51V-NMR study of the misfit layer compounds La1.17-xSrxVS3.17

Electronic properties of La 1.17- x Sr x VS 3.17 , which undergoes a clear phase transition at around x ∼0.17 (or at the V-valency of +3) with decreasing temperature T to a nonmagnetic ground state, have been investigated by 51 V-NMR as a function of the Sr-concentration x . The relaxation rate divided by T , 1/ T 1 T seems to be almost T -independent for all samples studied here (0.0≤ x ≤0.35) above the phase transition temperature and becomes maximum at around x =0.17. Below the transition, 1/ T 1 T exhibits activation-type behavior except the very low temperature region where the T -dependence is much weaker. The activation energy decreases rapidly with increasing x in the region of the V-valency larger than +3. The 1/ T 1 T values of the samples with x around 0.17 become nearly equal to zero at low temperatures, indicating that their spin susceptibilities vanish almost completely. It suggests that the transition to the nonmagnetic ground state is driven by a singlet formation with rather local nature....