High pressure synthesis and structure of a novel clathrate-type compound: Te7+xSi20-x (x ∼ 2.5)

• Published in: Solid state sciences Vol. 5; no. 9; pp. 1193 - 1200
• Main Authors: JAUSSAUD, Nicolas, POUCHARD, Michel, GOGLIO, Graziella, CROS, Christian, AMMAR, Abdelaziz, WEILL, Francois, GRAVEREAU, Pierre
• Format: Journal Article
• Language: English
• Published: Paris Elsevier 01.09.2003
• Subjects: Chemical Sciences; Chemistry; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Inorganic chemistry and origins of life; Inorganic compounds; Material chemistry; Miscellaneous; Physics; Preparations and properties; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Ionic cluster; Solid state structure; Electron diffraction; Atomic cluster; Clathrate; High temperature; Experimental study; X ray diffraction; Tellurium; Very high pressure; Inorganic compound; Clathrates; Chemical preparation; Silicon; Inclusion compound; High pressure synthesis# Te-Si system; Crystalline structure; High pressure synthesis; Te–Si system
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/S1293-2558(03)00172-9

A novel clathrate-type compound, Te7+xSi20+x (x ~ 2.5), has been synthesized from the elements under high pressure and high temperature conditions. Its structure has been solved by Rietveld analysis of the XRD powder patterns combined with the results of an electron diffraction study. This structure is closely related to that of a type I clathrate, but with a different unit-cell parameter (a ~ 2 ×a0) and space group (Fd-3c instead of Pm-3n). Its main feature is that it corresponds to a double clathration of a Te atom enclosed in a partially Te substituted (12.5%) Si20 pentagonal dodecahedra, which is itself enclosed in a large Te24 polyhedron, in form of a truncated octahedron...