LiVGe2O6, an anomalous quasi-1D, S=1 system, as revealed by NMR

We report the results of Li-7 nuclear magnetic resonance (NMR) studies of L iVGe2O6,a quasi-one-dimensional spin S = 1 model system, at low temperature s. Our data, including NMR spectra and the temperature dependence of the sp in-lattice relaxation rate T-l(-1) indicate that a first-order phase transi tion occurs at T-c similar or equal to 23 K. The NMR response of LiVGe2O6 b elow T-c suggests that the ordered phase is antiferromagnetic and has unusu al features. Possible reasons for this unexpected behavior are discussed.