Synthesis and crystal structures of the new metal-rich ternary borides Ni{sub 12}AlB{sub 8}, Ni{sub 12}GaB{sub 8} and Ni{sub 10.6}Ga{sub 0.4}B{sub 6}-examples for the first B{sub 5} zig-zag chain fragment

Journal Article · Sun Aug 15 00:00:00 EDT 2010 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2010.05.009· OSTI ID:21421577

Ade, Martin; Kotzott, Dominik ^[1]; Hillebrecht, Harald ^[1]

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1. Albert-Ludwigs-Universitaet Freiburg, Institut fuer Anorganische und Analytische Chemie, Albertstrasse 21, D-79104 Freiburg (Germany)

Single crystals of the new borides Ni{sub 12}AlB{sub 8}, and Ni{sub 10.6}Ga{sub 0.4}B{sub 6} were synthesized from the elements and characterized by XRD and EDXS measurements. The crystal structures were refined on the basis of single crystal data. Ni{sub 12}AlB{sub 8} (oC252, Cmce, a=10.527(2), b=14.527(2), c=14.554(2) A, Z=12, 1350 reflections, 127 parameters, R{sub 1}(F)=0.0284, wR{sub 2}(F{sup 2})=0.0590) represents a new structure type with isolated B atoms and B{sub 5} fragments of a B-B zig-zag chain. Because the pseudotetragonal metric crystals are usually twinned. Ni{sub 10.6}Ga{sub 0.4}B{sub 6} (oP68, Pnma, a=12.305(2), b=2.9488(6), c=16.914(3) A, Z=4, 1386 reflections, 86 parameters, R{sub 1}(F)=0.0394, wR{sub 2}(F{sup 2})=0.104) is closely related to binary Ni borides. The structure contains B-B zig-zag chains and isolated B atoms. Ni{sub 12}GaB{sub 8} is isotypical to the Al-compound (a=10.569(4), b=14.527(4) and c=14.557(5) A). - Graphical abstract: Pentameric B{sub 5}-units are longest fragments of a B-B zig-zag chain ever characterized in a boride. They are found in the structures of Ni{sub 12}AlB{sub 8} and Ni{sub 12}GaB{sub 8}. The compounds are formed on annealing boron-rich {tau}-borides like Ni{sub 20}AlB{sub 14}.

• OSTI ID: 21421577
• Journal Information: Journal of Solid State Chemistry, Vol. 183, Issue 8; Other Information: DOI: 10.1016/j.jssc.2010.05.009; PII: S0022-4596(10)00198-2; Copyright (c) 2010 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
ALUMINIUM COMPOUNDS
ANNEALING
CRYSTAL GROWTH
GALLIUM COMPOUNDS
MONOCRYSTALS
NICKEL BORIDES
ORTHORHOMBIC LATTICES
SYNTHESIS
X-RAY DIFFRACTION
BORIDES
BORON COMPOUNDS
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
DIFFRACTION
HEAT TREATMENTS
NICKEL COMPOUNDS
SCATTERING
TRANSITION ELEMENT COMPOUNDS