Multianvil high-pressure/high-temperature synthesis, crystal structure, and thermal behaviour of the rare-earth borogermanate Ce{sub 6}(BO{sub 4}){sub 2}Ge{sub 9}O{sub 22}

Journal Article · Wed Feb 15 04:00:00 EST 2006 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2005.10.028· OSTI ID:20784872

Heymann, Gunter ^[1]; Huppertz, Hubert ^[1]

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1. Department Chemie und Biochemie, Ludwig-Maximilians-Universitaet Muenchen, Butenandtstrasse 5-13, 81377 Munich (Germany)

The new monoclinic cerium borogermanate Ce{sub 6}(BO{sub 4}){sub 2}Ge{sub 9}O{sub 22} was synthesized under high-pressure and high-temperature conditions in a Walker-type multianvil apparatus at 10.5GPa and 1200 deg. C. Ce{sub 6}(BO{sub 4}){sub 2}Ge{sub 9}O{sub 22} crystallizes with two formula units in the space group P2{sub 1}/n with lattice parameters a=877.0(2), b=1079.4(2), c=1079.1(2) pm, and {beta}=95.94(3){sup o}. As the parameter pressure favours the formation of compounds with cations possessing high coordination numbers, it was possible to produce simultaneously BO{sub 4}-tetrahedra and GeO{sub 6}-octahedra in one and the same borogermanate for the first time. Furthermore, the cerium atoms show high coordination numbers (C.N.: 9 and 11), and one oxygen site bridges one boron and two germanium atoms (O{sup [3]}), which is observed here for the first time. Besides a structural discussion, temperature-dependent X-ray powder diffraction data are presented, demonstrating the metastable character of this high-pressure phase.

• OSTI ID: 20784872
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 179; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
BORATES
CATIONS
CERIUM COMPOUNDS
GERMANATES
LATTICE PARAMETERS
MONOCLINIC LATTICES
OXYGEN IONS
PRESSURE RANGE GIGA PA
SPACE GROUPS
SYNTHESIS
TEMPERATURE DEPENDENCE
X-RAY DIFFRACTION