Yttrium barium heptaoxocobaltate YBaCo4O7+δ: Refinement of the structure and determination of the composition

Parameters of the crystal structure of compound YBaCo4O7 are refined. The experimental data [3917 reflections measured, 469 unique I hkl , and 420 observed reflections with I > 2σ(I)] are obtained on a Bruker X8APEX automated diffractometer equipped with a CCD detector [MoK α, graphite monochromator, θmax = 33.09°, space group P63 mc, a = 6.3058(4) A, c = 10.2442(7) A, V = 352.77 A3, Z = 2, d calcd = 5.404 g/cm3, R 1 = 0.0183 for 420 observed reflections and 0.0216 for all unique reflections]. The refinement shows that the occupancy factors of all sites of the space group correspond within three standard deviations to the standard values, that is, to the Y: Ba: Co: O = 1: 1: 4: 7 whole-number ratio of elements in the formula of the compound and to the absence of an aluminum impurity in the crystal.