Tuning magnetic proximity effect inside CoFe2O4/Pt bilayers by controlling the interface structure

Magnetic proximity effect (MPE) allows magnetic order to be introduced into an intrinsically non-magnetic system by placing it adjacent to a ferromagnet. Thus, using MPE from a ferromagnetic insulator is a promising approach to manipulate spin currents inside adjacent 2D materials. In this study, we demonstrate the influence of interface structure on MPE inside ferrimagnetic insulator CoFe$_{\mathrm{2}}$O$_{\mathrm{4}}$/non-magnet Pt bilayers. Molecular beam epitaxy was used to grow high quality CoFe$_{\mathrm{2}}$O$_{\mathrm{4}}$ thin films and control the termination layer which came into contact with Pt. Subsequent resistivity and Hall measurements show that the strength of MPE inside Pt depends on which if the two possible termination layers of CoFe$_{\mathrm{2}}$O$_{\mathrm{4}}$ comes into contact with the Pt atoms.