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 Fe0.28TaS2 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 FexTaS2 crystals with 0.23 <= x <= 0.35, demonstrating that crystallographic defects lead to spin disorder, which correlates with magnetotransport properties, such as switching magnetic field H-S, magnetoresistance (MR), and even zero-field resistivity rho(0) and temperature coefficient A in rho(T) = rho(0) + AT(2): The ordering temperature T-C and Weiss temperature theta(W) are maximized at the superstructure composition x = 1/4, whereas H-s, MR, rho(0), and A are minimum. Conversely, at a composition intermediate between the superstructure compositions x = 1/4 and 1/3, the corresponding magnetotransport properties reach local maxima.