Low-temperature electronic and magnetic properties of single-crystalNi3S2

Abstract

Electrical transport is measured for a crystal and polycrystalline samples of ${\mathrm{Ni}}_3$ ${\mathrm{S}}_2$. The samples display metallic behavior with the relative resistance decreasing by more than two orders of magnitude upon cooling from 300 to 4.5 K. Low-temperature heat-capacity data are obtained by the quasiadiabatic heat-pulse method. The electronic-heat-capacity constant is determined to be 2.7 mJ/${\mathrm{K}}^2$ ${\mathrm{mol}}_{\mathrm{Ni}}$. The magnetic measurements on single-crystal and polycrystalline samples yield a mass magnetic susceptibility of 0.3×${10}^{\mathrm{-}6}$ emu/g [0.4×${10}^{\mathrm{-}8}$ ${\mathrm{m}}^3$/g], which is essentially temperature independent. The Pauli paramagnetic susceptibility is determined to be 5.0×${10}^{\mathrm{-}5}$ emu/${\mathrm{mol}}_{\mathrm{Ni}}$ [6.3×${10}^{\mathrm{-}10}$ ${\mathrm{m}}^3$/${\mathrm{mol}}_{\mathrm{Ni}}$], corrected for the underlying diamagnetism. Results of the electrical transport, magnetic, and heat-capacity measurements are used to characterize the electronic structure. Application of the standard theory of electron-correlation phenomena shows that ${\mathrm{Ni}}_3$ ${\mathrm{S}}_2$ may be categorized as a good metallic conductor for which magnetic instabilities and electronic interactions are of marginal importance.