Neutron spin echo studies of the glass-like pyrochlore y₂Mo ₂O₇

We performed neutron spin echo measurements, on the geometrically frustrated antiferromagnet Y₂Mo₂O₇ to reveal the magnetic nature of this glass-like system close to the freezing temperature, T_f. Diffuse magnetic scattering S(Q), indicative of spatial correlations, were observed to peak at a wave vector, Q = 0.45 Å-1 below 25 K. The normalized intermediate scattering function, S(Q, t)/S(Q, O), was measured as a function of temperature and Q. This provides evidence of the dynamics within the system and reveals at least two relaxation processes above and below T_f ≈ 22.5 K. Crown