Electronic properties of Sm_xSr_(1-x)MnO_3 for solid oxide fuel cell application - a first-principles study

摘要

Electronic properties of orthorhombic SSM (Sm0.5Sr0.5MnO3) and monoclinic SSM (Sm0.8Sr0.2MnO3) are investigated using the first-principles calculation. The half-metallic behavior that leads to the mixed ionic and electronic conductivity (MIEC) property is identified in orthorhombic SSM. In addition, the strong covalent bonding between Mn-p and O-s orbitals of orthorhombic SSM is identified from the PDOS plot. The strong covalent bonding enhances the O-2 molecular adsorption on Mn atom. On the other hand, monoclinic SSM shows the pure conducting behavior and there is no covalent bonding between Mn and O atoms. Thus, the results suggest that the half-metal Sm0.5Sr0.5MnO3 might be a suitable cathode material for intermediate-temperature solid oxide fuel cells.