The crystal structure of the spin-glass pyrochlore, Y2Mo2O7

The crystal structure of the spin-glass material, Y2Mo2O7, has been determined from powder neutron diffraction data using profile (Rietveld) methods. The data are consistent with the fully ordered cubic pyrochlore structure, a0 = 10.230(1) Å with Y in 16d, Mo in 16c, O in 48f(x = 0.3382(1)), and O′ in 8b of Fd3m. Attempts to refine models with O′ disordered over the 32e sites or between the 8a and 8b sites resulted in convergence to the 8b …