ELECTRON DOPING EFFECTS ON ELECTRONIC AND MAGNETIC PROPERTIES IN Sr2FeReO6

We have investigated the electronic and magnetic properties of electron-doped Sr2-xLaxFeReO6 (x = 0.0, 0.25, 0.5) using first-principles density functional theory within the generalized gradient approximation (GGA) and GGA + U schemes. Our results reveal that the symmetry of the La-doped compounds is decreased from tetragonal I4/m for perfect sample to monoclinic P21/n. With increasing La content the absolute magnetic moment of the Re site increases distinctly and the doped electrons are considered to occupy mainly the down-spin Re 5d band from the band calculation. Electronic doping is found to enhance the Curie temperature (Tc) and stabilize the ferromagnetic half-metallic ground states of Sr2FeReO6. And it is found that the increase of Tc is mainly caused by the increase of ferromagnetic interaction between the Fe–O–Fe.