Crystal growth, crystal structure of new polymorphic modification, beta-Bi{sub 2}B{sub 8}O{sub 15} and thermal expansion of alpha-Bi{sub 2}B{sub 8}O{sub 15}

Journal Article · Mon Feb 15 00:00:00 EST 2010 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.11.021· OSTI ID:21372505

Bubnova, R S ^[1]; Alexandrova, J V ^[2]; Krivovichev, S V ^[1]; Egorysheva, A V ^[3]

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1. Grebenshchikov Institute of Silicate Chemistry, Russian Academy of Sciences, Makarov Emb 2, 199053 St.Petersburg (Russian Federation)
2. Department of Crystallography, St. Petersburg State University, Universitetskaya nab. 7/9, 199034 St.Petersburg (Russian Federation)
3. Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, Leninsky Prospect 31, GSP-1, Moscow 119991 (Russian Federation)

Single crystals of alpha- and beta-polymorphs of Bi{sub 2}B{sub 8}O{sub 15} were grown by Czochralski method from a charge of the stoichiometric composition. The crystal structure of beta-Bi{sub 2}B{sub 8}O{sub 15} was solved by direct methods from a twinned crystal and refined to R1=0.081 (wR=0.198) on the basis of 1584 unique observed reflections (I>2sigma(I)). The compound is triclinic, space group P1-bar, a=4.3159(8), b=6. 4604(12), c=22.485(4) A, alpha=87.094(15){sup o}, beta=86.538(15){sup o}, gamma=74.420(14){sup o}, V=602.40(19) A{sup 3}, Z=2. The B-O layered anion of beta-Bi{sub 2}B{sub 8}O{sub 15} is topologically identical to the anion of alpha-Bi{sub 2}B{sub 8}O{sub 15} but the orientation of neighboring layers is different. Thermal expansion of alpha-Bi{sub 2}B{sub 8}O{sub 15} has been investigated by X-ray powder diffraction in air in temperature range from 20 to 700 deg. C. It is strongly anisotropic, which can be explained by the hinge mechanism applied to chains of Bi-O polyhedra. While the anisotropy of thermal expansion is rather high, the volume thermal expansion coefficient alpha{sub V}=40x10{sup 6} deg. C{sup -1} for alpha-Bi{sub 2}B{sub 8}O{sub 15} is close to those of other bismuth borates. - Graphical abstract: Typical Bi{sub 2}O{sub 2} unit in crystal structure of alpha- and beta-Bi{sub 2}B{sub 8}O{sub 15}.

• OSTI ID: 21372505
• Journal Information: Journal of Solid State Chemistry, Vol. 183, Issue 2; Other Information: DOI: 10.1016/j.jssc.2009.11.021; PII: S0022-4596(09)00550-7; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ANISOTROPY
BISMUTH COMPOUNDS
BORATES
CRYSTAL GROWTH
CZOCHRALSKI METHOD
MONOCRYSTALS
PHASE TRANSFORMATIONS
SPACE GROUPS
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
THERMAL EXPANSION
TRICLINIC LATTICES
X-RAY DIFFRACTION
BORON COMPOUNDS
COHERENT SCATTERING
CRYSTAL GROWTH METHODS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
DIFFRACTION
EXPANSION
OXYGEN COMPOUNDS
SCATTERING
SYMMETRY GROUPS
TEMPERATURE RANGE