Neutron scattering from the geometrically frustrated pyrochlore antiferromagnet Tb2Mo2O7 (abstract)

The magnetic metal ions in the cubic pyrochlore Tb2Mo2O7 form an infinite three-dimensional network of corner-sharing tetrahedra with a very high potential for frustration in the presence of antiferromagnetism. Previous bulk susceptibility measurements show strong irreversibilities below a temperature of Tf∼25 K. We have performed neutron scattering measurements that show short range spatial correlations that develop continuously with decreasing temperature, while the characteristic time scale for the fluctuating moments decreases dramatically below Tf. Further, the results indicate extremely slow spin dynamics are relevant near Tf. The low temperature state of this pure material, which exhibits frustration that is solely geometrical in origin, closely resembles that of a spin glass.