title: Structural trends and chemical bonding in Te-doped silicon clathrates.
abstract: The recently discovered tellurium-doped silicon clathrates, Te7+xSi20-x and Te16Si38, both low- and high-temperature forms (cubic and rhombohedral, respectively), exhibit original structures that are all derived from the parent type I clathrate G8Si46 (G = guest atom). The similarities and differences between the structures of these compounds and that of the parent one are analyzed and discussed on the basis of charge distribution and chemical bonding considerations. Because of the particular character of the Te atom, these compounds appear to be at the border between the clathrate and polytelluride families.
authors.affiliation: Institut de Chimie de la Matière Condensée de Bordeaux, UPR-CNRS 9048, Université de Bordeaux 1, 87 Ave. Docteur Albert Schweitzer, 33608 Pessac Cedex, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Jaussaud
authors.forename: Michel
authors.initials: M
authors.lastname: Pouchard
authors.forename: Pierre
authors.initials: P
authors.lastname: Gravereau
authors.forename: Stanislas
authors.initials: S
authors.lastname: Pechev
authors.forename: Graziella
authors.initials: G
authors.lastname: Goglio
authors.forename: Christian
authors.initials: C
authors.lastname: Cros
authors.forename: Alfonso
authors.initials: A
authors.lastname: San Miguel
authors.forename: Pierre
authors.initials: P
authors.lastname: Toulemonde