Preparation, crystal structure and thermal expansion of a new bismuth barium borate, BaBi{sub 2}B{sub 4}O{sub 10}

Journal Article · Thu Feb 15 00:00:00 EST 2007 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2006.11.001· OSTI ID:21015689

Bubnova, R S ^[1]; Krivovichev, S V ^[2]; Egorysheva, A V ^[3]; Kargin, Y F ^[3]

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1. Grebenshchikov Institute of the Silicate Chemistry of the Russian Academy of Sciences, Makarov Emb. 2, St. Petersburg 199034 (Russian Federation)
2. Department of Crystallography, St. Petersburg State University, University Emb. 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 a new compound, BaBi{sub 2}B{sub 4}O{sub 10} were grown by cooling a melt with the stoichiometric composition. The crystal structure of the compound has been solved by direct methods and refined to R {sub 1}=0.049 (wR=0.113) on the basis of 1813 unique observed reflections (|F {sub o}|>4{sigma}|F {sub o}|). It is monoclinic, space group P2{sub 1}/c, a=10.150(2), b=6. 362(1), c=12.485(2) A, {beta}=102.87(1){sup o}, V=786.0(2) A{sup 3}, Z=4. The structure is based upon anionic thick layers that are parallel to (001). The layers can be described as built from alternating novel borate [B{sub 4}O{sub 10}]{sup 8-} {sub {infinity}} chains and bismuthate [Bi{sub 2}O{sub 5}]{sup 4-} {sub {infinity}} chains extended along b-axis. The borate chains are composed of [B{sub 3}O{sub 8}]{sup 7-} triborate groups of three tetrahedra and single triangles with a [BO{sub 2}]{sup -} radical. The borate chains are interleaved along the c-axis with rows of the Ba{sup 2+} cations so that the Ba atoms are located within the layers. The layers are connected by two nonequivalent Ba-O bonds as well as by two equivalent Bi-O bonds with bond valences in the range of 0.2-0.3 v.u. Thermal expansion of BaBi{sub 2}B{sub 4}O{sub 10} studied by high-temperature X-ray powder diffraction in the temperature range of 20-700 deg. C (temperature step 30-35 deg. C) is highly anisotropic. While the b and c unit-cell parameters increase almost linearly on heating, temperature dependencies of a parameter and {beta} monoclinic angle show nonlinear behavior. As a result, on heating orientation of thermal expansion tensor changes, and bulk thermal expansion increases from 20x10{sup -6} deg. C{sup -1} at the first heating stage up to 57x10{sup -6} deg. C{sup -1} at 700 deg. C that can be attributed to the increase of thermal mobility of heavy Bi{sup 3+} and Ba{sup 2+} cations. - Graphical abstract: New borate and bismuthate one-dimensional polyions.

• OSTI ID: 21015689
• Journal Information: Journal of Solid State Chemistry, Vol. 180, Issue 2; Other Information: DOI: 10.1016/j.jssc.2006.11.001; PII: S0022-4596(06)00586-X; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ANISOTROPY
BARIUM COMPOUNDS
BARIUM IONS
BISMUTH COMPOUNDS
BISMUTH IONS
BORATES
HEATING
LAYERS
MONOCLINIC LATTICES
MONOCRYSTALS
SPACE GROUPS
STOICHIOMETRY
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
THERMAL EXPANSION
X-RAY DIFFRACTION