Interfacial Magnetic Coupling In Co/Antiferromagnetic Van Der Waals Compound Feps3

In this study, a Co-thin film was deposited on the van der Waals compound of FePS3 for the investigation of interfacial magnetic coupling, which is crucial to the application in spintronic devices. As characterized by atomic force microscopy, the exfoliated FePS3 surface was composed of defects within +/- 1 monolayer height. The Co thin film covered the FePS3 substrate uniformly with a roughness within +/- 0.5 nm. The 2 nm-Pd/7 nm-Co/FePS3 exhibited isotropic magnetism in the surface plane and the magnetic coercivity drastically decreased by more than 50% when the temperature was elevated from 85 K to 110-120 K, which is nearly the Neel temperature of FePS3 . This observation indicates the interfacial magnetic coupling between Co and FePS3 . The Co/FePS3 magnetic coupling is robust even after annealing up to 200 degrees C. Furthermore, the measurement of X-ray magnetic circular dichroism confirmed the presence of non-compensated Fe moment along the inplane direction is parallel to the Co magnetization direction. The net Fe-moment is supposed to play an essential role in mediating the magnetic coupling between the in-plane ferromagnetic Co and the perpendicular antiferromagnetic FePS3.