Discovery and Structure Determination of an Unusual Sulfide Telluride through an Effective Combination of TEM and Synchrotron Microdiffraction. Issue 34 (24th July 2015)

• Record Type: Journal Article
• Authors: Fahrnbauer, Felix; Rosenthal, Tobias; Schmutzler, Tilo; Wagner, Gerald; Vaughan, Gavin B. M.; Wright, Jonathan P.; Oeckler, Oliver
• Is Part Of: Angewandte Chemie international edition. Volume 54:Issue 34(2015)
• Page Start: 10020
• Page End: 10023
• Publication Date: 2015-07-24
• Subjects: electron microscopy -- microcrystals -- microfocus synchrotron diffraction -- structure elucidation -- sulfide tellurides; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201503657
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The structure elucidation of the novel sulfide telluride Pb8 Sb8 S15 Te5 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. Pb8 Sb8 S15 Te5 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. Abstract : Treasure quest : The complementary use of electron diffraction and microfocused synchrotron radiation enables innovative and accurate structure analyses of novel compounds in heterogeneous microcrystalline materials. The sulfide telluride Pb8 Sb8 S15 Te5 was discovered this way. It adopts an unusual tetragonal structure type with building blocks that resemble NaCl‐type fragments as well as chain‐like units typical for sulfides.