  We study current-induced switching of the N\'eel vector in CoO/Pt bilayers to
understand the underlaying antiferromagnetic switching mechanism. Surprisingly,
we find that for ultra-thin CoO/Pt bilayers electrical pulses along the same
path can lead to an increase or decrease of the spin Hall magnetoresistance
signal, depending on the current density of the pulse. By comparing the results
of these electrical measurements to XMLD-PEEM imaging of the antiferromagnetic
domain structure before and after the application of current pulses, we reveal
the reorientation of the N\'eel vector in ultra-thin CoO(4 nm). This allows us
to determine that even opposite resistance changes can result from a
thermomagnetoelastic switching mechanism. Importantly, our spatially resolved
imaging shows that regions where the current pulses are applied and regions
further away exhibit different switched spin structures, which can be explained
by a spin-orbit torque based switching mechanism that can dominate in very thin
films.
