Ab initio study of the electronic structure of Sr2FeMoO6/SrTiO3 multilayers with Fe deficient interfaces

The electronic structure and the magnetic properties of Sr2FeMoO6/SrTiO3(SFMO/STO) multilayers using the Full Potential Linearized Augmented Plane Wave method are investigated in order to discuss the role played by the Fe deficiency at the interface between SFMO and STO layers. The superlattice cell is built with (i) an STO layer consisting on five atomic layers for which the in plane lattice is taken equal to the one of bulk SFMO, (ii) a bulk-like SFMO layer consisting of seven atomic layers ending with Sr2O2 and (iii) an interfacial atomic layer consisting on FeMoO4 (stoichiometric SFMO layer) or Mo2O4 (Fe deficient SFMO layer). The present calculations show that the interface has a very limited impact on the electronic and magnetic properties for the stoichiometric SFMO layer. On the other hand, the polarization of the evanescent states into the STO layer is strongly reduced and the gap into the majority spin band is recovered only for the most inner FeMoO4 atomic plane of SFMO for the Fe deficient SFMO layer as compared to the other case.