Enhanced Anisotropic Magnetic Order and Nonlinear Hall Response in Fe_1/2.5TaS₂

Magnetic intercalation in transition metal dichalcogenides enables robust ferromagnetism with chiral spin textures and topological transport in van der Waals materials. In this work, we present a single crystal Fe_xTaS₂ (x ≈ 0.4) exhibiting T_C = 54 K (∼20 K above the prototype x = 0.33 phase), enabled by enhanced Dzyaloshinskii–Moriya interaction (DMI) from higher intercalation without loss of crystal quality. Magnetization and heat capacity measurements confirm long-range Ising-type ferromagnetic order, with clear perpendicular magnetic anisotropy. X-ray magnetic circular dichroism uncovers a large unquenched orbital magnetic moment on Fe sites, driving a colossal magnetic anisotropy ratio of 0.133, via strong spin–orbit coupling. Fe intercalation introduces extra electronic states near the Fermi-level with a new pocket around the Γ-point and reduced hole-pocket intensity, along with suppressing the charge density wave gap/splitting present in pristine TaS₂, demonstrating effective electronic structure engineering in intercalated transition-metal dichalcogenides observed by angle-resolved photoemission spectroscopy data. Magneto-transport reveals anisotropic magnetoresistance with a butterfly-like behavior below T_C, and a field- and temperature-dependent Hall Effect featuring contributions from both anomalous Hall effect and topological Hall effect (THE). THE arising from DMI-stabilized chiral spin textures and spin fluctuations manifests as a clear kink in transverse resistance below T_C and persists robustly at low temperatures. These findings position Fe_1/2.5TaS₂ as a promising air-stable ferromagnet for exploring DMI-driven chiral phases and spintronic applications at higher temperatures.