Three-dimensional ferromagnetism and magnetotransport in van der Waals Mn-intercalated tantalum disufide

Van der Waals (vdW) ferromagnets are an important class of materials for spintronics applications. The recent discovery of atomically vdW magnets CrI₃ and Cr₂Ge₂Te₆ has triggered a renaissance in the area of two-dimensional (2D) magnetism. Herein we systematically studied 2H-Mn0.28TaS₂ single crystal, a 2D vdW ferromagnet with Tc~82.30.16em0exK, and a large in-plane magnetic anisotropy. Mn K-edge x-ray absorption spectroscopy was measured to provide information on its electronic state and local atomic environment. The detailed magnetic isotherms measured in the vicinity of Tc indicates that the spin coupling inside 2H-Mn0.28TaS₂ is of a 3D Heisenberg type coupled with the attractive long-range interaction between spins that decay as J(r)≈r^-4.85. Both resistivity ρ(T) and thermopower $S(T)$ exhibit anomalies near Tc, confirming that the hole-type transport carriers strongly interact with local moments. An unusual angle-dependent magnetoresistance is further observed, suggesting a possible field-induced novel magnetic structure.