Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-10T23:24:43.641Z Has data issue: false hasContentIssue false
  • English
  • Français

Tetrapotassium pyrophosphates γ- and δ-K4P2O7

Published online by Cambridge University Press:  13 March 2013

Armel Le Bail ,
Thomas Hansen  and
Wilson A. Crichton
Armel Le Bail*
Affiliation:
Institut des Molécules et des Matériaux du Mans, CNRS UMR 6283, Université du Maine, Avenue O. Messiaen, 72085 Le Mans, France
Thomas Hansen
Affiliation:
Institut Laue Langevin, 38042 Grenoble, France
Wilson A. Crichton
Affiliation:
European Synchrotron Radiation Facility, BP 220, 38043 Grenoble, France
*
a)Author to whom correspondence should be addressed. Electronic mail: armel.le_bail@univ-lemans.fr
Get access Rights & Permissions [Opens in a new window]

Abstract

The structures of γ- and δ-K4P2O7 are solved by X-ray powder diffraction (conventional laboratory X-ray and synchrotron data, respectively), both in hexagonal symmetry (aγ = 5.9645(3) Å, cγ = 14.4972(8) Å, Vγ = 446.64(4) Å3 at 300 °C, Zγ = 2, space group P63/mmc; aδ = 10.211 45(7) Å, cδ = 42.6958(4) Å, Vδ = 3855.59(7) Å3 at room temperature, Zδ = 18, space group P61) with cell–supercell relations $a_\delta \approx a_\gamma \sqrt{3}$ and cδ ≈ 3 cγ. In the experimental conditions, the expected β/γ transition previously announced at 486 °C is not observed; the γ-form is stable at least up to the maximum temperature of our measurements (700 °C). In the γ-form, similar to the orthorhombic form of Na4P2O7, idealized, the pyrophosphate group is in eclipsed conformation, the K+ cations occupying three different coordinations. In the δδ-form, two of the three different [P2O7]4− groups are staggered and one eclipsed, the K+ cations occupying 12 independent sites.

Keywords

tetrapotassium pyrophosphatepowder diffractioncrystal structureab initio
Type
Technical Articles
Information
Powder Diffraction , Volume 28 , Issue 1 , March 2013 , pp. 2 - 12
Copyright
Copyright © International Centre for Diffraction Data 2013 

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

Brese, N. E. and O'Keefe, M. (1991). “Bond-valence parameters for solids,” Acta Crystallogr. B47, 192–197.CrossRefGoogle Scholar
de Wolf, P. M. (1968). “A simplified criterion for the reliability of a powder pattern indexing,” J. Appl. Crystallogr. 1, 108–113.CrossRefGoogle Scholar
Dowty, E. (2006). CRYSCON, version 1.2.1, Shape Software, Kingsport, USA.Google Scholar
Dumas, Y. and Galigné, J. L. (1974). “Structure cristalline du pyrophosphate tétrapotassique trihydraté, K4P2O7•3H2O,” Acta Crystallogr. B30, 390–395.CrossRefGoogle Scholar
Durif, A. (1995). Crystal Chemistry of Condensed Phosphates (Plenum Press, New York) p. 17.CrossRefGoogle Scholar
Fitch, A. N. (2004). “The high resolution powder diffraction beam line at ESRF,” J. Res. Natl. Inst. Stand. Technol. 109, 133–142.CrossRefGoogle ScholarPubMed
Gražulis, S., Chateigner, D., Downs, R. T., Yokochi, A. F. T., Quirós, M., Lutterotti, L., Manakova, E., Butkus, J., Moeck, P. and Le Bail, A. (2009). “Crystallography Open Database – an open-access collection of crystal structures,” J. Appl. Crystallogr. 42, 726–729.CrossRefGoogle ScholarPubMed
Le Bail, A. (2001). “ESPOIR: a program for solving structures by Monte Carlo from powder diffraction data,” Mater. Sci. Forum 378–381, 65–70.CrossRefGoogle Scholar
Le Bail, A. (2004). “Monte Carlo indexing with McMaille,” Powder Diffr. 19, 249–254.CrossRefGoogle Scholar
Le Bail, A. (2005). “Whole powder pattern decomposition methods and applications – a retrospection,” Powder Diffr. 20, 316–326.CrossRefGoogle Scholar
Le Bail, A. (2008). “Structure solution,” in Principles and Applications of Powder Diffraction, edited by Clearfield, A., Reibenspies, J. and Bhuvanesh, N. (Wiley, New York), pp. 261–309.Google Scholar
Le Bail, A, Cranswick, L. M. D., Adil, K., Altomare, A., Avdeev, M., Cerny, R., Cuocci, C., Giacovazzo, C., Halasz, I., Lapidus, S. H., Louwen, J. N., Moliterni, A., Palatinus, L., Rizzi, R., Schilder, E. C., Stephens, P. W., Stone, K. H., and van Mechelen, J. (2009). “Third structure determination by powder diffractometry round robin (SDPDRR-3),” Powder Diffr. 24, 254–262.CrossRefGoogle Scholar
Leung, K. Y. and Calvo, C. (1972). “The structure of Na4P2O7 at 22 °C,” Can J. Chem. 50, 2519–2526.CrossRefGoogle Scholar
Morey, G. W., Boyd, Jr F. R., England, J. L. and Chen, W. T. (1955). “The system NaPO3–Na4P2O7–K4P2O7–KPO3,” J. Am. Chem. Soc. 77, 5003–5011.CrossRefGoogle Scholar
Napper, J. D., Layland, R. C., Smith, M. D. and zur Loye, H.-C. (2004). “Crystal growth and structure determination of the new silicate K3ScSi2O7,” J. Chem. Crystallogr. 34, 347–351.CrossRefGoogle Scholar
Rietveld, H. M. (1969). “A profile refinement method for nuclear and magnetic structures,” J. Appl. Crystallogr. 2, 65–71.CrossRefGoogle Scholar
Rodriguez-Carvajal, J. (1993). “Recent advances in magnetic-structure determination by neutron powder diffraction,” Physica B, 192, 55–69.CrossRefGoogle Scholar
Sandström, M. (2006). “Structural and solid state EMF studies of phases in the CaO–K2O–P2O5 system with relevance for biomass combustion,” PhD Thesis, Umeå University, Sweden.Google Scholar
Sandström, M., Fischer, A. and Boström, D. (2003). “CaK2P2O7,” Acta Crystallogr. E59, i139–i141.Google Scholar
Shekhtman, G. Sh., Smirnov, N. B. and Burmakin, E. I. (2000). “Electroconductivity of solid solutions in the K4P2O7-Rb4P2O7 system,” Russ. J. Electrochem. 36, 435–437.CrossRefGoogle Scholar
Sheldrick, G. (2008). “A short history of SHELX,” Acta Crystallogr. A64, 112–122.CrossRefGoogle Scholar
Smith, G. S. and Snyder, R. L. (1979). “FN: a criterion for rating powder diffraction patterns and evaluating the reliability of powder-pattern indexing,” J. Appl. Crystallogr. 12, 60–65.CrossRefGoogle Scholar
Szczygieł, I., Znamierowska, T. and Mizer, D. (2010). “Phase equilibria in the oxide system Nd2O3–K2O–P2O5,” Solid State Sci. 12, 1205–1210.CrossRefGoogle Scholar
Vidican, I., Smith, M. D. and zur Loye, H. -C. (2003). “Crystal growth, structure determination, and optical properties of new potassium-rare-earth silicates K3RESi2O7 (RE = Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu),” J. Solid State Chem. 179, 203–210.CrossRefGoogle Scholar
Znamierowska, T. (1978). “Phase equilibria in the system CaO–K2O–P2O5. Part III. The partial system CaK2P2O7–K4P2O7–KPO3,” Pol. J. Chem. 52, 1889–1895.Google Scholar