LOW-TEMPERATURE ELECTRONIC AND MAGNETIC-PROPERTIES OF SINGLE-CRYSTAL NI3S2

Electrical transport is measured for a crystal and polycrystalline samples of Ni3S2. 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/K2 Mol(Ni). The magnetic measurements on single-crystal and polycrystalline samples yield a mass magnetic susceptibility of 0.3 X 10(-6) emu/g [0.4 X 10(-8) M3/g], which is essentially temperature independent. The Pauli paramagnetic susceptibility is determined to be 5.0 X 10(-5) emu/mol(Ni) [6.3 X 10(-10) M3/Mol(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 Ni3S2 may be categorized as a good metallic conductor for which magnetic instabilities and electronic interactions are of marginal importance.