title: Single-crystal study of the m = 2 tubular cobalt oxide, Bi(4)Sr(12)Co(8)O(30-delta).
abstract: The structure of the m = 2 tubular compound Bi(4)Sr(12)Co(8)O(30-delta), bismuth strontium cobalt oxide, was determined by single-crystal X-ray diffraction. This phase of orthorhombic symmetry exhibits a very strong tetragonal pseudosymmetry. The structure consists of 90 degrees -oriented Bi(2)Sr(2)CoO(6+delta) slices, four Co atoms wide, forming [Sr(4)Co(4)O(13)](infinity) pillars at their intersection. The Co atoms in these pillars form four corner-sharing CoO(5) bipyramids. In the resulting [Co(4)O(13)] cluster, an anionic disorder is evidenced and discussed. Then, an accurate description of the particular structure of the pillars is given. Finally, a comparison with the Mn tubular compound Bi(3.6)Sr(12.4)Mn(8)O(30-delta) is carried out.
authors.affiliation: Laboratoire CRISMAT (UMR CNRS 6508), ISMRA, 6 Bd du Maréchal Juin, 14050 Caen, France. olivier.perez@ismra.fr
authors.forename: Olivier
authors.initials: O
authors.lastname: Perez
authors.forename: A C
authors.initials: AC
authors.lastname: Masset
authors.forename: H
authors.initials: H
authors.lastname: Leligny
authors.forename: G
authors.initials: G
authors.lastname: Baldinozzi
authors.forename: D
authors.initials: D
authors.lastname: Pelloquin
authors.forename: M
authors.initials: M
authors.lastname: Dutheil