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 Å and c=7.94 Å. 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 (3d5, S=5/2) and (4d1, S=1/2) with magnetic moments 3.87 and −0.38μB respectively and thus there exists an antiferromagnetic coupling via oxygen between them.

► Pb2FeMoO6 has a body-centered tetragonal (BCT) structure. ► Two axial TM−O distances are slightly larger than four equatorial TM−O distances. ► Half-metallic nature ensures Pb2FeMoO6 a potential application in spintronics. ► Fe3+ and Mo5+ ions are in states 3d5 and 4d1 with magnetic moments 3.87 and −0.38μB. ► Antiferromagnetic coupling between Fe3+ and Mo5+ ions is mediated by O2− ions.