Structural and magnetic properties of La2/3Ca1/3MnO3/LaNiO3 artificial superlattices prepared by rf magnetron sputtering

Magnetic oxide superlattices consisting of ferromagnetic oxide La2/3Ca1/3MnO3 (LCMO) and paramagnetic oxide LaNiO3 (LNO) have been successfully grown on SrTiO3 (STO) substrate by rf magnetron sputtering. Measurements of X-ray reflectivity and high-resolution X-ray diffraction were employed to characterize the microstructure of these films. An azimuthal scan about the surface Bragg peak of the film shows the epitaxial relationship between the film and the substrate. The clearly discernible main feature and satellite features observed in the (002) crystal-truncation-rod indicate the high quality of the LCMO/LNO artificial superlattice structure formed on a SrTiO3 substrate. Hysteresis measurements show magnetic properties to be highly correlated with interfacial strain between the substrate and the film: the smaller is the LNO spacer thickness, the larger is the in-plane lattice strain of the films present, and the larger is the ratio of remnant magnetization to saturation magnetization and the magnetic coercivity field.