Defect introduced paramagnetism and weak localization in two-dimensional metal VSe₂

Abstract

We have carried out a detailed investigation of the magnetism, valence state, and magnetotransport in VSe₂ bulk single crystals, as well as in laminates obtained by mechanical exfoliation. In sharp contrast to the ferromagnetic behavior reported previously, here, no ferromagnetism could be detected for VSe₂ single crystal and laminate from room temperature down to 2 K. Neither did we find the Curie paramagnetism expected due to the 3d ¹ odd-electronic configuration of covalent V⁴⁺ ions. Rather, intrinsic VSe₂ is a non-magnetic alloy without local moment. Only a weak paramagnetic contribution introduced by defects is noticeable below 50 K. A weak localization effect due to defects was also observed in VSe₂ single crystals for the first time.