title: Reinvestigation of the structure of BaCuSi(2)O(6) -- evidence for a phase transition at high temperature.
abstract: Superstructure reflections have been observed in the room-temperature X-ray diffraction pattern of BaCuSi(2)O(6), barium copper disilicate. The tetragonal structure has a fourfold unit-cell volume compared with the original structure determined by Finger et al. At T(s) = 610 K BaCuSi(2)O(6) undergoes a structural phase transition upon which the superstructure reflections disappear. The description of the structure in the larger cell removes the crystal-chemical inconsistencies observed for the original structure.
authors.affiliation: Institut für Kristallographie, RWTH Aachen, 52056 Aachen, Germany.
authors.forename: Karine M
authors.initials: KM
authors.lastname: Sparta
authors.forename: Georg
authors.initials: G
authors.lastname: Roth