Crystal structures and reference X-ray powder diffraction patterns ofSr4−xCaxPb2O8(x=1,2,3)

Abstract

The crystal structure of the solid solution alkaline earth plumbate phaseSr4−xCaxPb2O8was investigated using the X-ray Rietveld technique forx=1, 2, and 3. The lattice parametersa,b,c, andVwere found to decrease linearly as the Sr at site 4hwas replaced by Ca. The structure features chains of edge-sharingPbO6octahedra, linked by seven-coordinated (Ca/Sr)–O monocapped trigonal prisms. The structure is similar to that ofPb3O4, which can be reformulated asPb2IIPbIVO4. X-ray diffraction patterns for the solid solution membersSrCa3Pb2O8,Sr2Ca2Pb2O8, andSr3CaPb2O8were prepared for inclusion in the Powder Diffraction File.