  The manipulation of magnetization via Magnetic torques is one of the most
important phenomena in spintronics. In thin films, conventionally, a charge
current flowing in a heavy metal is used to generate transverse spin currents
and to exert torques on the magnetization of an adjacent ferromagnetic thin
film layer. Here, in contrast to the typically employed heavy metals, we study
spin-to-charge conversion in ferromagnetic heterostructures with large
spin-orbit interaction that function as the torque-generating layers. In
particular, we chose perpendicular magnetic anisotropy (PMA) multilayers
[Co/Ni] and [Co/Pt] as the torque-generating layers and drive magnetization
dynamics in metallic ferromagnetic thin film $\mathrm{Co_{20}Fe_{60}B_{20}}$
(CoFeB) layers with in-plane magnetic anisotropy (IMA). We investigate the spin
dynamics driven by spin-orbit torque (SOT) and the concomitant charge current
generation by the inverse SOT process using an inductive technique based on a
vector network analyzer. In our experimental findings, we find that the SOTs
generated by our multilayers are of a magnitude comparable to those produced by
Pt, consistent with first-principles calculations. Furthermore, we noted a
significant correlation between the SOT and the thickness of the CoFeB layer.
