| Autor: |
Grahlow F; Section for Solid State and Theoretical Inorganic Chemistry, Institute of Inorganic Chemistry, Eberhard Karls Universität Tübingen, uf der Morgenstelle 18, Tübingen D-72076, Germany., Strauß F; Institute of Physical and Theoretical Chemistry, Eberhard Karls Universität Tübingen, Tübingen D-72076, Germany., Schmidt P; Section for Solid State and Theoretical Inorganic Chemistry, Institute of Inorganic Chemistry, Eberhard Karls Universität Tübingen, uf der Morgenstelle 18, Tübingen D-72076, Germany., Valenta J; International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki 305-0047, Japan., Ströbele M; Section for Solid State and Theoretical Inorganic Chemistry, Institute of Inorganic Chemistry, Eberhard Karls Universität Tübingen, uf der Morgenstelle 18, Tübingen D-72076, Germany., Scheele M; Institute of Physical and Theoretical Chemistry, Eberhard Karls Universität Tübingen, Tübingen D-72076, Germany., Romao CP; Department of Materials, ETH Zürich, Wolfgang-Pauli-Str. 27, Zürich 8093, Switzerland., Meyer HJ; Section for Solid State and Theoretical Inorganic Chemistry, Institute of Inorganic Chemistry, Eberhard Karls Universität Tübingen, uf der Morgenstelle 18, Tübingen D-72076, Germany. |
| Abstrakt: |
The compound Ta 4 SBr 11 was prepared by a comproportionation reaction of tantalum bromide with tantalum and elemental sulfur. The crystal structure, as refined by single-crystal X-ray diffraction, is composed of clusters with Ta 4 S cores, arranged in corrugated van der Waals layers. Individual layers appear to be displaced relative to each other along one direction. Successful crystal growth in a melt of CsBr yielded black platelets of Ta 4 SBr 11 , which were used to investigate the electrical properties of the compound. The electronic structure was studied by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy and by density functional theory (DFT) band structure calculations, revealing this material to be a small-gap semiconductor. DFT results, in combination with magnetic susceptibility measurements, suggest that metallicity originating from the one unpaired Ta d electron per cluster is most likely suppressed by electronic correlations, forming a cluster Mott insulator. |
