Structural and magnetic properties of La0.75Sr0.25MnO3/ LaNiO3 superlattice

ROJAS SÁNCHEZ, J.C.; GRANADA, M.; AND STEREN, L.B.

Buenos Aires, Argentina

Workshop; At the Frontiers of Condensed Matter III; 2006

In this work we present a study of the structural and magnetic properties of La0:75Sr0:25MnO3/LaNiO3 (LSMO/LNO) multilayers. With this purpose, we have grown [LSMOt1/LNOt2]n multilayers on crystalline (100) SrTiO3 (STO) substrates by dc sputtering. The superlattices consist on n bilayers LSMO/LNO being t1 and t2 the thicknesses of LSMO and LNO, respectively. We performed a morphological and structural characterization of the samples by X-ray diffraction spectroscopy (XRD). We found that the LSMO and LNO layers grow textured in the [100] direction. The surface´s roughness of the samples has been studied by Atomic Force Microscopy (AFM). The roughness at the interfaces, the lattice parameters of the lms and layer´s thicknesses (t1 and t2) of the superlattices, were determined by tting the theta-2theta XRD patterns at high-angles considering the kinematical model in the Suprex program [1]. The angular dependence of the remanent magnetization was measured at different temperatures in order to deduce the anisotropies of the samples. The experimental data were analyzed assuming a free energy density of the samples that includes cubic magnetocrystalline anisotropy, uniaxial and shape anisotropies deduced for the single LSMO layers studied as references. The results for ferromagnetic LSMO layers show a cubic magnetocrystalline anisotropy (Kcub<0) and a uniaxial anisotropy oriented along one of the crystalline axes of the perovskite structure in the plane of the lm [2]. We also studied the shape of the magnetization loops for different LNO´s thickness t2.