Spin-orbit torque-assisted detection of the canted phase of magnetization in a CoTb-based ferrimagnet

The utilization of ferrimagnets in spintronic applications purportedly offers the potential for high-speed and energy-efficient switching of magnetic states, coupled with their notable stability. This collection of characteristics is commonly observed in ferrimagnetic materials that are in close proximity to states of magnetic or angular momentum compensation. This is owing to the presence of two antiparallel ordered magnetic sublattices that exhibit differing responses to variations in temperature or composition. In the vicinity of the magnetic compensation state, an external field has the capacity to disrupt the collinearity between the sublattices, resulting in the codirectionality of the magnetic projections. The existence of the canted phase has been extensively described theoretically, but its experimental investigation remains limited. Here, a violation of antiferromagnetic ordering is detected through a change in the direction of the effective field induced by the spin-orbital torque, without altering the dominant characteristics of the ferrimagnetic structure. This effect is observed both during external heating of the sample and as a consequence of Joule heating with an increase in the transmitted current. In the examined structure of W/Co70Tb30/Ru, the canted phase region is observed at approximately room temperature and at external fields on the order of 0.1 T. Through macrospin modeling and analytical explanations, a correlation between anisotropy, interlattice exchange interaction, and the presence of the canted phase region is established.