Magnetic perovskites A1-xBxMO3 (M a 3d magnetic ion) are a family of oxides whose properties can vary enormously by doping A, B, x and M. Mixed valence of M is related to the magnetic (ferromagnetic, antiferromagnetic ... ) and electronic (metallic, semiconducting) states.
Close to the Curie temperature transport properties (magnetoresistance, thermal conductivity) are field-dependent. This is related to the effect of spin disorder on transport in a fully spin-polarised conduction band. Our aims are to understand the relation between magnetism and magnetotransport and to produce spin electronic devices from these oxides. Ceramics and thin films will be synthesised and studied. Since these compounds are compatible with other perovskites (HTc superconductors, ferroelectrics) heterostructures will be made using pulsed laser deposition in order to demonstrate spin switching in transistors or tunnelling from ferromagnetic perovskites as a basic element of a new spin electronics.