Electronic structure and bonding in YTi2Ga4 - A gallide with linear titanium chains and four-bonded gallium atoms

Samir F. Matar (1) , Rainer Pöttgen (2)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 WWU - Westfälische Wilhelms-Universität Münster = University of Münster

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.

Mots clés: Gallide; Intermetallic compound; Electronic structure; Yttrium; Titanium

Domaines: Matériaux

Samir F. Matar, Rainer Pöttgen. Electronic structure and bonding in YTi2Ga4 - A gallide with linear titanium chains and four-bonded gallium atoms. Zeitschrift fur Naturforschung B, 2013, 68 (1), pp.23-28. ⟨10.5560/ZNB.2013-2299⟩. ⟨hal-00777673⟩