Paramagnetic moments and localization in1T-TaS2

Abstract

The low-temperature magnetic susceptibility of $1T$-Ta${\mathrm{S}}_2$ is shown to have a contribution from localized paramagnetic moments that are not due to impurities. The density of paramagnetic moments increases as the preparation temperature is increased. This suggests that the moments are due to interstitital defects (intercalated Ta atoms). In some samples a weak remanent magnetization is observed below 4 K as the magnetic field is reduced toward zero, suggesting spin-glass-like ordering of the moments. Since the low-temperature electrical resistivity is dominated by Anderson localization, the magnitude of the resistivity at low temperatures also increases with increasing preparation temperature due to a higher defect density. These results are compared to recently proposed models.