Hostname: page-component-78c5997874-mlc7c Total loading time: 0 Render date: 2024-11-14T23:38:59.508Z Has data issue: false hasContentIssue false
  • English
  • Français

Synthesis and Rietveld refinements of monoclinic Er2BaF8

Published online by Cambridge University Press:  06 March 2012

S. N. Achary ,
M. D. Mathews  and
A. K. Tyagi
S. N. Achary
Affiliation:
Applied Chemistry Division, Bhabha Atomic Research Centre, Mumbai (400 085), India
M. D. Mathews
Affiliation:
Applied Chemistry Division, Bhabha Atomic Research Centre, Mumbai (400 085), India
A. K. Tyagi*
Affiliation:
Applied Chemistry Division, Bhabha Atomic Research Centre, Mumbai (400 085), India
*
a)Fax: 0091-22-5505050. Electronic mail: aktyagi@magnum.barc.ernet.in.
Get access Rights & Permissions [Opens in a new window]

Abstract

The compound Er2BaF8 is prepared by heating appropriate amounts of BaF2 and ErF3 at 900 °C for 18 h in a dry argon filled quartz ampoule. The polycrystalline sample obtained was characterized by a Rietveld refinement of the observed powder diffraction data. This compound crystallizes in a monoclinic lattice with unit cell parameters: a=6.9620(2), b=10.4960(3), c=4.2541(1) Å and β=99.685(1)°, V=306.14(1) Å3, Z=2, (space group C 2/m, No. 12). The structure analysis reveals the presence of one kind of Ba and Er atoms in the unit cell. There are three different kinds of fluorine atoms, namely F1, F2, and F3 in the ratio of 8:4:4. The Er atoms form a square-antiprism polyhedron with eight fluorine atoms, which share three of its edges to form a ring of six ErF8 polyhedra. The rings of ErF8 polyhedra are connected via two opposite corners along the c-axis of the unit cell. The voids formed within the rings are occupied by Ba atoms, which maintain a twelve-coordination polyhedron with the fluorine atoms. As per the Rietveld analysis, the F3 site may exist as a disordered state by shifting the fluorine atom from the two-fold axes. © 2004 International Centre for Diffraction Data.

Type
Technical Articles
Information
Powder Diffraction , Volume 19 , Issue 3 , September 2004 , pp. 265 - 269
Copyright
Copyright © Cambridge University Press 2004

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

Achary S. N. (2003). “Preparation, Characterization and Applications of Rare-earth based mixed fluorides,” Doctoral Dissertation, University of Mumbai.Google Scholar
Fouassier, C. (1985). Solid Inorganic Fluorides: Chemistry and Physics, edited by P. Hagenmüller (Academic, New York), p. 484.Google Scholar
Greis, O. and Haschke, J. M. (1982). “Rare earth fluorides,” in Handbook on the Phys. and Chem. of Rare Earths, edited by K. A. Gschneidner and L. Eyring (North-Holland, Amsterdam), p. 387.Google Scholar
Greis, O., Stede, P., and Keiser, M. (1981). “Prepration and Characterization of the ternery compounds BaRE2F8, with RE=Dy-Lu and Y,” Z. Anorg. Allg. Chem. ZAACAB 477, 133–138. zaa, ZAACAB CrossRefGoogle Scholar
Guilbert, L. H., Gesland, J. Y., Bulou, A., and Retoux, R. (1993). “Structure and Raman spectroscopy of Czochralski-grown barium yttrium and barium ytterbium fluorides crystals,” Mater. Res. Bull. MRBUAC 28, 923–930. mrb, MRBUAC CrossRefGoogle Scholar
Hoppe, R. (1979). “Effective coordination number and mean fictive ionic radius,” Z. Kristallogr. ZEKRDZ 150, 23. zek, ZEKRDZ CrossRefGoogle Scholar
Izotova, O. E.and Aleksandrov, V. B. (1970). “The crystal structure of BaTm2F8” Dokl. Akad. Nauk SSSR DANKAS 192, 1037–1039. dan, DANKAS Google Scholar
Kaminiskii, A. A., Butashin, A. V., Hulliger, J., Egger, Ph., Bagayev, S. N., Eicher, H. J., Findeisen, J., Liu, B., Tauber, U., Peuser, P., and Sulyanov, S. N. (1998). “New anisotropic rare-earth fluorides BaR2F8 (R=Y, Dy-Lu): Growth and characterization” J. Alloys Compd. JALCEU 275–277, 442–446. jal, JALCEU CrossRefGoogle Scholar
Patwe, S. J., Achary, S. N., and Tyagi, A. K. (2002). “Synthesis and characterization of Ba1−xErxF2+x (0.00≤x≤1.00),” Mater. Res. Bull. MRBUAC 37, 2243–2253. mrb, MRBUAC CrossRefGoogle Scholar
Rodriguez-Carvajal, J. (2000). “FULLPROF 2000: A Program for Rietveld, Profile Matching and Integrated Intensity Refinements for X-ray and Neutron Data. Version 1.6.” Laboratoire Leon Brillouin, Gif sur Yvette, France.Google Scholar
Sirota, M. I., Bukkvetskii, B. V., and Simonov, V. I. (1975). “Example of automatic deciphering of atomic structure of a crystal by superposition method,” Kristallografiya KRISAJ 20, 642–643. krg, KRISAJ Google Scholar
Sobolev, B. P.and Tkachenko, N. L. (1982). “Phase diagrams of BaF2–(Y,Ln)F3 systems” J. Less-Common Met. JCOMAH 85, 155–170. jco, JCOMAH CrossRefGoogle Scholar
Sobolev, B. P. (1992). “Multi-component fluoride single crystals: Current status of their synthesis and prospects” in Growth of Crystal, edited by E. I. Givargizov and S. A. Grinberg (Consultant Bureau, New York), Vol. 18, pp. 197–211.Google Scholar
Tkachenko, N. L., Garashina, L. S., Izotova, O. E., Aleksandrov, V. B., and Sobolev, B. P. (1973). “Phase equilibria in BaF2–(Y,Ln)F3 systems” J. Solid State Chem. JSSCBI 8, 213–218. jss, JSSCBI CrossRefGoogle Scholar