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 ${\mathrm{CrI}}_{3}$ and ${\mathrm{Cr}}_{2}{\mathrm{Ge}}_{2}{\mathrm{Te}}_{6}$ has triggered a renaissance in the area of two-dimensional (2D) magnetism. Herein we systematically studied 2H-${\mathrm{Mn}}_{0.28}{\mathrm{TaS}}_{2}$ single crystal, a 2D vdW ferromagnet with ${T}_{c}\ensuremath{\sim}82.3\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, 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 ${T}_{c}$ indicates that the spin coupling inside 2H-${\mathrm{Mn}}_{0.28}{\mathrm{TaS}}_{2}$ is of a 3D Heisenberg type coupled with the attractive long-range interaction between spins that decay as $J(r)\ensuremath{\approx}{r}^{\ensuremath{-}4.85}$. Both resistivity $\ensuremath{\rho}(T)$ and thermopower $S(T)$ exhibit anomalies near ${T}_{c}$, 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.