title: Crystal chemistry of anion-excess ReO3-related phases. III. γ-ZrF4, a high-pressure form of zirconiumtetra fluoride, and a comparison of MX4 structure types.
abstract: The crystal structure of the high-pressure (4-8 GPa) form of zirconium tetrafluoride, γ-ZrF4, is based on the association by corner- and edge-sharing of ZrF8 triangulated dodecahedra, forming a three-dimensional framework. It presents some analogies with high-temperature α-ZrF4 but clearly constitutes a new MX4 structure type. The main MX4 ionic structure types, and especially those deriving from the `anion-excess ReO3-type', are compared and it is shown that the TeF4 structure can also be included in this family.
authors.affiliation: Science des Procédés Céramiques et de Traitements de Surface, UMR-CNRS No. 7315, Université de Limoges, Centre Européen de la Céramique, 12 Rue Atlantis, 87068 Limoges Cedex, France.
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Laval
keywords: ReO3-type phase; crystal structure; fluoride glasses; fluorozirconates; high-pressure study; zirconium fluoride