Perovskite oxide superlattices: Magnetotransport and magnetic properties

We have fabricated perovskite superlattices consisting of two ferromagnetic metallic oxides: (Formula presented)(Formula presented)Mn(Formula presented) (LCMO) and SrRu(Formula presented) (SRO). We have investigated the magnetotransport and magnetic properties of a series of samples, in which the layer thickness of LCMO is fixed 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 over the MR ratio in pure LCMO film. This substantial enhancement is most likely caused by the interface spin-dependent scattering. The superlattice structure also increases (Formula presented) of LCMO by introducing a biaxial tension, and induces two consecutive switchings of magnetic easy axis direction with increasing SRO thickness. © 1996 The American Physical Society.