Spin-flop coupling at $L{a}_{0.5}S{r}_{0.5}\mathrm{Fe}{O}_3/L{a}_{0.7}S{r}_{0.3}\mathrm{Mn}{O}_3$ interfaces

Antiferromagnetic (AFM) spintronics offer several benefits compared to their ferromagnetic (FM) counterparts, such as high storage capacity and faster processing speed, however, difficulties in manipulating and detecting the AFM moments impede their implementation. Spin-flop coupling, the interfacial perpendicular coupling between FM and AFM moments, can be utilized to control the orientation of AFM moments with the application of moderate magnetic fields on the scale of tenths of a Tesla. In this work, epitaxial bilayers of AFM $L{a}_{0.5}S{r}_{0.5}\mathrm{Fe}{O}_3$ (LSFO)/FM $L{a}_{0.7}S{r}_{0.3}\mathrm{Mn}{O}_3$ (LSMO) with fixed LSMO thickness ($\sim 85$ u.c.) and LSFO thicknesses varying from 10 to 50 u.c. were investigated to determine the effect of Sr doping and $L{a}_{1-x}S{r}_x\mathrm{Fe}{O}_3$ magnetocrystalline anisotropy on the strength of spin-flop coupling. X-ray magnetic linear dichroism demonstrated that the spin-flop coupling strength decreased with increasing LSFO layer thickness, persisting at a thickness of 50 u.c. ($\sim 20$ nm). Furthermore, photoemission electron microscopy revealed a domain-by-domain correlation between the FM and AFM domains consistent with the perpendicular orientation dictated by spin-flop coupling. These results demonstrate that LSFO/LSMO bilayers have the potential to serve as a model materials system for AFM spin transport measurements.