Dynamical properties of magnetically frustrated pyrochlore system Tb2Ti2O7

sNeutron scattering studies have been carried out on a single crystal of a pyrochlore compound Tb2Ti2O7 with geometrically frustrated magnetic moments. The temperature (T) dependence of the dynamical magnetic properties and dispersion curves of the magnetic excitation have been studied in detail, where we have identified the pattern of the short-range magnetic correlation and determined the T-dependence of the correlation length. Neutron measurements in the magnetic fields (H) up to 4.5 T applied along the [1 (1) over bar1] direction have also been carried out. The magnetic scattering intensity increases at several nuclear Bragg points with increasing H. Although the magnetic structure has not been determined, the results seem to indicate that an antiferromagnetic long-range order is induced by applying the relatively small magnetic field. (C) 2000 Elsevier Science Ltd. All rights reserved.