  Current induced magnetization switching by spin-orbit torques offers an
energy-efficient means of writing information in heavy metal/ferromagnet (FM)
multilayer systems. The relative contributions of field-like torques and
damping-like torques to the magnetization switching induced by the electrical
current are still under debate. Here, we describe a device based on a symmetric
Pt/FM/Pt structure, in which we demonstrate a strong damping-like torque from
the spin Hall effect and unmeasurable field-like torque from Rashba effect. The
spin-orbit effective fields due to the spin Hall effect were investigated
quantitatively and were found to be consistent with the switching effective
fields after accounting for the switching current reduction due to thermal
fluctuations from the current pulse. A non-linear dependence of deterministic
switching of average Mz on the in-plane magnetic field was revealed, which
could be explained and understood by micromagnetic simulation.
