ensure the origin of ferromagnetism in these compounds is associated with electron spin rather than Fe2+ and Co2+ clustering. Furthermore, we comprehensively investigated the spin polarization and Curie temperature of these compounds. Investigations of the thermoelectric properties indicated that the electrical and thermal conductivity ratio fits the Wiedmann Franz law. The thermoelectric power factors and figures-of-merit demonstrated appropriate thermoelectric efficiency of the studied compounds.