Extended Kohler's scaling and Isosbestic point in the charge density wave state of 1T-VSe2.

Abstract

1T-VSe₂is a narrow band transition metal chalcogenide that shows charge density wave (CDW) state below T_CDW= 110 K. Here, we have explored the relevance of Kohler's rule and the thermal transport properties of VSe₂across the CDW state in the presence of magnetic field. The magnetoresistance (MR) follows Kohler's rule above T_CDW, while an extended Kohler's rule is employed below T_CDW. Interestingly, we observed an anomaly in MR around T ∼ 20 K, below which MR value decreases on lowering temperature. This anomaly is also reflected in the slope (κ) of Kohler's plots and the relative change in the thermal excitation induced carrier density (n_T). Despite a strong magnetic field of 14 Tesla, the T_CDWremains largely unaffected in both electrical resistivity (ρ(T)) and Seebeck coefficient (S), although the application of magnetic field does enhance the peak intensity of S around T ∼ 60 K. The crossover of S curves measured at different magnetic fields at T ∼ 20 K suggests the existence of a novel feature within the CDW state of VSe₂i.e., the presence of a locally exact isosbestic point.