Exfoliation and van der Waals heterostructure assembly of intercalated ferromagnet Cr _1/3 TaS ₂

Abstract Ferromagnetic van der Waals (vdW) materials are in demand for spintronic devices with all-two-dimensional-materials heterostructures. Here, we demonstrate mechanical exfoliation of magnetic-atom-intercalated transition metal dichalcogenide Cr _1/3 TaS ₂ from its bulk crystal; previously such intercalated materials were thought difficult to exfoliate. Magnetotransport in exfoliated tens-of-nanometres-thick flakes revealed ferromagnetic ordering below its Curie temperature T _C ~ 110 K as well as strong in-plane magnetic anisotropy; these are identical to its bulk properties. Further, van der Waals heterostructure assembly of Cr _1/3 TaS ₂ with another intercalated ferromagnet Fe _1/4 TaS ₂ is demonstrated using a dry-transfer method. The fabricated heterojunction composed of Cr _1/3 TaS ₂ and Fe _1/4 TaS ₂ with a native Ta ₂ O ₅ oxide tunnel barrier in between exhibits tunnel magnetoresistance (TMR), revealing possible spin injection and detection with these exfoliatable ferromagnetic materials through the vdW junction.