Browsing by Author "Silva, E. F."

Now showing 1 - 4 of 4
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    Longitudinal spin Seebeck effect and anomalous Nernst effect in CoFeB/non-magnetic metal bilayers
    (2021) Gamino, M.; Santos, J. G. S.; Souza, A. L. R.; Melo, A. S.; Della Pace, R. D.; Silva, E. F.; Oliveira, A. B.; Rodriguez-Suarez, R. L.; Bohn, F.; Correa, M. A.
    We investigate the longitudinal spin Seebeck effect in CoFeB/NM bilayers, with Ta, Pd and Ru as non-magnetic NM material. By means of a quantitative approach using an equivalent circuit model, we determine the accurate voltage due inverse spin Hall effect measured in the non-magnetic layer beyond unveiling the role of anomalous Nernst effect and thermoeletric effects provide by metallic ferromagnetic CoFeB layer. From experimental results, we estimate the spin Seebeck coefficient for the bilayers, finding values quite compatible with those for ferromagnetic insulators reported in literature. Moreover, we address the angular dependence of the voltage curves, disclosing the non-magnetic layer affects the effective magnetic anisotropy of the whole bilayer. Hence, our results suggest the effective magnetic anisotropy may be modified to improve the thermoelectric voltage response in ferromagnetic/non-magnetic metal bilayers.
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    Spin pumping contribution to the magnetization damping in Tm3Fe5O12/W bilayers
    (2022) Oliveira, A. B.; Rodriguez-Suarez, R. L.; Vilela-Leao, L. H.; Vilela, G. L. S.; Gamino, M.; Silva, E. F.; Bohn, F.; Correa, M. A.; Moodera, J. S.; Chesman, C.
    In this work, thulium iron garnet (Tm3Fe5O12 - TmIG (20 nm)/Tungsten(W)(t) bilayers, sputtered on top of gadolinium gallium garnet (111) substrate, were used to investigate spin pumping (SP) line broadening mechanism in Ferromagnetic Resonance (FMR). The TmIG, films prior and after tungsten cap layer deposition, were investigated employing FMR and X-ray diffraction techniques. The TmIG films showed (1 1 1) orientation and perpendicular magnetic anisotropy (PMA). Due to the interface TmIG/W, when the TmIG magnetization is in resonance a spin current is pumped out the TmIG into the W layer, increasing the damping of the magnetization. Measuring the out-of-plane angular dependence of the FMR resonance field and linewidth, we were able to obtain solely the SP contribution to the line broadening, filtering Gilbert, mosaicity, and two magnon scattering mechanisms.
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    The role of metallic nanoparticles in the enhancement of the spin Hall magnetoresistance in YIG/Pt thin films
    (2018) Gamino, M.; Silva, E. F.; Alves Santos, O.; Mendes, J. B. S.; Rodriguez-Suarez, R. L.; Machado, F. L. A.; Azevedo, A.; Rezende, S. M.
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    Thickness dependence of the magnetic anisotropy and dynamic magnetic response of ferromagnetic NiFe films
    (2017) Silva, E. F.; Corrêa, M. A.; Della Pace, R. D.; Plá Cid, C. C.; Kern, P. R.; Carara, M.; Chesman, C.; Alves Santos, O.; Rodríguez Suárez, Roberto; Azevedo, A.; Rezende, S. M.; Bohn, F.