Direct Imaging of Current-Induced Antiferromagnetic Switching Revealing a Pure Thermomagnetoelastic Switching Mechanism in NiO

We unravel the origin of current-induced magnetic switching of insulating antiferromagnet/heavy metal systems. We utilize concurrent transport and magneto-optical measurements to image the switching of antiferromagnetic domains in specially engineered devices of NiO/Pt bilayers. Different electrical pulsing and device geometries reveal different final states of the switching with respect to the current direction. We can explain these through simulations of the temperature-induced strain, and we identify the thermomagnetoelastic switching mechanism combined with thermal excitations as the origin, in which the final state is defined by the strain distributions and heat is required to switch the antiferromagnetic domains. We show that such a potentially very versatile noncontact mechanism can explain the previously reported contradicting observations of the switching final state, which were attributed to spin-orbit torque mechanisms.

Automated summary

Researchers have unraveled the mechanism of current-induced magnetic switching in insulating antiferromagnet/heavy metal systems using concurrent transport and magneto-optical measurements. Different final states of the switching in specially engineered NiO/Pt bilayers devices were observed with different electrical pulsing and device geometries, attributed to the thermomagnetoelastic switching mechanism combined with thermal excitations. This noncontact mechanism provides a potential explanation for previously reported contradicting observations of switching final state attributed to spin-orbit torque mechanisms.