Incommensurate magnetic ordering and spin-liquid-like state in a triangular lattice BaVS3: Neutron diffraction and scattering study

We performed powder neutron diffraction and scattering experiments of the S = 1/2 triangular lattice system, BaVS3, and found magnetic reflections bel ow T-X similar or equal to 30 K. The propagation vector is determined to be incommensurate (0.226 0.226 0) in the hexagonal index. The ordered moment is roughly estimated to be similar to 0-5 mu(B)/V. Although the elastic mag netic diffractions disappear above T-X, low-energy inelastic scattering, wh ich has an Q - omega dispersion similar to that below T-X, was observed bet ween T-X and the metal-insulator transition point T-MI similar or equal to 70 K, indicating the presence of a long-range and dynamic antiferromagnetic correlation, i.e., a spin-liquid-like state, between T-X and T-MI.