Magnetic order and valency at La0.7Sr0.3MnO3/SrTiO3 interfaces

We have performed first principles calculations of the electronic properties and the magnetic order at the interface of La0.7Sr0.3MnO3 and SrTiO3. The results are analysed in order to give the strength of the exchange between the surface MnO2 layer and the bulk and also the degree of the polarization of the bands. It is shown that these properties depend on the way the interface is grown. Two different interface terminations are identified and modelled. The results of the calculations compare favourably with recent experimental data.