Epitaxially-induced perpendicular anisotropy in manganite films

Summary form only given. La/sub 0.7/Sr/sub 0.3/MnO/sub 3/ is a good model system to study several fundamental aspects of spin transport. It is claimed to be fully polarised at E/sub F/ and the absence of an s-character band gives 100% 3d-symmetry electrons. As it is a member of the perovskite family, it is possible to grow epitaxial heterostructures based on manganites and insulating perovskite layers such as SrTiO/sub 3/ to form tunnel junctions. Though the main characteristics of spin-tunnelling are known, the details of the effect is not yet clear. The role of the barrier, which can hybridise with the electrodes, the role of the carrier symmetry (s or d) and the voltage and temperature dependence of the tunnel magnetoresistance are to be understood. In particular, the rapid disappearance of the spin tunnelling effect in manganite junctions is not understood. Here we focus on one aspect of manganite heterostructures, which is the role of epitaxial strain on the electrode magnetism.