Revealing the Role of Anisotropy in Neel Vector Switching of a Platinum/ Hematite Heterostructure*

It has been observed that in heavy metal/antiferromagnetic insulator bilayers such as Pt/α-Fe2O3, a DC current in the Pt can induce a change in the magnetic state of the antiferromagnetic insulator. These bilayers are an active area of research due to their potential for fast, efficient, and high-density magnetic memory. However, the relative contributions of the different mechanisms behind this change of magnetic state are still unclear. In order to further understand the competing switching mechanisms and inherent anisotropy in these heterostructures we perform angular transport measurements. The remnant spin-magnetoresistance allows us to probe the in-plane anisotropies of the α-Fe2O3 films, revealing an extrinsic growth induced uniaxial anisotropy which is affected by substrate choice and film growth parameters. In addition, by changing the device geometry we are able to characterize the effect of Joule heating induced anisotropic strain on the switched magnetic state.