title: Flux Crystal Growth and Optical Properties of Two Uranium-Containing Silicates: A2USiO6 (A = Cs, Rb).
abstract: Single crystals of two uranium silicates, Cs2USiO6 and Rb2USiO6, have been grown from molten fluoride fluxes and structurally characterized by single-crystal X-ray diffraction. Cs2USiO6 crystallizes in the body-centered orthorhombic space group, Immm, with a = 8.5812(4) Å, b = 13.0011(6) Å, and c = 13.8811(7) Å. The size of Rb is slightly too small to fit into this structural framework without effecting slight structural changes that result in a 6-fold superstructure. Sharp satellite peaks were observed in the single-crystal X-ray diffraction data, indicating the existing of a superstructure. The crystals were examined by electron diffraction, the results of which suggest that the structure can be thought of as the Immm isotype (a = 8.4916(6) Å, b = 12.6678(9) Å, and c = 13.5077(9) Å) on average, with an approximately 6-fold superstructure along the c axis. The materials were further characterized by UV-vis reflectance spectroscopy.
authors.affiliation: †Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States.
authors.forename: Cory Michael
authors.initials: CM
authors.lastname: Read
authors.affiliation: †Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Smith
authors.affiliation: ‡Research School of Chemistry, The Australian National University, Canberra, Australian Capital Territory 0200, Australia.
authors.forename: Ray
authors.initials: R
authors.lastname: Withers
authors.affiliation: †Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States.
authors.forename: Hans-Conrad
authors.initials: HC
authors.lastname: zur Loye