title: Discovery and Structure Determination of an Unusual Sulfide Telluride through an Effective Combination of TEM and Synchrotron Microdiffraction.
abstract: The structure elucidation of the novel sulfide telluride Pb8Sb8S15Te5 demonstrates a new versatile procedure that exploits the synergism of electron microscopy and synchrotron diffraction methods for accurate structure analyses of side-phases in heterogeneous microcrystalline samples. Suitable crystallites of unknown compounds can be identified by transmission electron microscopy and relocated and centered in a microfocused synchrotron beam by means of X-ray fluorescence scans. The refined structure model is then confirmed by simulating HRTEM images of the same crystallite. Pb8Sb8S15Te5 consists of chains of heterocubane-like units. Cation coordination polyhedra form unusually entwined chains of edge- and face-sharing bicapped trigonal prisms. The structure data are precise enough for bond-valence calculations, which confirm the disordered atom distribution. On this basis, optimization of physical properties becomes feasible.
authors.affiliation: Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststr. 20, 04275 Leipzig (Germany).
authors.forename: Felix
authors.initials: F
authors.lastname: Fahrnbauer
authors.affiliation: Department of Chemistry, University of Munich (LMU), Butenandtstr. 5-13, 81377 Munich (Germany).
authors.forename: Tobias
authors.initials: T
authors.lastname: Rosenthal
authors.affiliation: Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststr. 20, 04275 Leipzig (Germany).
authors.forename: Tilo
authors.initials: T
authors.lastname: Schmutzler
authors.affiliation: Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststr. 20, 04275 Leipzig (Germany).
authors.forename: Gerald
authors.initials: G
authors.lastname: Wagner
authors.affiliation: ESRF-The European Synchrotron, 71, avenue des Martyrs, 38000 Grenoble (France).
authors.forename: Gavin B M
authors.initials: GB
authors.lastname: Vaughan
authors.affiliation: ESRF-The European Synchrotron, 71, avenue des Martyrs, 38000 Grenoble (France).
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Wright
authors.affiliation: Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststr. 20, 04275 Leipzig (Germany). oliver.oeckler@gmx.de.
authors.forename: Oliver
authors.initials: O
authors.lastname: Oeckler
keywords: electron microscopy; microcrystals; microfocus synchrotron diffraction; structure elucidation; sulfide tellurides