Affiliation:
1. Faculty of Chemistry and Mineralogy Institute of Mineralogy, Crystallography and Materials Science Scharnhorststr. 20 04275 Leipzig Germany
2. Institute of Inorganic Chemistry RWTH Aachen University Landoltweg 1 52074 Aachen Germany
3. ESRF – The European Synchrotron ID11, Structure of Materials Group 38043 Grenoble Cedex 9 France
Abstract
AbstractThe structure of the new compound GaGe2Te has been determined using nanofocused synchrotron radiation. The trigonal structure (space group P
m1, a=4.0443(3) Å, c=14.923(2) Å, V=211.38(4) Å3; Z=2) consists of Ge bilayers sandwiched by Ga−Te layers. Ge and Ga are tetrahedrally coordinated. The layer packages are separated by a van der Waals gap with a Te−Te distance of 4.1502(7) Å. The structure resembles that of GaGeTe but features an additional Ge atom layer. Despite small scattering contrast of Ga and Ge, precise high‐resolution data enable unequivocal atom assignment as confirmed by R values of different models. DFT calculations suggest only a small extent of charge transfer, which is confirmed by both Bader and Mulliken charges. Thus, bonding within the layer packages is predominantly covalent, especially between Ga and Ge. Formal oxidation states according to GaIIIGe(0)Ge−ITe−II, i. e. assuming rather ionic Ge−Ga bonds, convey a much less realistic situation than GaIIGe2(0)Te−II, which is in line with GaGeTe.
Funder
European Synchrotron Radiation Facility