Quantitative Evaluation of Heating Effect on Dynamical Spin Injection Using CoFeB/Pt/CoFeB Trilayered Film

We have examined a dynamical spin injection in a CoFeB/Pt/CoFeB trilayered structure. Although the contribution of the spin pumping was eliminated by the symmetric spin injection from the upper and lower CoFeB layers, a clear voltage change due to the inverse spin Hall effect has been observed. We find that the observed signal can be quantitatively explained by considering the thermal spin injection due to the heating effect during ferromagnetic resonance (FMR). This innovative demonstration indicates the significant contribution of FMR heating in the dynamical spin injection.