Magnetic proximity-induced magnetoresistance in Pt/Tm₃Fe₅O₁₂ heterostructures

Thin Pt films on magnetic garnet exhibit ferromagnetic-like transport properties, which may affect the functionality of Pt in spin current detection, although direct observation of this effect has not been made. Here, we report the observation of a magnetic proximity-induced magnetoresistance (MP-MR) in Pt/Tm₃Fe₅O₁₂ (TmIG) heterostructures. This electrical signal is directly correlated with the itinerant ferromagnetism induced by the magnetic proximity effect (MPE) at the Pt/TmIG interface. The existence of MP-MR has been unambiguously verified through the insertion of a Cu interlayer and supported by quantitative analysis, which also enables clear differentiation from the spin Hall magnetoresistance (SMR) signal. The weak ferromagnetism observed in Pt follows the typical behavior of itinerant ferromagnetism, as predicted by the Stoner criterion. By utilizing TmIG films with enhanced perpendicular magnetic anisotropy (PMA), we achieve amplification of the MP-MR effect. Our results demonstrate that the magnitude of MP-MR increases with decreasing temperature. Moreover, the strength of MP-MR can be substantially enhanced through improved PMA in TmIG. These findings underscore the potential of MPE-based magnetotransport phenomena for advancing spintronic device applications.