Interfacial modulation of hump-like anomalous Hall effect in inhomogeneous SrRuO3 thin films

SrRuO3 (SRO) is a strongly correlated perovskite oxide known for its itinerant ferromagnetism, high electrical conductivity, and strong spin–orbit coupling. In this study, we grew epitaxial SRO (001) thin films on SrTiO3 (001) substrates under different substrate annealing conditions to modulate the film–substrate interface, and we systematically investigated the films’ Hall transport properties. Hall effect measurements reveal that the observed anomalous Hall effect (AHE) in these SRO films arises from an inhomogeneous SRO layer rather than a topological Hall effect (THE) associated with skyrmions. In contrast to previous works limited to ultrathin films, we achieve hump-like AHE anomalies in ∼40 unit-cell-thick SRO by introducing structural inhomogeneities through controlled oxygen annealing. This work breaks the thickness confinement of THE-like responses and provides an alternative interfacial engineering strategy to regulate the AHE characteristics. Our findings shed light on the origin of THE-like behavior in SRO and present a feasible approach for tailoring its electrical transport properties via interface-controlled inhomogeneity.