Measurements of switching via spin-orbit coupling mechanisms are discussed for a pair of inverted
Pt/Co/Pt stacks with asymmetrical Pt thicknesses. Taking into account the planar Hall effect
contribution, effective fields of spin-orbit torques (SOT) are evaluated using lock-in measurements
of the first and second harmonics of the Hall voltage. Reversing the stack structure leads to
significant asymmetries in the switching behavior, including clear evidence of a nonlinear current
dependence of the transverse effective field. Our results demonstrate potentially complex interplay
in devices with all-metallic interfaces utilizing SOT.
Copyright (2014) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Appl. Phys. Lett. 104, 012408 (2014) and may be found at http://dx.doi.org/10.1063/1.4861459