Peculiar magnetism and magneto-transport properties in a non-centrosymmetric self-intercalated van der Waals ferromagnet Cr5Te8

Trigonal Cr5Te8, a self-intercalated van der Waals ferromagnet with an out of plane magnetic anisotropy, has long been known to crystallise in a centrosymmetric structure. Through detailed structural analysis together with second harmonic generation experiments, we show that the compound actually adopts a non-centrosymmetric structure. A large anomalous Hall conductivity of 102 Ω^(-1) cm^(-1) at low temperature stems from intrinsic origin, which is larger than any previously reported values in bulk Cr-Te system. In addition, we observe a hump-like feature in the field-dependent Hall resistivity data, resembling a typical topological Hall signal. We demonstrate that the feature is highly tunable and is not related to topological Hall effect even though we observe Néel-type skyrmions by Lorentz transmission electron microscopy which is consistent with the non-centrosymmetric structure of the compound.