Angular dependence of the ferromagnetic resonance and remanent magnetization of exchange-couple LSMO/LNO/LSMO trilayered structures

J. C. ROJAS SÁNCHEZ; M. GRANADA; J. MILANO; L.B. STEREN

S. C. de Bariloche

Conferencia; 13th International Conference on Solid Films and Surfaces; 2006

In this work we present a study of trilayers consisting of two ferromagnetic layers La0.75Sr0.25MnO3 (LSMO), exchange-coupled through a nonmagnetic spacer layer LaNiO3 (LNO). The study of the exchange coupling between LSMO layers has been made in LSMO/LNO/LSMO trilayers with different LNO spacer thickness, by ferromagnetic resonance (FMR) at 9.5GHz. The angular dependence of the resonance field has been measured with the dc magnetic field applied in the plane of the films at 130K. The experiments results have been analysed in terms of the free energy density of the samples, including cubic magnetocrystalline, uniaxial and shape anisotropy and Zeeman energy for the single LSMO layers, studied as references. We have found 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 film in the ferromagnetic layers (LSMO). In the trilayered structures, moreover, we have also added a term taking into account the interlayer coupling between the top and bottom LSMO electrodes.