Magnetic proximity-mediated Anomalous Hall effect in Pt/WS₂/Fe₃O₄ heterostructures

When a two-dimensional (2D) transition metal dichalcogenide (TMD) is placed in proximity of a magnetic substrate, magnetism in the 2D TMD layer can be induced by the magnetic proximity effect. As a result, the charge and spin transport properties of this heterostructure can be altered by the induced magnetism. In this work, we have systematically investigated the magnetic proximity effect on the temperature dependence of transverse resistivity in Pt(5nm)/WS₂/Fe₃O₄(20nm)/Si heterostructures. Fe₃O₄ has been chosen as the magnetic substrate because its electrical conduction is drastically changed at the Verwey transition (~120 K), at which the system transforms from the high temperature metallic to low temperature insulating state. Chemical vapor deposition (CVD) grown WS₂ monolayers were first wet transferred on the top of the 20nm Fe₃O₄ film and Pt(5nm) was then deposited on the WS₂/Fe₃O₄(20nm)/Si heterostructure by magnetron sputtering. Anomalous Hall effect (AHE) has been observed in both Pt(5nm)/WS₂/Fe₃O₄(20nm)/Si and Pt(5nm)/Fe₃O₄(20nm)/Si heterostructures over a temperature range of 10-300 K. The background-corrected AHE voltage in Pt(5nm)/WS₂/Fe₃O₄(20nm)/Si exhibits a significant change around the Verwey transition, relative to Pt(5nm)/Fe₃O₄(20nm)/Si. The incorporation of the WS₂ monolayers is also found to give rise to the spin transport properties due to the interplay between the induced magnetism and electronic band structure close to the WS₂/Fe₃O₄ interface.