BaSnF4 fast ion conductor: Variations versus the method of preparation and anomalous temperature variation of the quadrupole splitting
A new method of preparation of high performance fluoride ion conductor, BaSnF4, by water leaching of newly discovered barium tin(II) chloride fluorides, has been designed, and the materials have been studied and compared to the solid prepared by the usual dry method. The unit-cell parameters and crystallite dimensions were found to vary with the method of preparation. In addition, the crystallite dimensions were found to be highly anisotropic for the samples obtained by the wet method. The Mössbauer spectrum is made of a large tin(II) quadrupole doublet, and a broad tin(IV) oxide peak due to surface oxidation. The tin(II) spectrum is in agreement with covalently bonded tin(II) having a strongly stereoactive lone pair. An unusually high dependence of the quadrupole splitting at low temperatures was observed (5.8 times larger than for α-SnF2).
Key wordsbarium tin fluoride ionic conductor Mössbauer spectroscopy synthetic methods
Unable to display preview. Download preview PDF.
- 3.Dénès, G.: In: Solid State Ionics IV, Mater. Res. Soc. Symp. Proc., Boston 1994, vol. 369, p. 295 (1995)Google Scholar
- 5.Dénès, G., Pannetier, J., Lucas, J.: C. R. Acad. Sci. Paris 280C, 831 (1975)Google Scholar
- 8.Cullity, B.D.: In: Elements of X-ray Diffraction, 2nd ed., p. 263 and 444. Addisson-Wesley, Reading, MA (1955)Google Scholar
- 9.Dénès, G., Madamba, M.C., Parris, J.M.: In: Solid State Ionics IV, Mater. Res. Soc. Symp. Proc., Boston 1994, vol. 369, p. 463 (1995)Google Scholar
- 10.Dénès, G., Madamba, M.C.: Mater. Struct. 3, 227 (1996)Google Scholar