Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-26T08:03:07.363Z Has data issue: false hasContentIssue false

Ab initio determination and Rietveld refinement of the crystal structure of Ba7Cl2F12

Published online by Cambridge University Press:  10 January 2013

B. Es-Sakhi
Affiliation:
Laboratoire d’Instrumentation et de Mesures (LIM), Département de Physique, Faculté des Sciences, Université Ibnou Zohr, 80000 Agadir, Maroc
P. Gravereau
Affiliation:
Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB-CNRS), 87, Av. Schweitzer, 33608 Pessac Cedex, France
C. Fouassier
Affiliation:
Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB-CNRS), 87, Av. Schweitzer, 33608 Pessac Cedex, France

Abstract

The structure of Ba7Cl2F12 has been determined ab initio from conventional X-ray powder diffraction data by the “heavy atom” method. The cell is hexagonal (space group P6¯, Z=1), with a=10.6373(2) Å and c=4.1724(2) Å. Refinement of 38 parameters by the Rietveld method, using 278 reflections, leads to cRwp=0.173, cRp=0.135, and RB=0.054. The structure has common characteristics with that of the other BaF2-rich fluorochloride, Ba12Cl5F19. In both phases Ba2+ ions lie in tricapped trigonal prisms formed by nine halide ions, and Cl ions occupy the center of trigonal prisms of Ba2+ ions. F ions are located in cationic tetrahedra or square pyramids.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bergman, A. G., and Bukhalova, G. A. (1949). “Exchange decomposition in non miscible solutions: Formation of complex, solid solution and exchange decomposition in melts of strontium and barium fluorides and chlorides,” Russ. J. Gen. Chem. 19, 603611.Google Scholar
Bérar, J.-F., and Lelann, P. (1991). “E. S. D.'s and estimate probable errors obtained in Rietveld refinements with local corrections,” J. Appl. Crystallogr. 24, 15.CrossRefGoogle Scholar
Brixner, L. H. (1987). “New x-ray phosphors,” Mater. Chem. Phys. 16, 253281.CrossRefGoogle Scholar
Boultif, A., and Louër, D. (1991). “Indexing of powder diffraction patterns for low symmetry lattices by the successive dichotomy method,” J. Appl. Crystallogr. 24, 987993.CrossRefGoogle Scholar
Caglioti, G., Paoletti, A., and Ricci, F. P. (1958). “Choice of collimators for a crystal spectrometer for neutron diffraction,” Nucl. Instrum. 3, 223228.CrossRefGoogle Scholar
Fessenden, E., and Lewin, S. Z. (1955). “X-ray diffraction study of the precipitation of barium from solutions containing chloride, fluoride and sulfate. Formation and properties of barium chlorotrifluoride,” J. Am. Chem. Soc. 77, 42214222.CrossRefGoogle Scholar
Haase, A., and Brauer, G. (1978). “Hydratstufen und Kristallstrukturen von Bariumchlorid,” Z. Anorg. Allg. Chem. 441, 181195.CrossRefGoogle Scholar
Khardikova, E. Ya. (1980). “The Ba, Ca, Li // Cl, F reciprocal system,” Russ. J. Inorg. Chem. 25, 914916.Google Scholar
Kubel, F., Hagemann, H., and Bill, H. (1996). “Synthesis and structure of Ba 12Cl 5F 19,Z. Anorg. Allg. Chem. 622, 343347.CrossRefGoogle Scholar
March, A. (1932). “Mathematishe Theorie der Reglung nach der Korngestalt bei Affiner Deformation,” Z. Kristallogr. 81, 285297.CrossRefGoogle Scholar
Plato, W. (1907). “Erstarrungserscheinungen an anorganischen Salzen und Salzgemischen. II. Erstarrung von Salzgemischen und ihre thermischen Eigenschaften,” Z. Phys. Chem. (Munich) 58, 350372.CrossRefGoogle Scholar
Rodriguez-Carvajal, J. (1990). “FULLPROF: A Program for Rietveld Refinement and Pattern Matching Analysis,” in Collected Abstracts of Powder Diffraction Meeting (Toulouse, France), p. 127.Google Scholar
Rundqvist, S., and Jellinek, F. (1959). “The structures of Ni 6Si 2B, Fe 2P, and some related phases,” Acta Chem. Scand. 13, 425432.CrossRefGoogle Scholar
Sauvage, M. (1974). “Refinement of the structures of SrFCl and BaFCl,” Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem. 30, 27862787.CrossRefGoogle Scholar
Sheldrick, G. M. (1986). “SHELXS86: A Program for the solution of the crystal structures,” University of Göttingen, Germany.Google Scholar
Sheldrick, G. M. (1993). “SHELXL93: A Program for crystal structure refinement,” University of Göttingen, Germany.Google Scholar