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Z. Naturforsch. 2013, 68b, 23 – 28
doi:10.5560/ZNB.2013-2299
Electronic Structure and Bonding in YTi2Ga4 – A Gallide with Linear Titanium Chains and Four-bonded Gallium Atoms
Samir F. Matar1,2 and Rainer Pöttgen3
1 CNRS, ICMCB, UPR 9048, 33600 Pessac, France
2 Université Bordeaux, ICMCB, UPR 9048, 33600 Pessac, France
3 Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 30, 48149 Münster, Germany
Reprint requests to S. F. Matar. E-mail: matar@icmcb-bordeaux.cnrs.fr
Received November 22, 2012 / published online January 10, 2013
The gallium-rich ternary intermetallic compound YTi2Ga4 is isotypic with YbMo2Al4, I4/mmm, Z = 2. Yttrium is located in a large cage built up by 12 gallium atoms. Chains of condensed Y@Ga12 polyhedra and linear titanium chains build up a tetragonal rod packing. The gallium atoms are bonded within Ga4 squares (265 pm Ga–Ga) which are condensed via longer Ga–Ga bonds (292 pm) to a three-dimensional gallium substructure with formally four-connected gallium, in agreement with a Bader charge partitioning scheme [YTi2]4+[Ga4]4−. These features are addressed with electronic structure and chemical bonding considerations. The metallic behavior of YTi2Ga4 is found to be of the itinerant electron type within the valence band and Ti d-like states at EF. Ga–Ga and Ti–Ga bonding characteristics provide mechanical properties derived from the full set of elastic constants leading to a brittle material.
Key words: Gallide, Intermetallic Compound, Electronic Structure, Yttrium, Titanium
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