Magnetic anisotropy plays an important role in ultrathin structures and two-dimensional materials and influences their magnetoresistance (MR) response. Here, the effects of the two-dimensional WS2 layer on the structural and magnetic properties of cobalt (Co) thin film are investigated in a Co/WS2 bilayer fabricated on Si (100) substrates. The Co layer grown on the WS2 layer formed a crystal structure whereas that individual Co isolated layer is amorphous. Both prepared samples show an out-of-plane easy axis while their in-plane anisotropy is different. The magnetic hysteresis loop and MR measurements show that there is an in-plane easy axis in the Co/WS2 bilayer due to the crystallinity formation of Co grown on WS2 which is not observed in Co isolated layer. Our results represent an interface control of anisotropy in two dimensional structures.

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The photo-induced Hall effect is shown in the Co/WS2 heterostructure. This heterostructure consists of a ferromagnetic metal layer that forms a Schottky junction to a transition metal dichalcogenide semiconductor layer. In this effect, under the magnetic field and light irradiation, the excited charge carriers from the WS2 layer diffuse into the Co layer and are driven by Lorentz forces, then creates a transverse voltage in the open circuit. This open circuit voltage is a function of light and magnetic field intensity. The photo-induced voltage is nonlinear and hysteretic with the applied magnetic field and is in good agreement with magneto-optical Kerr's hysteresis loops. The observed results can provide a new technique for optical and magnetic sensing applications. In addition, it proposed a new technique to reconstruct the in-plane magnetic hysteresis loop for metallic thin films.