title: Structures of the ordered double perovskites Sr2YTaO6 and Sr2YNbO6.
abstract: The ordered perovskite Sr(2)YTaO(6), distrontium yttrium tantalum hexaoxide, has been reported as showing an unusual triclinic structure, at odds with the results from a recent group-theoretical analysis. A new investigation establishes that Sr(2)YTaO(6) and the isostructural Sr(2)YNbO(6), distrontium yttrium niobium hexaoxide, in fact both adopt the commonly occurring monoclinic structure, with the space-group symmetry P2(1)/n.
authors.affiliation: Australian Nuclear Science and Technology Organisation, Private Mail Bag 1, Menai, NSW 2234, Australia. cjh@ansto.gov.au
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Howard
authors.forename: Paris W
authors.initials: PW
authors.lastname: Barnes
authors.forename: Brendan J
authors.initials: BJ
authors.lastname: Kennedy
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Woodward
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D015394:Molecular Structure; D009556:Niobium / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D017601:Oxygen Compounds / Q000737:chemistry*; D013324:Strontium / Q000737:chemistry*; D013635:Tantalum / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry; D015019:Yttrium / Q000737:chemistry*
chemical_list: D017610:Calcium Compounds; D010087:Oxides; D017601:Oxygen Compounds; D009556:Niobium; C059910:perovskite; D015019:Yttrium; D013635:Tantalum; D014025:Titanium; D013324:Strontium