We have succeeded in the preparation of a broad set of epitaxial Sr2FeMoO6 thin films by pulsed laser deposition. We have studied the effect of various deposition conditions, on both substrate-induced strain and antisite disorder (ASD), which translate into a variety of magnetic and transport properties of the films. We find that the saturation magnetization and the magnetoresistance are dominated by the degree of cationic order, and the strain effects are clearly evidenced in a lower TC. We characterize the ASD induced magnetoresistance, which arises from a moderate concentration of antisite defects and vanishes for massive ASD levels.

In the strive to find a straightforward method for determining the spin polarization, the analysis of the Andreev reflection process in point contact junctions has attracted much interest. However, the prerequisite for an evaluation of the transport spin polarization in this scheme is the existence of elastic (ballistic or diffusive) transport, which cannot be assumed a priori. We therefore also include inelastic processes in our analysis and exemplify that thermal effects can have a significant effect on data evaluation. As ferromagnetic samples with a predicted half metallic behavior and comparably low conductivity we used thin films of the double perovskite Sr2FeMoO6 and bulk material of the Heusler compound Co2Cr0.6Fe0.4Al

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