LAUSR

The temperature-driven change of the Fermi surface has been attracting attention recently as it is fundamental and essential to understand a metallic system. Here we report the magnetotransport anomalies in the semimetal HfTe2 single crystals. The magnetoresistance (MR) behavior at high temperatures obeys the Kohler's rule which can lead to the field-induced resistivity upturn behavior as observed. When the temperature is decreased to around 30 K, the Kohler's rule becomes inapplicable indicating the change of the Fermi surface in HfTe2. The Hall analyses and extended Kohler's plot reveal abrupt change of carrier densities and mobilities near 30 K. These results suggest that the chemical potential may move downwards with increased temperature involving the disappearance of an electron pocket. Our work of the temperature-driven Lifshitz transition in HfTe2 is relevant for the understanding of the transport anomalies and exotic physical properties in transition-metal dichalcogenides.