Structure refinement and calculated X-ray powder data for the pyrochlore Y2Sn2O7 derived from powder neutron data

Abstract

The structure of pyrochlore type Y₂Sn₂O₇ has been refined by Rietveld analysis from 1.4925 Å neutron powder diffraction data collected at 295 K and containing 46 independent reflections. The refinement figures of merit were R_p = 0.041, R_wp = 0.055, R_exp = 0.039, and R_B = 0.006. The structure is a pyrochlore type, space group (S.G.) with a = 10.3723(1) Å, D_x = 6.21 g cm⁻³, and with the oxygen position parameter of 0.33694(5). The Sn atoms are in a nearly regular octahedral coordination whereas the Y has a distorted 8-fold coordination geometry. The anisotropic thermal parameters were also determined. The refined model has been used to calculate a set of d-I X-ray data for search/match analysis.