Abstract Here, we present a systematic study of de Haas-van Alphen oscillations (dHvA),topological phase, and anomalous Hall effect (AHE) of Ni0.5Co0.5Se single crystal.Low-temperature longitudinal resistivity ρxx(T) under different magnetic fields exhibits anupturn, indicative of a semimetallic phase. Fitting of the zero-field ρxx(T) data with theBloch-Gruneisen-Mott model including Kondo resistivity term reveals multiple scatteringmechanisms, which is substantiated by the deviation from Kohler’s rule of themagnetoresistance curves. At T = 2 K and low magnetic fields, the observed cusp-likefeatures indicate weak antilocalization effect, quantitatively described using a modifiedHikami-Larkin-Nagaoka equation. Temperature dependent magnetization (M-T) curvesand magnetic field dependent isothermal magnetization (M-B) curves reveal the existenceof weak ferromagnetic phase at very low temperatures. The weak fieldmagnetoconductivity data follows the-ln(B) dependency and the observed strong highfield dHvA oscillations in (M-B) curves, provide the evidence of non-zero Berry phase,confirms the non-trivial band topology. These signatures indicate that Ni0.5Co0.5Se is atopological nodal line semimetal. In Hall resistivity data, significant AHE is observed at 2K to 5 K and the linear behavior of the anomalous Hall resistivity (ρAxy) with ρxx signifiesthat the extrinsic skew scattering mechanism contributes to AHE in Ni0.5Co0.5Se.
Pradhan et al. (Wed,) studied this question.