Published January 15, 1989 | Version v1
Journal article

Oxygen vacancy ordering in the defect pyrochlore Pb2[TiSb]O6.5: A Rietveld refinement of neutron powder diffraction data

  • 1. Consejo Superior de Investigaciones Cientificas, Madrid (Spain). Inst. de Ciencia de Materiales
  • 2. Institut Max von Laue - Paul Langevin, 38 - Grenoble (France)

Description

Mr=688.13, cubic, Fanti 43m, a=10.4109 (2) A, V=1128.40 (6) A3, Z=8, Dx=8.10 Mg m-3, neutron powder diffraction (Rietveld method), λ=1.9109 A, T295 K, Rp=5.40, Rwp=7.14, Re=5.48, RI=1.69% for 52 integrated Bragg intensities, goodness of fit Rg=1.70. Oxygen coordination polyhedra for Ti,Sb are nearly regular octahedra, whereas that for Pb is a scalenohedron with the eight vertex unoccupied. The Pb atoms are displaced by 0.040 (4) A along th [111] direction from the ideal Fdanti 3m pyrochlore structure, producing small tetrahedral cages [Pb-Pb distances 3.617 (3) A] inside which the oxygen vacancies show an ordered arrangement. (orig.)

Additional details

Publishing Information

Journal Title
Acta Crystallographica, Section C
Journal Volume
45
Journal Issue
1
Series
Acta Crystallogr., Sect. C.
Journal Page Range
3-7
ISSN
0108-2701
CODEN
ACSCE