NMR Investigations on the Spin Fluctuations in Itinerant Antiferromagnets. II. V₃S₄ and V₅S₈

Abstract

The properties of the spin density fluctuations in the itinerant antiferromagnetic compounds V₃S₄ and V₅S₈ have been investigated in both the paramagnetic and the antiferromagnetic states by using the pulsed NMR technique. Although it has been proposed that V₃S₄ is one of weak itinerant antiferromagnets because of the low ordering temperature, small staggered moment M_Q and the temperature dependence of M_Q, the temperature dependence of the nuclear spin-lattice relaxation rate 1/T₁ are not in accord with the prediction based on the self-consistent renormalization theory of spin fluctuations for weak itinerant antiferromagnets. In V₅S₈, the observed temperature independent process of 1/T₁ in the paramagnetic state and the temperature dependences of the bulk susceptibility and M_Q are not explained from either weakly magnetic limit or localized moment limit, suggesting this material is in the intermediate magnetic regime.