Static correlation and dynamical properties of Tb3+-moments in Tb2Ti2O7 -: Neutron scattering study

Static and dynamical properties of the magnetic moment system of pyrochlore compound Tb2TiO7 with strong magnetic frustration, have been investigated down to the temperature T = 0.4 K by neutron scattering on a single crystal sample. The scattering vector (Q)-dependence of the magnetic scattering intensity becomes appreciable with decreasing T at around 30K, indicating the development of the magnetic correlation. From the observed energy profiles, the elastic, quasi elastic and inelastic components have been separately obtained. The quasi elastic component corresponds to the diffusive motion of the magnetic moments within the lowest states, which are formed of the lowest energy levels of Tb3+ ions. Magnetic correlation pattern which can roughly reproduce the Q-dependence of the scattering intensities of the elastic and quasi elastic component is discussed based on the trial calculations for clusters of 7 moments belonging to two corner-sharing tetrahedra. A possible origin of the glassy state, which develops at around 1.5 K with decreasing T is discussed.