Fluorite-like phases in the BaF2-BiF3-Bi2O3 system-synthesis, conductivity and defect clustering

E. N. Dombrovski (1) , T. V. Serov (1) , E. I. Ardashnikova (1) , V. A. Dolgikh (1) , Malika El Omari (2) , Mohamed El Omari (2) , A. Abaouz (2) , Jean Sénégas (3) , N. G. Chaban (4) , A. M. Abakumov (1) , Gustaaf van Tendeloo (5)

1 Department of Chemistry
2 Department of Chemistry, Faculty of Science
3 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
4 Lomonosov State Academy of Fine Chemical Technology
5 EMAT - Electron Microscopy for Materials Science

A fluorite-like solid solution Ba1 − xBixOzF2 + x − 2z on the basis of cubic BaF2 was synthesised in the BaF2-Bi2O3-BiF3 system and the homogeneity range at 873 K was determined. The samples were studied by X-ray powder diffraction and electron diffraction, and their transport properties were measured by the complex impedance method at 300-623 K. Tendencies of variation of lattice parameters and transport properties were determined. These tendencies are discussed on the basis of a defect clustering hypothesis. Thermal treatment at 573 K of the solid solution, quenched from 873 K results in the formation of a new ordered tetragonal fluorite-like phase with lattice parameters a = 9.5355(4) Å, c = 18.151(1) Å.

Mots clés: Inorganic compounds; X-ray diffraction; Impedance spectroscopy; Electron diffraction

Domaines: Matériaux

E. N. Dombrovski, T. V. Serov, E. I. Ardashnikova, V. A. Dolgikh, Malika El Omari, et al.. Fluorite-like phases in the BaF2-BiF3-Bi2O3 system-synthesis, conductivity and defect clustering. Materials Research Bulletin, 2005, 40 (5), pp.821-830. ⟨10.1016/j.materresbull.2005.02.007⟩. ⟨hal-00022527⟩