Electronic, thermoelectric and magnetic properties of La2NiMnO6 and La2CoMnO6

Effect of spin polarization on the electronic and thermoelectric properties of double pervoskites La2NiMnO6 and La2CoMnO6 are studied using the full-potential linearized augmented plane wave method. Further magnetic properties of the compound are also determined. Both compounds are indirect bandgap ferromagnetic materials. La2NiMnO6 compound has a large band gap energy as compared to La2CoMnO6 compound in both spin up and spin down states. The electrical conductivity, thermal conductivity and thermoelectric power increase with temperature for both the compounds in the spin up state, while the spin down state unchanged with the increase of temperature. There is no significant variation observed in Seebeck coefficient S with temperature for spin up state while the Seebeck coefficient decrease with the increase of temperature in both compounds for spin down state. The calculated total magnetic moments for both compounds reveals the strong ferromagnetic nature.