Layered GaGe2Te: structure and chemical bonding

Zeitschrift für anorganische und allgemeine Chemie, vol. 649

Abstract

Abstract The 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.

Authors 5

1. Tobias R. Juhlke

   Leipzig University

   Affiliation as printed

   Faculty of Chemistry and Mineralogy Institute of Mineralogy, Crystallography and Materials Science Scharnhorststr. 20 04275 Leipzig Germany

   Faculty of Chemistry and Mineralogy Institute of Mineralogy, Crystallography and Materials Science Scharnhorststr. 20 04275 Leipzig Germany

2. Simon Steinberg Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Inorganic Chemistry RWTH Aachen University Landoltweg 1 52074 Aachen Germany

   RWTH: Rheinisch-Westfalische Technische Hochschule Aachen, Institute of Inorganic Chemistry, Aachen, GERMANY

3. Lennart Staab

   Leipzig University

   Affiliation as printed

   Faculty of Chemistry and Mineralogy Institute of Mineralogy, Crystallography and Materials Science Scharnhorststr. 20 04275 Leipzig Germany

   Faculty of Chemistry and Mineralogy Institute of Mineralogy, Crystallography and Materials Science Scharnhorststr. 20 04275 Leipzig Germany

4. Eleanor Lawrence Bright

   European Synchrotron Radiation Facility

   Affiliation as printed

   ESRF – The European Synchrotron ID11, Structure of Materials Group 38043 Grenoble Cedex 9 France

   ESRF – The European Synchrotron ID11, Structure of Materials Group 38043 Grenoble Cedex 9 France

5. Oliver Oeckler corresponding

   Leipzig University

   Affiliation as printed

   Faculty of Chemistry and Mineralogy Institute of Mineralogy, Crystallography and Materials Science Scharnhorststr. 20 04275 Leipzig Germany

   Faculty of Chemistry and Mineralogy Institute of Mineralogy, Crystallography and Materials Science Scharnhorststr. 20 04275 Leipzig Germany