Correlations of crystallographic defects and anisotropy with magnetotransport properties in FexTaS2 single crystals (0.23≤x≤0.35)

Very large magnetoresistance discovered in single crystals of the ferromagnetic Fe-intercalated transition metal dichalcogenide, Fe_0.28TaS₂ was attributed to the deviation of the Fe concentration from commensurate values (x = 1/4 or 1/3), which caused magnetic moment misalignments. Here we report a study of Fe_xTaS₂ crystals with 0:23 ≤ x ≤ 0:35, demonstrating that crystallographic defects lead to spin disorder, which correlates with magneto-transport properties such as switching magnetic fi eld HS, magnetoresistance MR, and even zero-field resistivity ρ0 and temperature coefficient A in ρ(T) = ρ₀ + AT₂: The ordering temperature T_C and Weiss temperature θ_W are maximized at the superstructure composition x = 1/4, while H_s, MR, ρ₀, and A are minimum. Conversely, at a composition intermediate between the superstructure compositions x = 1/4 and 1/3, the corresponding magneto-transport properties reach local maxima.