Half-metallic ferromagnetic nature of the double perovskite Pb2FeMoO6 from first-principle calculations

The structural, electronic and magnetic properties of the double perovskite Pb2FeMoO6 have been studied by using the first-principle projector augmented wave (PAW) potential within the generalized gradient approximation (GGA) as well as taking into account the on-site Coulomb repulsive interaction (GGA+U). Similar to Sr2FeMoO6 and Pb2FeReO6, the optimized crystal structure of Pb2FeMoO6 is a body-centered tetragonal (BCT) with the lattice constants a=b=5.60 angstrom and c=7.94 angstrom. The two axial TM-O distances are slightly larger than the four equatorial TM-O distances, which shows that the Jahn-Teller structural distortion exists in FeO6 and MoO6 octahedra. The half-metallic ferromagnetic nature implies a potential application of this new compound in spintronics devices. The Fe3+ and Mo5+ ions are in the states (3d(5), S=5/2) and (4d(1), S=1/2) with magnetic moments 3.87 and -0.38 mu(B) respectively and thus there exists an antiferromagnetic coupling via oxygen between them. (C) 2012 Elsevier Ltd. All rights reserved.