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Crystal structure and reference X-ray pattern of Ba4Ti10Al2O27

Published online by Cambridge University Press:  10 January 2013

J. A. Kaduk
Affiliation:
Amoco Corporation, Naperville, Illinois 60566
B. H. Toby
Affiliation:
MSEL, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
W. Wong-Ng
Affiliation:
MSEL, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
W. Greenwood
Affiliation:
Geology Department, University of Maryland, College Park, Maryland 20742

Abstract

The crystal structure of Ba4Ti10Al2O27 has been refined in a joint Rietveld refinement using neutron and X-ray powder data. The compound crystallizes in the monoclinic space group C2/m, with a=19.7057(3), b=11.3575(2), c=9.8318(2) Å, β=109.218(1)°, and V=2077.81(5) Å3. It is isostructural to Ba4Ti10Fe2O27 and Ba4Ti11ZnO27, and consists of a complex network of corner- and edge-sharing Ti/Al octahedra. The structure can best be described based on close-packed O/Ba-O layers in an 8-layer (8L) chhcchhc sequence. Out of a total of ten Ti/Al sites, Al was found to substitute for Ti mainly in four sites, and the remaining six sites were predominantly occupied by Ti. The unit cell contents derived from the refined site occupancies are Ba16Ti40.48Al7.52O108, essentially identical to the expected Ba16Ti40Al8O108. A reference diffraction pattern of this phase is also reported.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1998

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References

Brese, N. E., and O’Keefe, M. (1991). “Bond Valence Parameters for Solids,” Acta Crystallogr., Sect. B: Struct. Sci. B47, 192197.CrossRefGoogle Scholar
Brown, I. D., and Altermatt, D. (1985). “Bond Valence Parameters Obtained from a Systematic Analysis of the Inorganic Crystal Structure Database,” Acta Crystallogr., Sect. B: Struct. Sci. B41, 244247.CrossRefGoogle Scholar
Fischer, R. X. (1985). “STRUPLO84, A Fortran Program for Crystal Structure Illustrations in Polyhedral Representation,” J. Appl. Crystallogr. 18, 258262.CrossRefGoogle Scholar
Larson, A. C., and Von Dreele, R. B. (1994). “GSAS, The General Structure Analysis System,” Los Alamos National Laboratory.Google Scholar
Lindsay, C. G., Rawn, C. J., and Roth, R. S. (1994). “Powder X-ray Diffraction Data for Ba 4ZnTi 11O 27 and Ba 2ZnTi 5O 13,” Powder Diffr. 9, 5662.CrossRefGoogle Scholar
Powder Diffraction File, produced by the International Centre for Diffraction Data, 12 Campus Blvd., Newtown Square, PA 19073-3273.Google Scholar
Rietveld, H. M. (1969). “A Profile Refinement Method for Nuclear and Magnetic Structures,” J. Appl. Crystallogr. 2, 6571.CrossRefGoogle Scholar
Roth, R. S., Rawn, C. J., Lindsay, C. G., and Wong-Ng, W. (1993). “Phase Equilibria and Crystal Chemistry of the Binary and Ternary Barium Polytitanates and Crystallography of the Barium Zinc Polytitanates,” J. Solid State Chem. 104, 99118.CrossRefGoogle Scholar
Schmachtel, J., and Müller-Buschbaum, H. (1981). “Ein Neues Quaternares Oxotitanat: Ba 4Ti 10Al 2O 27,” Z. Anorg. Allg. Chem. 472, 8994.CrossRefGoogle Scholar
Vanderah, T. A., Wong-Ng, W., Huang, Q., Roth, R. S., Geyer, R. G., and Goldfarb, R. B. (1997). “Crystal Structures and Properties of Ba 4Fe 2Ti 10O 27 and Ba 3Fe 10TiO 20,” J. Phys. Chem. Solids 58, 14031415.CrossRefGoogle Scholar