Neutron spin echo studies of the glass-like pyrochlore Y2Mo2O7

Abstract We performed neutron spin echo measurements, on the geometrically frustrated antiferromagnet Y 2 Mo 2 O 7 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 A −1 below 25 K. The normalized intermediate scattering function, S(Q,t)/S(Q, 0) , 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.