Structural, electronic and magnetic properties of the double perovskite Pb _2FeReO _6

摘要

The structural, electronic and magnetic properties of the double perovskite Pb _2FeReO _6 have been studied by using the first-principles projector augmented wave (PAW) potential within the generalized gradient approximation (GGA) as well as taking into account the on-site Coulomb repulsive and exchange coupling interactions (GGAU). The optimized crystal structure of the Pb _2FeReO _6 is a body-centered tetragonal (BCT) with a space group of I4/m and the lattice constants of a=b=5.59 ? and c=7.93 ?, consistent with the experimental results. The two axial transition metal and oxygen (TM-O) distances are slightly larger than the four equatorial TM-O distances and shows the existence of the Jahn-Teller structural distortion in FeO _6 and ReO _6 octahedra. The Fe ~(3+) and Re ~5 ions are in the states (3d ~5, S=5/2) and (5d ~2, S=1) with magnetic moments 3.929 and -0.831μ B respectively and thus antiferromagnetic (AFM) coupling via oxygen between them. The half-metallic (HM) ferromagnetic (FM) nature implies a potential application of this new compound in magnetoelectronic and spintronics devices.