PEROVSKITE OXIDE SUPERLATTICES - MAGNETOTRANSPORT AND MAGNETIC-PROPERTIES

We have fabricated perovskite superlattices consisting of two ferromag netic metallic oxides: La0.67Ca0.33MnO3 (LCMO) and SrRuO3 (SRO). We ha ve investigated the magnetotransport and magnetic properties of a seri es of samples. in which the layer thickness of LCMO is tired and that of SRO varied from 0 to 20 unit cells. The magnetoresistance ratio in a superlattice can be increased by a factor of 3 at low temperatures o ver the MR ratio in pure LCMO film. This substantial enhancement is mo st likely caused by the interface spin-dependent scattering. The super lattice structure also increases T-c of LCMO by introducing a biaxial tension, and induces two consecutive switchings of magnetic easy axis direction with increasing SRO thickness.