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Unconventional resistivity at the border of metallic antiferromagnetism in NiS2

P. G. Niklowitz·M. J. Steiner·G. G. Lonzarich·D. Braithwaite·G. Knebel·J. Flouquet·J. A. Wilson
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Abstract

We report low-temperature and high-pressure measurements of the electrical resistivity ρ(T) of the antiferromagnetic compound NiS_2 in its high-pressure metallic state. The form of ρ(T) suggests that metallic antiferromagnetism in NiS_2 is quenched at a critical pressure p_c=76+-5 kbar. Near p_c the temperature variation of ρ(T) is similar to that observed in NiS_{2-x}Se_x near the critical composition x=1 where the Neel temperature vanishes at ambient pressure. In both cases ρ(T) varies approximately as T^{1.5} over a wide range below 100 K. However, on closer analysis the resistivity exponent in NiS_2 exhibits an undulating variation with temperature not seen in NiSSe (x=1). This difference in behaviour may be due to the effects of spin-fluctuation scattering of charge carriers on cold and hot spots of the Fermi surface in the presence of quenched disorder, which is higher in NiSSe than in stoichiometric NiS_2.

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P. G. Niklowitz, M. J. Steiner, G. G. Lonzarich, D. Braithwaite, G. Knebel, J. Flouquet, J. A. Wilson. 2006-10-05. Unconventional resistivity at the border of metallic antiferromagnetism in NiS2. https://doi.org/10.1103/physrevb.77.115135

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